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Model Forum / Radio Controlled / Air Models / February 2004Li Poly batteries, fantastic
Hi, In only a few months since I've been introduced to Li Poly batteries, the developments in Lithium Polymer batteries grew in leaps and bounds. Please witness the following specs and prices; 2 series, 8.5amp (nominal) li-poly 850mah 7.4 volt pack $29.28 3 series, 11amp (nominal) li-poly 1100mah 11.1 volt pack $53.52 2S3P, 33amp (nominal) li-poly 3300mah 7.4 volt pack $116.64 2600-4S4P, 104amp (nominal) li-poly 10400mah 14.8 volt pack $465.92 10S3P, 78amp (nominal) li-poly 7800mah 37 volt pack $873.60 These people make packs on order and have a huge list. I have only a partial list here. Perhaps some of you already knew about this, but I could paste their web site from which this info was derived if it's not unethical to advertise, but not for me? Wan > Hi, > [quoted text clipped - 18 lines] > > Wan try www.cheapbatterypacks.com > > Hi, > > [quoted text clipped - 20 lines] > > try www.cheapbatterypacks.com I checked into your web site and I believe the batteries there are basically of the smaller types, right? See if this is not more comprehensive? http://www.tanicpacks.com/BatteryListing.htm >>>Hi, >>> [quoted text clipped - 22 lines] > > I checked into your web site Not mine I assure you. and I believe the batteries there are > basically of the smaller types, right? See if this is not more > comprehensive? > > http://www.tanicpacks.com/BatteryListing.htm Tanics are also very good cells and have had a lot of positive feedback on teh E-zone. Some say they are indeed the same cells as the Irates. I don't think you will be disappointed with either. > >>>Hi, > >>> [quoted text clipped - 37 lines] > > I don't think you will be disappointed with either. I should have said the website you presented. Thanks. Perhaps you may have done some testing on these batteries? It's just that I am awed by the rapid progress made in the field of batteries. Who knows what else technology may bring forth? Wan >>>>>Hi, >>>>> [quoted text clipped - 44 lines] > It's just that I am awed by the rapid progress made in the field of > batteries. Who knows what else technology may bring forth? The cells are good enough: More work needs to be done to make them less l=iable to explode under abuse, and to make theme cheaper. > Wan | 10S3P, 78amp (nominal) li-poly 7800mah 37 volt pack $873.60 And in case somebody wasn't paying attention, this is exactly why we don't see many large electrics yet. This battery pack puts out up to 2900 watts, or 3.8 HP. This would be comparable to an OS FX 1.6 engine, which puts out up to 3.7 HP. And costs $270. This battery pack will put out that much power for 6 minutes *at best* (since it's a 10C discharge rate.) And this is just the battery pack -- there's no ESC, no motor (with this much money going inot just one battery pack, it's silly not to get the best brushless motor you can find. And of course, it won't be 100% efficient, reducing the actual power you get.) You're looking at many hundreds of dollars more for that. And of course, you usually want at least two battery packs ... the costs add up very fast. Some say that it all evens out in the end, that you're essentially buying all your fuel up front. There's some truth to that, but it still seems that large electrics still cost a lot more, both up front and over all. The `sweet spot' for electrics is still the Speed 400 and smaller sizes. Once you get larger, the price goes WAY up. If you double the power, you basically double the price. (Compare this to glow, where if you double the power, you add maybe 20% to the cost.) That said, I bought some Li-poly packs for my smaller electrics, a XE2 with an Astroflight 020, and an Electrifly with a geared Speed 400. Both got two cell packs, the first was a Tanic 2200 pack, and the second a 1700 mAh pack of some sort. They're quite nice, though I wish I had a three cell pack in the XE2 -- it has less power now, but a lot more duration. Someday (hopefully soon!) these batteries will come way down in price. That will be a very good thing!  SignatureDoug McLaren, dougmc@frenzy.com Don't spend two dollars to dry clean a shirt. Donate it to the Salvation Army instead. They'll clean it and put it on a hanger. Next morning buy it back for seventy-five cents. --William Coronel I am also waiting for the cost to come down. The fuel arguement is only valid when thinking long term. I don't know anyone who paid for all the gas their car would use at the time they bought the car. Another thing to consider is the charger for such battery beasts! > | 10S3P, 78amp (nominal) li-poly 7800mah 37 volt pack $873.60 > [quoted text clipped - 41 lines] > Salvation Army instead. They'll clean it and put it on a hanger. Next > morning buy it back for seventy-five cents. --William Coronel > I am also waiting for the cost to come down. The fuel arguement is only > valid when thinking long term. I don't know anyone who paid for all the gas > their car would use at the time they bought the car. Heck, not many people pay for the car upfront! Lease those lithiums. Theres a new business oopportinity for you Paul! > Another thing to consider is the charger for such battery beasts! Not particularly hard to engineer. 8A at 40V or so. The point is, you still have to pay for all the power up front with electrics. That is what's keeping them in the minority so far. How many people would even start glow if they had to pay for 100 gallons of fuel every time they thought about a new plane? > > I am also waiting for the cost to come down. The fuel arguement is only > > valid when thinking long term. I don't know anyone who paid for all the gas [quoted text clipped - 7 lines] > > Not particularly hard to engineer. 8A at 40V or so. > The point is, you still have to pay for all the power up front with > electrics. That is what's keeping them in the minority so far. How many > people would even start glow if they had to pay for 100 gallons of fuel > every time they thought about a new plane? Paul, you know that the same battery pack may be used in different planes, don't you? Then you would not have to think about paying for 100 gallons of fuel each time you want a new plane. I know you have a lot more experience with model planes than I, but I still believe electrics are do-able now cost wise. Witness the hundreds of electric flyers whose .40 to .60 sized planes that are performing as well and flying even longer than some gas powered planes now. With my limited experience on Li Poly, I'm hoping somebody would be able to illustrate my point. Wan > > > I am also waiting for the cost to come down. The fuel arguement is only > > > valid when thinking long term. I don't know anyone who paid for all the [quoted text clipped - 8 lines] > > > > Not particularly hard to engineer. 8A at 40V or so. Wan, I completely believe that electrics will continue to grow in popularity, but not become dominant until something is done about the entry fee. You can get a VERY nice .50 size glow powered model, ready to fly, for under $250. That includes plane, radio, engine and fuel, etc. To get equivalent performance with electrics still costs much more. Some of the examples here talk about near $1000 just for one battery which has the potential for performance in the 1.5 glow power range. Add in the cost of motor, speed controller and charger! And yo have ONE flight. Want two? Wait while your battery charges or spend another $1000 for a second battery. Electrics are getting there, but are still hampered by cost in anything over the speed 400 range. > > The point is, you still have to pay for all the power up front with > > electrics. That is what's keeping them in the minority so far. How many [quoted text clipped - 28 lines] > > > > > > Not particularly hard to engineer. 