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

[Rick Abbott]

I have 3 of these SLA's that also came out of UPS service in the telecomm
industry. They came equipped with mini charge controllers (one on each
battery) that does a fine job of current limiting. They start off allowing
higher current and slowly taper off to trickle charging. I had meters on the
whole affair for the first 2 charges and have never needed to
measure/monitor since then. Maybe I am too trusting, but all appears well
for several years now.

  
 
Thanks,

Rick Abbott-WX9M
Emergency Coordinator
Portage County
Wisconsin ARES/RACES
wx9m at charter.net



-----Original Message-----
From: ares-races-bounces at mailman.qth.net
[mailto:ares-races-bounces at mailman.qth.net] On Behalf Of Mike (KA5CVH) Urich
Sent: Monday, May 02, 2005 12:09 PM
To: ARES-RACES
Subject: Re: [Ares-races] RE: ARES-RACES - Batteries

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
&quot;Don't it always seem to go that you don't know what you've got...till
it's gone.&quot; from Big Yellow Taxi (Joni Mitchell) but also true about
QSL.NET if more users don't open their wallets and help financially. Please
contribute TODAY !!
_______________________________________________
ARES-RACES mailing list
ARES-RACES at mailman.qth.net
http://mailman.qth.net/mailman/listinfo/ares-races