LiPo lifespan?

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CRaSH - 29 May 2006 21:24 GMT

Wan just posted a LiPo question that has me wondering about the average user
and his/her experience with longevity on LiPo's.

My 1.6 year old Thunderpower 3S2P 4200mah started losing it's vigor after
about 200 cycles. It became painfully clear a few weeks ago when after
being used to three ~10 minute flights from a charge (I'm not a heavy
throttle/3D type :), my Pigi ended up 20' up a tree after power evaporated
on tuning final with a stiff cross wind on it's second fairly short
flight... Watt meter tests then showed the voltage dropping to 8V with full
throttle, even fresh of the charger. New replacement only drops to ~12V
same test..
Had a barely 6 month old 2200mah, 3S1P, Polyquest have one cell go south (it
has taps, the old TP doesn't) - so it's now a 2S1P, unfortunately I have
nothing that uses a 7.4V. A Poly 1350mah purchased the same time still
doing fine..
Have a couple of 1.8 yr old Kokam 1500mah that are still hanging in there
for light duty stuff, but their hi capacity discharge is a joke...

Cheers'n Beers.. [_])
Don

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A.T. - 30 May 2006 00:10 GMT

refer to "Battery care, Chargers & Power Supply."
at Alan's Hobby, Model & RC Web Links
http://homepages.ihug.co.nz/~atong/

sub section
Lipol batteries (Lithium Polymer) - Risks of failure and fire = high.

Complete Guide to Lithium Polymer Batteries and LiPo Failure Reports
Li-Pol Explosion - Video ***
Lipo fire tests you need to see - video X 2 ***
Lithium Polymer - FAQ & applications
Lithium Ion & Lithium Ion Polymer Safety and Instructions
Lithium Ion Polymer Applications
Lithium Polymer Batteries : LiPol FAQ
Tom's RC Electronics Gadgets and Projects - Lipol fire """
view the videos and read the test procedures and photographic / video
results

regards
Alan T.
Alan's Hobby, Model & RC Web Links
http://homepages.ihug.co.nz/~atong/
.................................................................

> Wan just posted a LiPo question that has me wondering about the average user
> and his/her experience with longevity on LiPo's.
[quoted text clipped - 16 lines]
> Cheers'n Beers.. [_])
> Don

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wan - 30 May 2006 00:31 GMT

Wow! Did you take a look at the information given in Alan's post? I
don't know where to begin.

Thanks, Alan. I will take some time and do a bit of reading.

Wan

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CRaSH - 30 May 2006 01:19 GMT

> Wow! Did you take a look at the information given in Alan's post? I
> don't know where to begin.

A absolute treasure trove of articles. Only thing I saw relevant was a
reference in the LiIon section which suggested a cycle life of 500, and a
3-5 yr lifespan was expected. I assume this is probably applicable to pc's,
cell phones, and the like, but still doesn't tell me what to expect from our
applications with LiPo's, which I believe may put a more "life threatening"
factor into the equation - especially the crashes....... d:->))

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The Natural Philosopher - 30 May 2006 10:16 GMT

> Wan just posted a LiPo question that has me wondering about the average user
> and his/her experience with longevity on LiPo's.
[quoted text clipped - 16 lines]
> Cheers'n Beers.. [_])
> Don

This seems to be fairly standard..200 cycles - especially when
discharged hard or deep - and the battery starts to behave as if it had
about half the capacity.

Most of us who care are working our cells at 70% derating (current *and*
capacity) to see if this improves matters.

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Model Forum / Radio Controlled / Air Models / May 2006

LiPo lifespan?