8A at 40V or so. > Wan, > > I completely believe that electrics will continue to grow in popularity, but > not become dominant until something is done about the entry fee. You can > get a VERY nice .50 size glow powered model, ready to fly, for under $250. > That includes plane, radio, engine and fuel, etc. You cam get a ready to go firebird for under $100. Its perfectly possible to get an sub 250 dollar leccy plane, it just isn't '40' sized. THAT is what 'entry level' leccy flyers start with. They can always get greased up later on...:-) Again, I couldnt be happier with my electric Slowstick. Mind you, we are talking about ENTRY level here, although two or more expert pilots with slowsticks and a few 6 foot combat streamers could have hours of fun (i sure do) - im getting away from the point. Screw the firebirds, they really do look like wal-mart toys. Not that the SS looks beautiful, but at least it is Hobby Grade stuff. Logically, one would 'enter' the hobby with an inexpensive electric foamie (such as i did) Move on to a bigger/faster/sportier electric OR a .40 trainer plane, depending on outside factors like your proximity to a club, LHS stock, luck with the electrics, etc. From there, you can either go with an even bigger electric, or a sportier glow plane - this is where the cost of electric really starts getting silly. Ive learned so much about handling a plane in a few short months with the SS - i couldnt imagine trying to learn the 'old-fashioned' way with a balsa/glow trainer from the start. I did, however, just apply to the AMA, and im looking for a local club. Hopefully, i can hook up with somebody there who can help me learn to fly this old Eaglet that was donated to me. It should be easy to get used to, but i dont wanna take a chance with crashing a balsa/glow plane first time out. Mike > > Wan, > > [quoted text clipped - 9 lines] > > They can always get greased up later on...:-) You are comparing apples to oranges AGAIN. > > Wan, > > [quoted text clipped - 9 lines] > > They can always get greased up later on...:-) > You are comparing apples to oranges AGAIN. No, I was pointing out that you were, AGAIN. >>>Wan, >>> [quoted text clipped - 18 lines] >> >>They can always get greased up later on...:-) Maybe you can't handle anything above a Firebird so you think it is the same as a .50 powered plane. That is the only reason I can see for calling them the same thing. You only want to compare price because that is the issue. You can't get equivalent performance in anyting over speed 400 without the price going way over that of glow. And, you have to consider ALL of the costs, not just the plane and batteries, > > You are comparing apples to oranges AGAIN. > [quoted text clipped - 22 lines] > >> > >>They can always get greased up later on...:-) Paul, > You can > get a VERY nice .50 size glow powered model, ready to fly, for under $250. > That includes plane, radio, engine and fuel, etc. To get equivalent > performance with electrics still costs much more. Not very accurate. Most entry level EP's are as you say, except some like the Aerobird Challenger. You can get a HobbyZone Aerobird Challenger for around $150.00 which includes EVERYTHING needed to get started & is far more durable & forgiving than most glow trainers. I fly mine when some glow's think it's too windy & fail to show up at the field. The ABC even comes with 2 flight modes, so beginners & advanced pilots can have fun with them. Put in the optional 7 cell/900 mAh battery pack ($30.00 avg) & it screams! -- Jim L. https://sourceforge.net/projects/virtual-access/ Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 Like TNP, you are comparing apples to oranges. The entry fee I was talking about is not entry LEVEL. > Paul, > [quoted text clipped - 17 lines] > https://sourceforge.net/projects/virtual-access/ > Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 Paul, > Like TNP, you are comparing apples to oranges. The entry fee I was talking > about is not entry LEVEL. That's the whole point here, entry level costs of glow vs electric. This time you're off base, as my comparison *IS* entry level. No two ways about it. My example comes complete & includes everything needed to get airborne. A simple head to head comparison of what it takes to start in EP. -- Jim L. https://sourceforge.net/projects/virtual-access/ Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 I was NOT TALKING ENTRY LEVEL AND NEITHER WAS ANYONE BUT YOU TWO. When I say entry fee, I mean the cost to get a specific level of airplane to the flying field, in flight ready condition. You guys read something into it that I did not type. > Paul, > [quoted text clipped - 11 lines] > https://sourceforge.net/projects/virtual-access/ > Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 Paul, > When I say entry fee, I mean the cost to get a specific level of airplane to > the flying field, in flight ready condition. Exactly what I countered you with in my reply about the ABC, exactly the same thing. You seem to have selective memory in remembering only what supplements your position. You stated; > You can > get a VERY nice .50 size glow powered model, ready to fly, for under $250. > That includes plane, radio, engine and fuel, etc. To get equivalent > performance with electrics still costs much more. To which my statement about the ABC was a direct & clear counter claim supporting EP, AND at a cheaper cost as well. > You guys read something into > it that I did not type. Not true, as shown above in your very own words. -- Jim L. https://sourceforge.net/projects/virtual-access/ Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 > Paul, > [quoted text clipped - 6 lines] > about it. My example comes complete & includes everything needed to get > airborne. A simple head to head comparison of what it takes to start in EP. Ah, but for Paul, the only thing that counts is an EP that will turn EXACTLY the same prop as his 40 engines at EXACTLY the same RPM, and cost less. Never mind that that is probably the most stupid and wasteful way to operate an E-plane, that is all he understands and you can't teach old dogs new tricks. :-) > -- > > Jim L. > https://sourceforge.net/projects/virtual-access/ > Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 TNP, It's more an issue of the 'old guard' (some die hard glow, but not all )seeing EP as encroaching on their turf. There's some valid arguments against EP, as cost comparisons above a certain level show. Also, many early EP planes were just plain junk. Not so now. With 10, 20, 30, 40 or more years as glow only fliers, EP's recent rise up to, and now leveling off with glow performance, isn't something some will openly embrace. I like both my glow's & EP. I just don't have a number of years on glow only, so I'm not inclined to be anti either way. I will not however, let erroneous claims such as Paul tries making, to go unchallenged. One old timer in our club has flown for around 30+ years. He can fly his glow's inverted about 3-4' off the deck, as good as anyone does with theirs right side up. His flying & building abilities are astounding! He's only this Winter, decided to build his very first EP plane, somewhat due to what my EP - ABC and other EP planes are now capable of. There's room for both. We just don't need misinformation. -- Jim L. https://sourceforge.net/projects/virtual-access/ Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 > There's room for both. We just don't need misinformation. I agree whole heartedly. If its a question of a novice gettng some kit and going flying, there is not much cost difference between E-fight and a basic glo trainer. The e-plane will be smaller, that's all. In a poll on the e-zone recently, that vast majority of E-flyers were self taught. They got spomehing and bunged it in the air, it bounced, they bunged it again, and eventually wobbled their way to some sort of piloting skill. Much as I did. Unless you have access to a friendly club, its a lot easier to learn that way. The thought of bunging the average 40 trainer in the air and bouncing it scares the pants off me. They really do NEED qualified instruction. After that tho, its all a matter of taste. The big delusion is that flying model aircraft is all about what our average glo pilot thinks it is all about. It isn't. Thats just where it has ended up. In my youth it was all about stick and tissue models and rubber bands, or chasing diesel powered old timers across acres of countryside. The fun was in the building and the challenge of actually getting it in the air. E-flight is a whole new ball game with different rules. Enjoy it for what it is, don't try and pretend its just a different sort of .40 engine to stick in the same model and get identical behaviour. Bullshit. Read my posts. > TNP, > [quoted text clipped - 24 lines] > https://sourceforge.net/projects/virtual-access/ > Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 Paul, > Bullshit. Read my posts. Regarding the blatant misinformation you're spewing about EP, yep, THAT is bullshit. Your shade tree/arm chair misinformational approach to EP, shows you truly are out of your element with them. You DO know a lot about R/C aircraft overall & glow's in particular, but regarding accurate knowledge about EP your way out in left field. -- Jim L. https://sourceforge.net/projects/virtual-access/ Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 You can really be a dickhead sometimes. You only want to compare toys to larger planes to make your point. Compare like performance instead of justifying price. > > Paul, > > [quoted text clipped - 20 lines] > > https://sourceforge.net/projects/virtual-access/ > > Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 > Like TNP, you are comparing apples to oranges. The entry fee I was talking > about is not entry LEVEL. I see Paul, so basically following your logic, I