[Ares-races] RE: ARES-RACES - Batteries

[Mike (KA5CVH) Urich]

On 5/2/05, Dave Colter <dbcolter at adelphia.net> wrote:

> Charging is easy. Just feed them about 14.5 volts. Any more, and you'll
> charge them too fast. 

Mike wrote

I too was able to pick up some "large" SLA batteries that were taken
out of UPS service because of age.   I agree and disagree with you
conclusions.  Yes you need about 13.8-14.2 vdc to charge them but
that's not what will over charge them.  You need to limit the current
as well.  I use an old 300mw wall wart to charge all mine.   I have
ran the batteries down to about 9 volts and then charged them as a
test.  It takes quite a while <2-3 days> with the wall wart but I've
never observed in rise in battery case temperature <evidence of
overcharging>.
The "near dead" batteries pull the output voltage of the wall wart
down to about 1/2 volt above the batteries static voltage <measued at
the terminals>.  When they are charging I keep an old voltage meter on
them and when I see the voltage up to about 12.5-13 vdc I take the
charger off.

-- 
Mike Urich, KA5CVH
http://ka5cvh.com

Character is how you treat people who can offer you nothing in return