TIP: Click on subject to list as thread! ANSI
echo: tech
to: Tom Walker
from: mark lewis
date: 2003-04-24 01:49:38
subject: batteries

->> i've several 12volt, 11Ah batteries here that i'm wanting
->> to charge and load test... can i charge them with a standard
->> car battery charger? what settings should i use?

 TW> NO they are too small for charging on an Automobile Unit. Use
 TW> a motorcycle battery charger.

even the 2amp charge is too much? i have a charger that has three amp
settings for charging with... 2, 10 and 50 IIRC... the 50 is only for
starting boost and only good for about 30 seconds...

->> what's the best way to load test them to see if they are still
->> good?

 TW> Fully charge them and then put a 1 or 2 amp load and measure
 TW> how long before the terminal voltage drops below 10 volts.
 TW> As an example 1 amp for 10 hours would be 10 Ah. That would
 TW> indicete a very good battery. Iusualy think of replacing
 TW> non-critical batteries when the Ah is about 1/2 of the
 TW> Battery rating.

hummm... how'm i gonna determine a 1 or 2 amp load to put on them? someone
else was telling me that maybe finding a 12volt light bulb of some wattage
would work...

->> what does the 11Ah (Amp hours) really signify?

 TW> As stated about a rating of time vs Discharge current. With
 TW> smaller batteries ususaly discharging at 1/10 the Ah rating.
 TW> Whicy by the way is a good measure of a safe charging
 TW> current. Thus your 11 Ah battereis should be charges at
 TW> approx 1.1 Amps.

so the 2amp charge circut on my charger would be ok, then?

we've also got a wallwart charger for some batteries... output is
15vdc{at}100ma IIRC... i'll have to take another look at the battery to see if
i can determine its characteristics...

if the units i have here are all good and i can get them all up and wired,
it would appear that in just "spare" batteries, i have 12vdc 85Ah
or so capability... that should give me some decent uptime... i think that
tomorrow i'll make me some buss bars and solder some connector wires for
hooking to the batteries i currently have...

)\/(ark

* Origin: (1:3634/12)
SEEN-BY: 633/267 270
@PATH: 3634/12 106/2000 633/267

SOURCE: echomail via fidonet.ozzmosis.com

Email questions or comments to sysop@ipingthereforeiam.com
All parts of this website painstakingly hand-crafted in the U.S.A.!
IPTIA BBS/MUD/Terminal/Game Server List, © 2025 IPTIA Consulting™.