have to spend 30bn dollars on developing some huge piston engines to get what any turbojet can do? Or every time I build a new model I have to buy a new transmitter for it? No, better than that, I have to buty a new truck to take it to the field in. Because I didn't have the sense to buy the right truck teh first time around, or the second, or the third? >>Paul, >> [quoted text clipped - 26 lines] >> https://sourceforge.net/projects/virtual-access/ >> Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 Where the hell do you get that analogy from? > > Like TNP, you are comparing apples to oranges. The entry fee I was talking > > about is not entry LEVEL. [quoted text clipped - 41 lines] > >> https://sourceforge.net/projects/virtual-access/ > >> Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 > Where the hell do you get that analogy from? From oir critcsim of the point I made that one does not buy a new pack of cells for every aeroplane, in the same way you don't buy a new transmitter, or a new vehicle to carry it in. >>>Like TNP, you are comparing apples to oranges. The entry fee I was >>> [quoted text clipped - 52 lines] >>>> https://sourceforge.net/projects/virtual-access/ >>>> Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 | From oir critcsim of the point I made that one does not buy a new pack | of cells for every aeroplane I do indeed buy new packs for most new electric planes I get. Why? Because most of the time, if I get a new electric plane, it's rather different than the ones I've already got, so requires a different battery pack in many cases. I may already have a small slow flier, and so my next plane would be a E3D plane, and the next might be a 0.20 sized aerobatic plane. All would have different power requirements, so would require different battery packs. At least two for each class of plane. | in the same way you don't buy a new transmitter, or a new vehicle to | carry it in. That analogy is flawed. My 9c radio has models set up for slow park fliers, 60 sized glow planes, powered gliders, non powered gliders aerobatic electic planes, etc. I don't have any giant scale stuff, but it could handle it if I did. My vehicle can handle all of these planes as well. But I don't have any battery packs that can. SignatureDoug McLaren, dougmc@frenzy.com I have never met a man so ignorant that I couldn't learn something from him. -Galileo Galilei > | From oir critcsim of the point I made that one does not buy a new pack > | of cells for every aeroplane [quoted text clipped - 8 lines] > requirements, so would require different battery packs. At least two > for each class of plane. Well more fool you. I have basically one IPS class pack (15W), one 400 class pack (100W), one 480 class pack (200W) , and will be getting a 600 class pack soon (350W). Any planes I build will be built around those pack sizes. So far the most I have spend on a single pack is $66. I estimate the 600 class pack will be around $100. If you are sane and build blocks of the same cells that can be assembled into different pack configurations, you can even assemble a 600 class pack from e.g. three 400 class ones. > | in the same way you don't buy a new transmitter, or a new vehicle to > | carry it in. [quoted text clipped - 9 lines] > > But I don't have any battery packs that can. Time to draw up a chart and make up some that will then. See, no matter what you do, TNP is always smarter and better than you. Hey, TNP, what do you do if you want to build a plane that DOESN"T match your current batteries? Settle for something else? Sounds like it. > > | From oir critcsim of the point I made that one does not buy a new pack > > | of cells for every aeroplane [quoted text clipped - 37 lines] > > Time to draw up a chart and make up some that will then. Bingo. You left out what a PITA it is to bring several of the EP planes that take diff packs out for a day of flying. Generally took me most of the prior day spent charging up two packs each for my 400X, Razor, and Yard Bee, each of which takes a different style or at least layout of pack. Throw in my Twinstar and I am hosed. This assumes one charger. Eventually I got a second charger. Still spent more time at the field re-charging packs than flying. Quite a lot of time waiting for that little red light to start blinking! I fly both, but prefer my glow planes for those reasons. Something else NOBODY takes in to account for the cost of EP: How much of your electricity bill goes to charging up all those packs? That aint free! You can bring a 12v tractor battery or equivalent to the field but that sucker has to be charged someplace too. Probably not comparable to the cost of glow fuel, but still a factor that should be considered as far as the total cost. I know that all those glowing LEDs in the garage are costing me something... SignatureDan KE6ERB AMA605992 I've heard the screams of the vegetables... http://fubar1.freeservers.com > > | From oir critcsim of the point I made that one does not buy a new pack [quoted text clipped - 23 lines] > > But I don't have any battery packs that can. | You left out what a PITA it is to bring several of the EP planes that take | diff packs out for a day of flying. Generally took me most of the prior day | spent charging up two packs each for my 400X, Razor, and Yard Bee, each of | which takes a different style or at least layout of pack. Throw in my | Twinstar and I am hosed. Hmm, I never had that much trouble with it. I do have two chargers though, so that helps. | This assumes one charger. Eventually I got a second charger. Still spent | more time at the field re-charging packs than flying. One reason why I do more slope flying than anything else now. I spend all my time flying. I usually land because I'm tired of flying after an hour or so -- not because I'm out of power. | Something else NOBODY takes in to account for the cost of EP: | How much of your electricity bill goes to charging up all those packs? That | aint free! It's damn cheap. One kilowatt hour costs around $0.10 (it's nowhere near this simple, but that's pretty close.) So if you've got a plane with a 500 watt motor (a pretty good sized electric -- yours are more in the 50-150 watt range except for the Twinstar, for which I have no idea), that's two hours of full throttle flying for $0.10. Of course, your batteries and charger aren't 100% efficient, but even with 50% efficiency it doesn't cost much. If you're charging from your car, you'll pay for this via reduced fuel efficiency, but it still won't be much. | You can bring a 12v tractor battery or equivalent to the field but that | sucker has to be charged someplace too. | Probably not comparable to the cost of glow fuel, but still a factor that | should be considered as far as the total cost. Not even close. | I know that all those glowing LEDs in the garage are costing me | something... A large number of wal-warts certainly adds up. And they use power even if your plane isn't plugged into it ... I don't use those wal-wart chargers much anymore. I just use my fast chargers as needed. SignatureDoug McLaren, dougmc@frenzy.com Captain Ahab just has to have his whale, didn't he? Well, I knew I was oversimplifying the fuel vs charging cost but the rabid EP guys act like batteries are recharged by divine intervention or something. I only had one charger at the time so with 3 diff battery types X2 there is quite a lot of time spent with that charger. My 12v chargers (I now have added a Triton) are run off of my Astron power supply which would be powering the charger and a cooling fan. Granted that probably doesnt add up to much but it does (especially here in So Cal where Bush's energy buddys screwed us) to something. I agree that sloping is about as close to free as you can get, other than charging the tx and rx. Another prob here in So Cal is the pyros setting the cool slope sites on fire, at least those near me. Looking good wind wise for tomorrow tho so I hope to hit the slope myself! Gotta maiden my new Mini-Blade. Be caregul! TNP is going to tell you how stupid you are for not making sure all your planes use the same batteries! > Bingo. > You left out what a PITA it is to bring several of the EP planes that take [quoted text clipped - 54 lines] > him. > > -Galileo Galilei Aw, man, I plonked that dude months ago. Besides, going by that logic, I would have to decide on one engine for all my glow planes and 86 the rest. Which one would I then keep? My Ultra Stick 60 (91FS)? My Uproar 40 (cept it has a .32SX on it, not a .40)? My .15 powered Hyper Bee? My Kaos (cept has a .51 and not a .40)? Guess I need to stop building my Super Sports 20. Forget about even STARTING my Super Sports 40 twin engine conversion. Oh wait! I CAN keep those! They all use the same type of BATTERY! Yay! SignatureDan KE6ERB AMA605992 I've heard the screams of the vegetables... http://fubar1.freeservers.com > Be caregul! TNP is going to tell you how stupid you are for not making sure > all your planes use the same batteries! [quoted text clipped - 62 lines] > > him. > > > -Galileo Galilei Where does that ever enter into the equation? Are you saying only buy one pack and transfer it between all your planes? Do you take the motor off each plane and switch it to another each time you want to fly it? Hell, you only get one flight as it is, now you want to limit that to one plane as well? Go back to my original post and read the post I was responding to. > > Where the hell do you get that analogy from? > [quoted text clipped - 58 lines] > >>>> https://sourceforge.net/projects/virtual-access/ > >>>> Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 > The point is, you still have to pay for all the power up front with > electrics. That is what's keeping them in the minority so far. How many > people would even start glow if they had to pay for 100 gallons of fuel > every time they thought about a new plane? We all had to fork out for radio transmitter, and charger tho? you don't start out in electrics on 40 sized models either. You strat out with a 50 dollar LIPO and a 3o dollar charger at the worst... Some people sepnd $1000 on transmitters. So wahts the odds with a pair of $500 packs? >>>I am also waiting for the cost to come down. The fuel arguement is only >>>valid when thinking long term. I don't know anyone who paid for all the [quoted text clipped - 10 lines] >> >>Not particularly hard to engineer. 8A at 40V or so. You are comparing apples to oranges. > > The point is, you still have to pay for all the power up front with > > electrics. That is what's keeping them in the minority so far. How many [quoted text clipped - 22 lines] > >> > >>Not particularly hard to engineer. 8A at 40V or so. > You are comparing apples to oranges. No, I was pointimng out that you were actually. >>>The point is, you still have to pay for all the power up front with >>>electrics. That is what's keeping them in the minority so far. How [quoted text clipped - 30 lines] >>>>> >>>>Not particularly hard to engineer. 8A at 40V or so. I was responding to a post regarding $1000 LiPos. Where does that fall into $50 toys? > > You are comparing apples to oranges. > [quoted text clipped - 34 lines] > >>>>> > >>>>Not particularly hard to engineer. 8A at 40V or so. > | 10S3P, 78amp (nominal) li-poly 7800mah 37 volt pack $873.60 > [quoted text clipped - 5 lines] > This would be comparable to an OS FX 1.6 engine, which puts out up to > 3.7 HP. And costs $270. However the FX puts it out at a not too useful RPM. To be fair that pack and a motor is probably nearer a 50cc motor. > This battery pack will put out that much power for 6 minutes *at best* > (since it's a 10C discharge rate.) [quoted text clipped - 4 lines] > 100% efficient, reducing the actual power you get.) You're looking at > many hundreds of dollars more for that. No, but it will be approaching 90% overall. How efficient is your glo prop? > And of course, you usually want at least two battery packs ... the > costs add up very fast. Some say that it all evens out in the end, > that you're essentially buying all your fuel up front. There's some > truth to that, but it still seems that large electrics still cost a > lot more, both up front and over all. Its true. Get into the big sizes and the cost does rocket. But you are not being totally fair here. There are more variables than you account for. > The `sweet spot' for electrics is still the Speed 400 and smaller > sizes. Once you get larger, the price goes WAY up. If you double the > power, you basically double the price. (Compare this to glow, where > if you double the power, you add maybe 20% to the cost.) Actually I'd slightl;y take issue, and say that the sweet spot is 100-500W, whicgh is speed 400 up to roughly 40 sized glo equivalents. In teh smaller planes, the radio gear has to be light, and that gest expensive, but planes around the 15-25 glo equivalent are not too expensive to electrify and not too small to need specialised gear. And you don't need a brushless motor to enjoy kithoum - the excess power and duration means rather les efficient (and much cheaper) motors still deliver good performance. > That said, I bought some Li-poly packs for my smaller electrics, a XE2 > with an Astroflight 020, and an Electrifly with a geared Speed 400. [quoted text clipped - 5 lines] > Someday (hopefully soon!) these batteries will come way down in price. > That will be a very good thing! I think it will be sooner rather than later. Ther are a lot of applications becomeing more sensible using lithium technology. I think there will be a huge incrase in use of these cells everywhere. Even current small cars would benefit from knocking a few ounds of teh wight by replacing the lead acid cell. If the price was right... | > | 10S3P, 78amp (nominal) li-poly 7800mah 37 volt pack $873.60 | > [quoted text clipped - 8 lines] | However the FX puts it out at a not too useful RPM. To be fair that pack | and a motor A high quality, and expensive motor. For example, an Aveox 1415/1.5 with a 3.7:1 gear ratio and a 14x10 prop can use 2500 watts (36 volts or so, 70 amps), giving a useful output of about 1700 watts, and costs about $250 for the motor and $300 for an appropriate ESC. (Are the ESCs really this expensive for larger motors?) (Maybe my choice of motor is very poor -- I've never actually really investigated putting together an electric plane this large before. At least not once I realized the small fortune I'd spend on batteries alone.) | is probably nearer a 50cc motor. Actually, that HP rating is at 9000 RPM. That's not that unreasonable -- certainly, it's not some screaming 0.049 engine. I doubt you'd need to go to 50 cc (3 ci) for similar performance. It depends on what you want. If you want speed, you want high RPMs and a small prop. If you want to do 3D, you want low RPMs and a big prop. Electics make the latter easier to do. | > This battery pack will put out that much power for 6 minutes *at best* | > (since it's a 10C discharge rate.) Don't disregard this. If you're using this much power, it won't be a very long flight. | > And this is just the battery pack -- there's no ESC, no motor (with | > this much money going inot just one battery pack, it's silly not to [quoted text clipped - 3 lines] | | No, but it will be approaching 90% overall. Probably not even too close to 90%, even for a brushless. And even less if you're running at the maximum output of the batteries. Run it through Motocalc ... it's very upsetting. 70% seems more realistic, and that's for a good motor. | How efficient is your glo prop? As for props, at some level, props are props. Gearing your motor down can give you more prop efficiency for slow flying, but you're still losing energy at the prop, glow or electric. | > And of course, you usually want at least two battery packs ... the | > costs add up very fast. Some say that it all evens out in the end, [quoted text clipped - 7 lines] | | There are more variables than you account for. Like? I guess you do need to add a throttle servo to the glow setup -- $10 or so. I don't think it's really reasonable to add the cost of chargers and starters and such to the prices when making comparisons. | > The `sweet spot' for electrics is still the Speed 400 and smaller | > sizes. Once you get larger, the price goes WAY up. If you double the [quoted text clipped - 4 lines] | 100-500W, whicgh is speed 400 up to roughly 40 sized glo | equivalents. A 0.40 sized glow engine can do a lot more than 500 watts. The OS FX 0.40 is rated at 1.36 hp -- 1033 watts. Yes, it's at a higher rpm than most need, but still, you're going to have a hard time getting similar performance out of an electric system that peaks out at 500 watts. Especially when the power system weights more than the glow power system. And I believe that power rating doesn't take into account the energy lost in the motor (and gearbox, if there is one) -- but the BHP rating of a glow/gas engine does. (Of course, IC engines are only like 25% efficient at best, but that's another matter entirely.) | In teh smaller planes, the radio gear has to be light, and that gest | expensive, but planes around the 15-25 glo equivalent are not too | expensive to electrify and not too small to need specialised gear. No, it's not too bad, but you'll still end up spending hundreds of dollars on batteries. It would take many many flights to run even $100 worth of fuel through a 0.25 glow engine plane. I've never found my (e-power) batteries to last (the internal resistances just seem to go up too much after that) more than a year or two, and I spend far more on batteries now than glow fuel. Of course, I also fly the electrics more than my glow planes ... | And you don't need a brushless motor to enjoy