Darn it! I probably fried $3,000 worth of batteries

belfert · August 23, 2018, 05:53:54 AM

I have six fairly large AGM batteries for my house bank that I got free, but would cost $3,000 to replace.

My DC breaker for inverter/charger failed so batteries not charging. The batteries had plenty of voltage after my May trip, but now they are down to 14 volts on a 24 volt bank. I am not sure if I can even resurrect them, but they will certainly be hurt if they come back.

I will probably just go with two 8D AGM batteries if I need new ones as I can?t afford six new batteries like I have now. My amp hours will g down, but it is what it is.

buswarrior · August 23, 2018, 06:45:59 AM

I would break the bank apart and work on each battery alone.

Some of 'em might come back.

Happy coaching!
Buswarrior

neoneddy · August 23, 2018, 07:18:04 AM

At least they are not flat. I think there is hope yet.

Charge each one and see what happens.

Jon · August 23, 2018, 11:29:08 AM

You might want to try an equalization charge. The battery manufacturer likely has a battery owner's manual that calls for the voltage and length of time for the charge.

Usually free batteries are worth every cent you paid for them so if that doesn't work and the batteries are toast at least you tried.

bevans6 · August 23, 2018, 11:43:46 AM

AGM may well be different, but I've brought back batteries that were at 3v (out of 12). You may need to start with an old fashioned transformer charger, a smart charger may not start charging that low.

belfert · August 23, 2018, 12:24:26 PM

Quote from: Jon on August 23, 2018, 11:29:08 AM
You might want to try an equalization charge. The battery manufacturer likely has a battery owner's manual that calls for the voltage and length of time for the charge.

Usually free batteries are worth every cent you paid for them so if that doesn't work and the batteries are toast at least you tried.

I thought equalization can blow up AGM batteries?

The free batteries I got are only a few years old, and were on a float charge all that time. The batteries were a backup for a telecom cabinet at work that never lost power. The telecom provider was removing the cabinet and they were going to scrap the batteries so I asked if I could have them. The batteries were in excellent condition and fully charged when I got them.

It was me who destroyed the batteries through not replacing the breaker right away. They worked great on my first trip out in May.

TomC · August 23, 2018, 04:48:20 PM

On AGM, 14.1 volts on a 12v battery is the highest voltage you should go. They should come back. Good Luck, TomC

eagle19952 · August 23, 2018, 09:09:11 PM

Quote from: belfert on August 23, 2018, 12:24:26 PM
I thought equalization can blow up AGM batteries?

Max charge on an AGM is 13.8v I am told be DEKA and Xantrex.

OK, 14v but NOT for days...not even hours I am told.

The manufacturer is a better source of what to's and not to's than the internet.

TomC · August 23, 2018, 09:27:09 PM

Lifeline is 14.1 volts till full charge then down to 13.2 for float.

Jon · August 24, 2018, 04:05:17 AM

I am aware of the knowledge here, but those who opine about max voltage should read a typical battery owner's manual.

Page 21 of the link describes the "conditioning" or "equalization" charge for AGM batteries.

http://lifelinebatteries.com/wp-content/uploads/2015/12/6-0101-Rev-E-Lifeline-Technical-Manual.pdf

luvrbus · August 24, 2018, 04:52:25 AM

Use your battery manufactures instructions it varies and pay close attention to the heat chart and charging voltage a AGM when charging it will go to hell in a basket in hurry,I have 6-8D's to back that up

bevans6 · August 24, 2018, 11:18:33 AM

Interesting reading that manual PDF on charging AGM's, busts some myths for me and confirms some things I've been doing for years.

eagle19952 · August 24, 2018, 07:38:51 PM

The OP didn't say Lifeline...
I own DEKA batteries and Xantrex inverter charger.
both told me that equalization was a very bad idea.
So. I programmed my remote so it doesn't happen.
My batteries are still going strong almost 8 years now.
YRMV.

eagle19952 · August 24, 2018, 07:44:23 PM

Quote from: Jon on August 24, 2018, 04:05:17 AM
I am aware of the knowledge here, but those who opine about max voltage should read a typical battery owner's manual.

Page 21 of the link describes the "conditioning" or "equalization" charge for AGM batteries.

http://lifelinebatteries.com/wp-content/uploads/2015/12/6-0101-Rev-E-Lifeline-Technical-Manual.pdf

it also says that it should only be attempted by trained technicians

luvrbus · August 25, 2018, 05:00:38 AM

LOL guys you can thank me for Revision E in 2017 in the Lifeline instructions

,I always said it was BS the way some people told you how you mount AGM batteries