| Author |
Message |
Henry Draper (12.82.132.138)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, December 29, 2002 - 5:43 pm: | |
Hi Folks,
I have a battery bank comprised of nine, group 27, gel cell batteries. I want to test the bank.
I bought a battery tester from Harbor Freight (thanks to those who made recommendations not so long ago--especially Geoff) and now I'm trying to avoid taking loose all those connectors!!
So my lazy question is: can I test the bank, then if there's a problem, disconnect and test individual batteries? Would a weak battery show up if I left them all connected? Or should I just bite the bullet, go ahead and disconnect them, and test all nine individually?
Thanks.
Henry Draper
1964 Eagle
Edmonds, WA
P.S. I'm jealous of all you folks going to Bussin' 2003! Wish I could be there with you. Have a good time, learn lots, and be safe! |
Jim Stacy (32.101.44.6)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, December 29, 2002 - 8:16 pm: | |
Henry,
If you have 9 batteries, I assume the are all in parallel. The only sure way is to test them individually. Remember, you need only disconnect one terminal from each battery to test it. That's only half the work.
Yup, wish I was going too, but 2700 mile round trip from Brownsville is a long way. Maybe they'll hold it in April one year and we can catch it on the way home. Thanks, Jack for all your work in organizing Bussin'.
Jim Stacy |
Henry R. Bergman, Jr. (Henryofcj) (65.194.145.47)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, December 29, 2002 - 9:04 pm: | |
Hey Henry, when we had two sets of 10 Nicad 125 AH batteries we individually tested them each year using a length of 16 gage wire as a direct short over an 8 hr period, then taking hour voltage readings.
But...the Nicads were 1.25 volts each, (not 12 VDC) sooossss I do not know how long the wires would be. Ohms law I quess. Anyway, it was fun and took about a day and recorded each cell. Good luck. |
Henry R. Bergman, Jr. (Henryofcj) (65.194.145.38)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 04, 2003 - 10:21 pm: | |
Hey Henry:
I finally remembered that the length of 16 gage wired alluded to earlier was about (I think!) 26 feet, 9 inches long each. Could be wrong too.
We did not unhook the interconnecting cables. Too lazy I guess. After the batteries were fully charged using the PV panels we let them set about 3 days...
Too remove the surface charge. Then we simply hooked up the length of wire to each cell and took individual voltage readings using a Fluke meter once every hour for 8 hours...
Or until the voltage got down to 1.00 volts per cell (10 1.25 vdc cells make up on string totaling 12.0 vdc nomimal)
The wire simply acted as a resister absorbing the energy from the batterys and turned it to into heat. The wire only got warm to the touch.
The 16 gage wired was sized to represent an 8 hour discharge rate. This would equal 120 amp hours divided by 8 hrs. or about 15.5 amps per hour.
I do not know if this would work with 12 vdc cells. Much higher voltage which MAY mean too m
uch heat generated. Good luck. Henry of CJ |
Jim Stacy (32.101.44.252)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, January 05, 2003 - 8:27 pm: | |
Batteries wired in series (as the 1.25 ni-cads) can be tested individually without disconnecting them from the system, batteries wired in parallel cannot. FWIW
Jim Stacy |
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