kithoum - the excess | power and duration means rather les efficient (and much cheaper) | motors still deliver good performance. When you're spending $900 per battery pack, it just makes good sense to spend a few hundred on the best motor you can get. Getting a better motor will save you money on the battery pack, because you can use a smaller (and cheaper) battery pack and get the same performance. For a $20 8 cell NiCd pack it's not a big deal. But for a $900 battery pack ... (For larger motors, doubling the power rating doesn't seem to double the cost. A brushless motor setup with 0.40 performance doesn't cost that much more than one with 0.09 performance.) | If the price was right... That's my beef. If I could get Li-poly cells for like 20% of the current cost, I'd go all electric tomorrow. SignatureDoug McLaren, dougmc@frenzy.com May you die in bed at 95, shot by a jealous spouse. > | > | 10S3P, 78amp (nominal) li-poly 7800mah 37 volt pack $873.60 > | > [quoted text clipped - 14 lines] > about $250 for the motor and $300 for an appropriate ESC. (Are the > ESCs really this expensive for larger motors?) Yes. To date its been a narrow market with low volume sales. There is no real reason they should be tho - the majority of the electronics is teh same for a 10A ESC as a 100A one, you just need a lot more power FETS stuck on teh back, and some way to drive them harder maybe added. > (Maybe my choice of motor is very poor -- I've never actually really > investigated putting together an electric plane this large before. At [quoted text clipped - 10 lines] > and a small prop. If you want to do 3D, you want low RPMs and a big > prop. Electics make the latter easier to do. Agreed. All out speed you will generally find a tuned pipe IC screamer is still the best. But for 3D work teh electric is more controllable and far more efficient overall as a a power train. > | > This battery pack will put out that much power for 6 minutes *at best* > | > (since it's a 10C discharge rate.) [quoted text clipped - 14 lines] > through Motocalc ... it's very upsetting. 70% seems more realistic, > and that's for a good motor. Mmm. The point is that that sort of power train is mostly used at or near max eficiency current, only peaking to full power for short bursts. You use full power really only when going for max rate of climb (keep that up and the model is out of sight soon) or absolute max speed. The rest of the time its throttled back a lot. So flight times are often surprisingly longer. Even EDF models with lower weeight lithium packs suddenly don't need full power all the time. Once you come down a few notches from flat out efficiency is better, current its lower and suddenlt flight times ae much longer. > | How efficient is your glo prop? > > As for props, at some level, props are props. Gearing your motor down > can give you more prop efficiency for slow flying, but you're still > losing energy at the prop, glow or electric. That is a misleading statement. An ungeared motor putting teh prop tips close to mach 1, and being strong enough at the root to cope with the centrifugal and torque pulse loads imposed by an IC motor, and heavy enough to act as a flywheel, is nowhere near as efficient as a thin bladed larger one geared down to the correct RPM for your model. This is teh MAJOR reason why people are surprised at how little E-power they need to fly a given glo airframe. Only in the case of >75mph models does teh glo engine start to match teh overall prop efficiency of the geared electric. > | > And of course, you usually want at least two battery packs ... the > | > costs add up very fast. Some say that it all evens out in the end, [quoted text clipped - 13 lines] > I don't think it's really reasonable to add the cost of chargers and > starters and such to the prices when making comparisons. Well, what kind of kit do you need to take to the field for a glo motor. - spare gloplug - glo starter battery - electric starter. - fuel pump - bag of baby wipes The field battery of course is commoon for both sorts. Additional model cost include - throttle servo - hefty engine mount - maybe custom muffler for the plane - fuel tank and plumbing - fuel proofer and generally strong firewall construction. And of course, fuel. Not irrelevant in a big model by any means. > | > The `sweet spot' for electrics is still the Speed 400 and smaller > | > sizes. Once you get larger, the price goes WAY up. If you double the [quoted text clipped - 10 lines] > similar performance out of an electric system that peaks out at 500 > watts. Well I disagree. For reasons stated above. Execpt when you DO need that extra RPM. > Especially when the power system weights more than the glow > power system. Its actually fairly close. Especially with a custom designed E-plane with all the beefed up structure to take engine vibraion removed, along with the fuel, tank, heavy prop and engine mount, muffler and servo. > And I believe that power rating doesn't take into > account the energy lost in the motor (and gearbox, if there is one) -- > but the BHP rating of a glow/gas engine does. (Of course, IC engines > are only like 25% efficient at best, but that's another matter > entirely.) As I said, the gains on the prop outweigh the efficiency losses in the box, or people wouldn't be using them. I am not trying to maintain teh E-planes are xcheaper at higher powers, bu they are not as expensive, or heavy, when costed out over a season or two, as you are making out. They also have some advantages in terms of reliability and ease of starting and very predictable throttle response that make them ideal for aerobats and multi-engined models. That is where the cost is worth bearing. Bigger aerobats, and multi-engined models. Also in the sub .25 type of sport model, where the costs are comparable. Only a big single engined sport or speed plane - 40 and up - is it really a bit enthisiastic to go electric. > | In teh smaller planes, the radio gear has to be light, and that gest > | expensive, but planes around the 15-25 glo equivalent are not too [quoted text clipped - 3 lines] > dollars on batteries. It would take many many flights to run even > $100 worth of fuel through a 0.25 glow engine plane. Well, I have spent $70 on a pack that will do 200W, about equivalent to .19 power wise by my estimation. Certainly .15 power. I can. and will, split that amongst several different models. I cannot reasonably unbolt an engine and swap it amongst two or three models in the same day. But I can only fly one plane at a time, and two such packs as that will allow me almost continuous back to back flying with short breaks in between on an unlimited number of models. Because the pack is light, and powerful, for general purpose sport models I can spend very little on the motors - cheap inefficient ones do just fine for average flying. Sure I have a 200W brushless setup that cost in excess of $100, but hat is not what I have to fly all the time, Thats reserved for planes that need to go straight up! > I've never found my (e-power) batteries to last (the internal > resistances just seem to go up too much after that) more than a year > or two, and I spend far more on batteries now than glow fuel. Of > course, I also fly the electrics more than my glow planes ... Again, there is a positive feedback mechanism. With Nicads, to fly at all, we needed to thrash the packs and motors just to fly at all. I've got some 2 year old packs that haven't been thrashed too much, that are still fine. All the signs are that the lithiums will be up there after two years as well. The key thing is to rememebr they are going to die of old age anyway whether you use them or not, and simply use them to the full, by splitting them amongst several models. You do NOT need to buy one pack per model. I've got one 100W pack and one 200W pack. That, plus a charger, is $200. Those will power ALL my planes built and on the board - about 7 in all. So that works out at $30 per plane or less. In the speed 400 sized cans, which are good enough for scale and modest planes cost is less than $50 per motor/ESC/box combo, and the 200W 480 class motors are not much more. Even the 480 class brushless is only $120 or so. So typically each model is costing me between $80 and $150 for the power train capital cost. Contrast that with an IC engine, servo, tank, mount etc. etc. and add fuel costs and its not very different. In general with two fully charged packs charged at home before flying, I can expect 40 minutes of continuous flight of the packs inclding general stuff like getting them packed up and checked out prior to flinging in the air, and the landing approach etc etc at low power. Then a 20 minute hiatus to recharge the packs, followed by 20 minutes flight/forty minutes wait AT THE VERY WORST WITH A FLAT PACK which they seldomn are. Its more like 15 minutes flight 