Charging NiMh with a transformer power supply

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

computer_prog@hotmail.com - 17 Feb 2005 17:53 GMT

A while back I built an adjustable power supply with a 12V 1.2A power
supply, a full wave bridge rectifier, and an LM117 adjustable
regulator. I was thinking about using this power supply to quick
charge a small 5-cell 6V NiMH battery pack I use in a R/C car.

If I connect the battery pack to my adjustable supply (set @ 6V) what
current will the power supply put out? Will the power supply put out
the 1.2A rating of the transformer? I do plan to carefully time the
charge so that I do not overcharge the pack.

Reply to this Message

Jack Conley - 18 Feb 2005 03:26 GMT

hmmmm, not too sure about the power out put but i do know this. for some
reason (unkown to me) you can not charge nimh batteries with a nicad
charger. even if the charge rate is the same. i wouldn't really venture to
make your own charger when you can get a simple wall charger for 6v nimh
from ofna for $7 or so.

>A while back I built an adjustable power supply with a 12V 1.2A power
> supply, a full wave bridge rectifier, and an LM117 adjustable
[quoted text clipped - 5 lines]
> the 1.2A rating of the transformer? I do plan to carefully time the
> charge so that I do not overcharge the pack.

Reply to this Message

Nithog - 18 Feb 2005 12:40 GMT

I use old NiCad chargers to charge mine nimh.
But I use a temp probe on the pack and go by that.
If you Google batteries, you find many charts for charging with voltage,
current, and temp.
It's not perfect and you have to baby-sit the pack, but it works.

> hmmmm, not too sure about the power out put but i do know this. for some
> reason (unkown to me) you can not charge nimh batteries with a nicad
[quoted text clipped - 11 lines]
>> the 1.2A rating of the transformer? I do plan to carefully time the
>> charge so that I do not overcharge the pack.

Reply to this Message

Model Forum / Radio Controlled / Land Models / February 2005

Charging NiMh with a transformer power supply