10 minutes wait in practice. The amount of time glo planes seem to spend being started and fiddled with makes it very little worse. If you have three packs and two chargers its pretty much constinuous flying no breaks. Or indeed three packs and one charger will allow you to take 45 minutes of continuous power to the field ready to go. More than most glo pilots except the chopper boys seem to actually spend in the air anyway. Apples and oranges. Unless you MUST have a 40 powered or bigger plane, electrivc is cheap, and convenient. Why have a 40 powerd plane? Because that is the 'sweet spot' for IC. That's where its at its cheapest really. Slightly smaller is the sweet spot costwise for electrics. Once you have enough packs, you don't need to buy more for new models. Just unplug them, charge, and use on the next plane...onbce you have enough packs, you don't even need to field charger them...pre-charge them all, and fly them till they run out and go home. If you want different power levels, parallel or series up packs (fully charged of course to make sure discharge times are matched) and you can save on buying another pack. People on a tight budget have even been known to swap receivers, motors and ESC's between planes at the field. Unplug a few connections and unscrew two or three bolts, and away you go... Of course all this requires a change in the way of doing things and thinking. If you 'think glo' and do the sums you will never go electric. You have to 'think flight times and planes' and work out an overall budget for the type of flying you do...but in many cases, if you DO do this, you will find its not half so bad as the critics make out. How many planes do you take to the field anyway? > > | And you don't need a brushless motor to enjoy kithoum - the excess [quoted text clipped - 7 lines] > For a $20 8 cell NiCd pack it's not a big deal. But for a $900 battery > pack ... I don't see that at all. I run a $70 pack and a $18 gearbox on a $7 motor. All in $50 plane. Split amongst several models its not a silly thing to do. Look at the cost breakdown of a speed 400 plane. Kit cost $50 Glue, paint, covering, odd bits - $15 Motor $7 Gearbox $15 Prop $5 Receiver $50 4 x feather servos $80 Thats $222 already ... Now add ESC, at maybe $25, and we have a $250 plane without the battery. Since as I said the battery is costing (because its shared between three models at least only about $11 per plane), its a $262 plane at this point. Now if I drop the $25 ESC and add in a brushless+ESC at maybe $100 I am adding $75 to the plane cost. A 30% hike in cost. Besides which, that model is a scale jobby, and will potter around doing mild aerobatics for the best part of 40 minutes on the one charge. I simply don't need to spend $75 to extend that to one hour. Ive done the calculations over and over, and the way that makes sense is to buy lithium batteries, and share them between models. Motors I cosndeier more disposable, and cheaper than, servos. ONLY if I want the last ounce of performance will I bother forking out for a brushless. I mean, not every plane you have runs a tuned pipe high performance motor, does it? Stop thinking 'one plane, two packs' and start thinking 'oow packs, infinite planes' or whatever, and suddenly the cost benefit equations stand on their heads. > (For larger motors, doubling the power rating doesn't seem to double > the cost. A brushless motor setup with 0.40 performance doesn't cost [quoted text clipped - 4 lines] > That's my beef. If I could get Li-poly cells for like 20% of the > current cost, I'd go all electric tomorrow. The, > In the speed 400 sized cans, which are good enough for scale and modest > planes cost is less than $50 per motor/ESC/box combo Speaking of speed 400 motors, I've got one of those new Great Planes Douglas DC-3 Speed 400 EP Twin ARF ($159.99) on back order. It uses a Speed Control: Electronic with (BEC) battery eliminator circuitry and dual motor harness, and recommended battery pack is 9.6V 8 cell 1800mAh (AA cells). With Li-Po's at 3.7/7.4/11.1 volt, what Li-Po combination would you suggest for it? http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXFYW5 -- Jim L. https://sourceforge.net/projects/virtual-access/ Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 Not knowing how many amps the dual sp400 will draw, I'd use a 3S3P Kokam 1500mah pack(actually three of the 3S1P packs) That would be good to about 36A and almost triple the flight time. Just don't run it at full throttle for long or the motors could fry. Then again, depending on the sp400s they might be fine with higher voltage. PCPhill Don't ask how much I spent on batteries this morning. Really, don't ask...... ----- Original Message ----- From: "Jim Lilly" <a1pcfixer@comcast.net> Newsgroups: rec.models.rc.air Sent: Saturday, February 14, 2004 9:54 AM Subject: Re: Li Poly batteries, fantastic > The, > [quoted text clipped - 15 lines] > https://sourceforge.net/projects/virtual-access/ > Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 > The, > [quoted text clipped - 15 lines] > https://sourceforge.net/projects/virtual-access/ > Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 > Not knowing how many amps the dual sp400 will draw, I'd use a 3S3P Kokam > 1500mah pack(actually three of the 3S1P packs) That would be good to about > 36A and almost triple the flight time. Just don't run it at full throttle > for long or the motors could fry. Then again, depending on the sp400s they > might be fine with higher voltage. Unless they are race motors, they won't draw more than 10A apiece. Trouble is you can't gear EDF down, so they may get a little hot and bothered on 3sLIPO. The safe option is 2s2p, which will probably run at 15A or so. My choice would be Irate 1100 or thereabouts, but 3s2p of larger cells may be quite lively. Its a hard call. Its no aerobat, and may well run fine on the lighter 2s2p packs. > PCPhill > [quoted text clipped - 36 lines] >>suggest for it? >>http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXFYW5 Unless I'm confusing my acronyms, They're not EDF, DC3's were prop planes... I don't know if the lower voltage would be adequate for flight speed. PCPhill > Unless they are race motors, they won't draw more than 10A apiece. > Trouble is you can't gear EDF down, so they may get a little hot and [quoted text clipped - 6 lines] > Its a hard call. Its no aerobat, and may well run fine on the lighter > 2s2p packs. PCPhill, > I don't know if the lower voltage would be adequate for flight speed. I doubt it myself. -- Jim L. https://sourceforge.net/projects/virtual-access/ Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 TNP, > Unless they are race motors........... > Trouble is you can't gear EDF down The DC-3 never had EDF/Electric Ducted Fan engines & this Electrifly doesn't either. Not race 400's either. > The safe option is 2s2p As my original post stated, that DC-3 twin 400 requires 9.6volt, so a 2s2p @ 7.4volt probably wouldn't get it airborne. -- Jim L. https://sourceforge.net/projects/virtual-access/ Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 > TNP, > [quoted text clipped - 8 lines] > As my original post stated, that DC-3 twin 400 requires 9.6volt, so a > 2s2p @ 7.4volt probably wouldn't get it airborne. Lighter weight, so it might. If its geared props, go 3s2p and drop the prop diameter an inch roughly If its DD use same props, 3s2p and get 7.2v motors. > -- > > Jim L. > https://sourceforge.net/projects/virtual-access/ > Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 PCPhill, > Not knowing how many amps the dual sp400 will draw I've got an Astro Flight Super Whatt-Meter coming soon, and will be able to determine the DC-3's needs exactly. Still, I need some sort of battery pack as it comes with none. Might throw something NiMh for temp use to determine it's true needs. -- Jim L. https://sourceforge.net/projects/virtual-access/ Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 > PCPhill, > [quoted text clipped - 4 lines] > battery pack as it comes with none. Might throw something NiMh for temp > use to determine it's true needs. That's good. A mixture of theory and Whatmeter tests show that the 6v speed 400 actually produces less power as the current goes up above 10A. So don't prop or more than that. the 7.2v motor is happier at only 8A. If you have gears, you can get more out of a 6v 400 at 7-8A and 3s LIPO than 10A at 8 cell levels, because at the lower current is more eficient, and the extra volts gets the power input back. Props that are 'in the zone' on a 6v 400 on 3s LIPO are: 2.33:1 - use 7x5 3:1 - use 8x6 3.5:1 use 9x6 4:1 use 10x7 APC 'E' props tested. These will all produce decent thrust with adequate pitch speed - suitable for a model weighing up to about 40 oz (twin motors). For a small reduction in power and much better efficiency and cooler motors, throttle back, or use the next size smaller prop. Pack weight for 3s2p LIPO about 5oz, as compared with 9.6oz of 8x1700 NIMH cells. > -- > > Jim L. > https://sourceforge.net/projects/virtual-access/ > Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 The, > If you have gears Doesn't come that way, just DD. But if I ever went to a geared setup, it would need to be planetary as the twin 400's are mounted to the wing's LE & enclosed in cowling. That, or go brushless. > 6v 400 > > 7.2v motor Any easy way to determine which these 400's are? > Props that are 'in the zone' on a 6v 400 on 3s LIPO are: > > 2.33:1 - use 7x5 > 3:1 - use 8x6 > 3.5:1 use 9x6 > 4:1 use 10x7 Did you use Moto-Calc to get those figures? > suitable for a model weighing up to about 40 oz (twin motors). It's around 3 pounds! SPECS: Wingspan: 59.4" (1510mm) Wing Area: 393 sq in (25.3sq dm) Weight: 3lb (1360 kg) Wing Loading 17.6 oz/sq ft (53.7g/sq dm) Length: 37" (940mm) Airfoil: fully symmetrical, low wing -- Jim L. https://sourceforge.net/projects/virtual-access/ Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 > The, > [quoted text clipped - 3 lines] > it would need to be planetary as the twin 400's are mounted to the > wing's LE & enclosed in cowling. That, or go brushless. DD, for 3s LIPO use teh 7.2v motor. >>6v 400 >> >>7.2v motor >> > Any easy way to determine which these 400's are? If not marked, probably 6v motors. >>Props that are 'in the zone' on a 6v 400 on 3s LIPO are: >> [quoted text clipped - 4 lines] >> > Did you use Moto-Calc to get those figures? Partly, and partly cross checking with a selection of props and gearboxes. Heck, the weather has been **** and I had little better to do...:-) >>suitable for a model weighing up to about 40 oz (twin motors). >> [quoted text clipped - 6 lines] > Length: 37" (940mm) > Airfoil: fully symmetrical, low wing I seriously doubt it will fly successfully on two DD 400's then.. Well it WILL, but its a fairly high wing loading and not a great reserve of power. Don't eliminate gearboxes - the MPjet inner driven ones are very compact. Also, you can upgrade to 'long can' 400's - and provided the batteries can take the 30A or so the setup will draw, get about 50% more power. So, stick to stock motors an 1700 NiMh cells. get 7.2v motors and 3s2p LIPO gear existng motors and go 3s2p LIPO Depending on what suits best. > -- > > Jim L. > https://sourceforge.net/projects/virtual-access/ > Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 TNP, > Heck, the weather has been **** and I had little better to > do...:-) LOL, well understood. Several of us all-season fliers braved the elements Saturday & flew anyway. > I seriously doubt it will fly successfully on two DD 400's then.. Well > it WILL, Their video shows it doing fine. > Don't eliminate gearboxes - the MPjet inner driven ones are very compact. I'm beginning to think brushless will be the best choice in the long run. > So, stick to stock motors an 1700 NiMh cells. I'm going to start out with some 2000Mah NiMh's I've got & see where I need to upgrade after that. Provided I keep it in one piece.<g> > gear existng motors and go 3s2p LIPO Probably where I'll end up. Thanks for the great input! -- Jim L. https://sourceforge.net/projects/virtual-access/ Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 > PCPhill, > [quoted text clipped - 9 lines] > https://sourceforge.net/projects/virtual-access/ > Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 Reading what you gentlemen have said, I believe my point about the cost of electric flight is do-able now has been validified. I have two E3Ds. Cost of the first kit From Gary Wright was $100 + the cost of covering, glue, etc. about $50. The second is a copy and materials cost about the same as the kit. Now the AXI brushless, $97, ESP $107 and Li Poly 3S2P cost $100. So the first plane ready to fly costs about $450. This is a plane capable of verticals and 3D as the name implies. With Li Poly batteries, the flight times will be about 20 minutes, depending on throttle. Longer if the plane just loafs around. The second plane costing about the same will need only the same battery so it would cost about $350 RTF. I cut down the weight of my field box for glow from about 40 lbs, to about 2 lbs for electric. I just shut off my electric and go home. I do understand some flyers love to tinker with the gooey, oily mess but there's no beating turning on and turning off convenience of electrics. Remember for electric, the charger + power supply for the batteries cost about $200 or less. Is this not a one time cost? And how much for starter and battery, fuel pump, glow igniter, extra glow plugs, etc. cost for glow planes? Would someone do a cost analysis on a gas powered plane RTF for comparison? Sorry for being long winded, just enthused. Wan Wan, > Would someone do a cost analysis on a gas powered plane RTF for > comparison? Sure will! LXCXF442 Tower Hobbies Tower Trainer 40 RTF 42 72630 $269.99 {Complete RTF w/.46 eng, radio, and batteries} TH3755 Great Planes Standard ProGlo Starter w/Meter & Charger $19.99 TY5871 Great Planes Filling Station Can Fitting Set $4.69 LXK129 Great Planes Silicone Fuel Tubing Standard 3' $2.19 LXMA93 Hobbico Hand Crank Fuel Pump $12.99 LXK134 Great Planes Ultra Precision Fuel Filter $2.99 WS3710 Tower Hobbies Tower Power Starter 12V Deluxe $17.99 {Following 2 items ONLY included as they lowered the overall cost} DS80011 Tower Hobbies #1 Tower SS Club Pack-C $14.99 PC7125 $25 Promotional Discount $25.00- *FREE shipping* Purchased locally; 1 gal 10% glow fuel=$14.00 TOTAL=$334.82 w/discounts {Add avg of 30% at LHS} *NOT* included; 12v. Gel cell battery, power panel, spare props, etc {Windex, paper towels, and such needed for glows}. -- Jim L. https://sourceforge.net/projects/virtual-access/ Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1 | Reading what you gentlemen have said, I believe my point about the | cost of electric flight is do-able now has been validified. I don't think that anybody here was arguing otherwise. | I have two E3Ds. Cost of the first kit From Gary Wright was $100 + | the cost of covering, glue, etc. about $50. The second is a copy and | materials cost about the same as the kit. Now the AXI brushless, | $97, ESP $107 and Li Poly 3S2P cost $100. So the first plane ready | to fly costs about $450. Doesn't it have a radio and servos? I don't know what plane you've got, but I imagine it's a smaller plane. This is definately the range where electrics are reasonably priced. Try to get a 0.60 sized or larger plane with similar performance and see how much it costs -- it'll be quite a bit more. | I cut down the weight of my field box for glow from about 40 lbs, to | about 2 lbs for electric. I just shut off my electric and go home. I don't think anybody here needs to be sold on the advantages of electrics. | Remember for electric, the charger + power supply for the | batteries cost about $200 or less. Is this not a one time cost? At least until you find that you need to charge two batteries at once :) And you can do this much cheaper. GP Triton, $130. 110v -> 12v power supply, use an old AT computer power supply. Cost, free to $20. (For car use, you don't need any power supply.) | And how much for starter and battery, fuel pump, glow igniter, extra | glow plugs, etc. cost for glow planes? Well, much of that stuff is optional, especially for a smaller plane. And except for the glow plugs, it's a one time cost just like the charger. At least until it wears out ... For a small glow plane, a fuel bulb, glow ignitor and wood dowel (for starting) will get you going for about $20. | Would someone do a cost analysis on a gas powered plane RTF for | comparison? Well, I don't know what your plane is, I'm guessing it's 1/2A sized. So a good engine could be had for $50 or so, and you'll need a throttle servo, about $20 for a mini. $10 for a fuel tank. That, and some fuel replaces your entire $300 power chain. (Though there may be some additional cost as you'll need to make the plane fuel proof.) This thread wasn't originally about entry level. It was about the extreme cost (compared to glow) of larger electric planes. The entry level glow plane is about 0.40 sized, and the entry level electric is usually 1/2A (0.05 or so) sized. Cost is the primary reason that these sizes are entry level -- anything larger will cost more, but going smaller won't be much (or any) cheaper. SignatureDoug McLaren, dougmc@frenzy.com Lisa: Well, look at the wonders of the computer age now. Homer: Wonders, Lisa, or blunders? Lisa: I think that was implied by what I said. I agree the initial investment is high. I just spent a small fortune on Kokam 1500 batteries, 8 each 3s and 2s. The primary purpose is for a 1/4 scale with a 10S4P pack. But with the PCBs (series and parallel) they manufacture it will now be a simple matter for me to power anything from a speed 280 up to about a 90 glow equivalent. I haven't flown my glow models for a while now and I'm really considering selling all the engines. If anyone is interested I have a used, good running Saito 1.82 twin 4 Stroke headed to eBay soon.( Gotta pay for the batteries somehow) Make a reasonable offer..... PCPhill > | Reading what you gentlemen have said, I believe my point about the > | cost of electric flight is do-able now has been validified. [quoted text clipped - 8 lines] > > Doesn't it have a radio and servos? Yes but so do glow powered planes. > I don't know what plane you've got, but I imagine it's a smaller > plane. This is definately the range where electrics are reasonably > priced. Well, Doug, my plane has a 48" wing span and weighs about 56 oz before Li Poly reduced it to about 42 oz. I do have an advantage of lower weight over the heavier glow planes, if you could call it that. > Try to get a 0.60 sized or larger plane with similar performance and > see how much it costs -- it'll be quite a bit more. I have a friend who just finished a plane with a motor comparable in power to a .90 four stroke. Yes, his system did cost lots more and I can't account for it. Oh, yes his battery did cost about $345. And he does have a charger that could charge multiple battery packs. But how much does a .90 four stroke cost? > | I cut down the weight of my field box for glow from about 40 lbs, to > | about 2 lbs for electric. I just shut off my electric and go home. [quoted text clipped - 6 lines] > > At least until you find that you need to charge two batteries at once :) For me, you're right on that. I have to charge one battery at a time. But it's good for the whole afternoon after that charge. If only I have a charger like my friend's..... > And you can do this much cheaper. GP Triton, $130. 110v -> 12v power > supply, use an old AT computer power supply. Cost, free to $20. > (For car use, you don't need any power supply.) Now you tell me. I think I paid too much for the power supply for my Triton.. > | And how much for starter and battery, fuel pump, glow igniter, extra > | glow plugs, etc. cost for glow planes? > > Well, much of that stuff is optional, especially for a smaller plane. > And except for the glow plugs, it's a one time cost just like the > charger. At least until it wears out ... Agreed > For a small glow plane, a fuel bulb, glow ignitor and wood dowel (for > starting) will get you going for about $20. [quoted text clipped - 7 lines] > some fuel replaces your entire $300 power chain. (Though there may be > some additional cost as you'll need to make the plane fuel proof.) To do what my plane could, you'd need a .32 to .45 powered glow plane. Case in point, another flyer with a .40 OS could not keep up with it in a chase. Trouble at the time I had only about 7 miniutes flight time, but Li Poly changed that. My power train, motor, ESC, battery as presented befere, cost about $300. But, no fuel proofing, no tank, no need to buy fuel. But a good .32 engine such as the Webra costs about $109 rather than th $50 or so. But you do have me on the replacement cost. > This thread wasn't originally about entry level. It was about the > extreme cost (compared to glow) of larger electric planes. The entry > level glow plane is about 0.40 sized, and the entry level electric is > usually 1/2A (0.05 or so) sized. Cost is the primary reason that > these sizes are entry level -- anything larger will cost more, but > going smaller won't be much (or any) cheaper. Yes it was about the cost extremes from the smaller batteries to the nearly $900 batteries. But I know someone who made his own indoor plane of blue foam and flew it, total cost about $72. Now that's cheap. At the other extreme for electrics, the sky's the limit. I believe we're all waiting for prices of batteries to come down. Now I've heard there will be Li Poly batteries that will yield 20 C. I wonder if that will drive the "old" battery prices down? Where do you get all your quotes? "Discussion is good for the soul", Wan FINALLY someone who understands what I was saying. Thank you! > | Reading what you gentlemen have said, I believe my point about the > | cost of electric flight is do-able now has been validified. [quoted text clipped - 62 lines] > Homer: Wonders, Lisa, or blunders? > Lisa: I think that was implied by what I said. > > | 10S3P, 78amp (nominal) li-poly 7800mah 37 volt pack $873.60 > > [quoted text clipped - 62 lines] > current small cars would benefit from knocking a few ounds of teh wight > by replacing the lead acid cell. If the price was right... You both present points of view that are valid. WHEN the prices come down, not IF, we would all benefit. The costs of Li Poly batteries for larger aircraft seemed high indeed, But as the demand for them becomes high, then mass production will make for lower prices. Take the example of digital cameras. I bought a Nikon Coolpix 5000 for about $1,000. In less than 6 months an improved version was selling for around $700 (The Nikon Coolpix 5700, you may check it out). Most things electronic or otherwise kind of work that way price wise. This is my humble opinion. Wan From what I've been reading on E-Zone, 3 cell packs can easily get out of balance then cells need to be charged individually to get them equalized. Then there is real fire danger, charging takes an hour or more and you need a special charger. Three cells can fry a GWS 300C motor, two cells may not be high enough voltage for brushless motors. It gets expensive and complicated building and maintaining high amperage packs for large motors. For now, Li Polys are great for parkflyers and indoor models if handled properly. Gary > Hi, > [quoted text clipped - 18 lines] > > Wan > From what I've been reading on E-Zone, 3 cell packs can easily get out of > balance then cells need to be charged individually to get them equalized. That is only true if you really cane them. Otherwsie they stay pretty well balanced. If you must thrash big packs, check out suzannes pack balancer on the ezone. Its too heavy fort micro sized packs, but no great penalty for the big ones. > Then there is real fire danger, Its real, but its not common. More people lose fingers to glo props than get hurt, and so far the aorts that has happened is asomeone losing a car when they tossd a damaged pack in teh back,. COLKD have been a Nicad juts as easily. Ive seen cars burn out from shorts in their OWN electrics. A danger to be taken seriously, but no worse than any other. If you must charge the packs where youi can't see them,. make sure they are in something fireprrof. I wouldn't store glo fuel by an open fire in a plastic can either :-) > charging takes an hour or more and you need > a special charger. Wll charging NiMh takes an hour or more and you need a special charger. And you only get at best 5-10 minutes. Lipos might be esily 10 -20 minutes flight. I don't mind waiting an hour to recharge after three 7 minute flights. nd LIPOS don;t need to be peaked up beforre flying. You can charge a bunch at home, during the week, and fly em flat at the weekend. By the time ou have flattend the last one the firts will be ready to fly again anyway... > Three cells can fry a GWS 300C motor Only if you don't pull the prop size down to get the currentin safe limist >, two cells may not > be high enough voltage for brushless motors. That is all about propping and gearing the motors right for the packs. I am getting BETTER efficiency AND power by carefully adjusting gearing on cheap motors, by going up in voltage. > It gets expensive and > complicated building and maintaining high amperage packs for large motors. That I agree with. The big packs are exopenseive, need a bit mopre safety discipline, and a bit of looking after. Well if you havd forked out a few hundred dollars for a big 4 stroke, you would take accare of it too. > For now, Li Polys are great for parkflyers and indoor models if handled > properly. No, they are great for up to about 1/2 bhp (roughly .15-.25 equivalent). Beyond that it gets to >$100 for the packs, and they start to need special treatment if for no other reason than they are too expesnive to break! > Gary > [quoted text clipped - 20 lines] >> >>Wan Gee, I was caned mercilessly for even suggesting the same thing! No, they are great for up to about 1/2 bhp (roughly .15-.25 equivalent). Beyond that it gets to >$100 for the packs, and they start to need special treatment if for no other reason than they are too expesnive to break! > Gee, I was caned mercilessly for even suggesting the same thing! No, you were caned for saying that the entry fee was too high, somehow assuming that the only way to enter E-flight was at the 61 model size level. And also fo refusing to understand that packs and models are not |
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