Help - AGM battery won't charge

[SaltyGirl]

The battery shows a 12.1 volt charge, but when I hook up the battery charger it says the battery is sulfated. I can't make sense of it. Can a battery be failed if it still shows a 12.1 voltage? I don't think I wan it to get below that, do I?

What should I try next? The West Marine 31T battery is only a couple of years old and shouldn't be failing yet. Help.

[svlamorocha]

Originally Posted by SaltyGirl

The battery shows a 12.1 volt charge, but when I hook up the battery charger it says the battery is sulfated. I can't make sense of it. Can a battery be failed if it still shows a 12.1 voltage? I don't think I wan it to get below that, do I?

What should I try next? The West Marine 31T battery is only a couple of years old and shouldn't be failing yet. Help.

Many batteries fail before two years because of the way they have been used or charged. It will help if you provide more details about your charger, how have you used the battery, etc.
C

[Nicholson58]

There is always a possibility of infant mortality where batteries are concerned. We have 10 AGM Lifeline batteries - 640 AH. So far no issues. Balmar charge controller on a 1.5 kw alternator & Xantrex 2 kw dockside. Perhaps you can research the maker's or other AGM maker's site for help in diagnosing problems. Lifeline's site may offer some help. Try also Rolls. My Lifelines came with a book describing all necessary voltages. It was useful in programming the chargers.

Lifeline will ship direct to a UPS destination. Price was 1/2 retail & 1/4 We$t.

[SaltyGirl]

Thanks. I have been looking online for the right info. The battery has been "abused" because the echo charger broke and I started using a little AC charger. I tried to remember to charge before it got below 12 volts, but probably didn't do that completely.

The little AC charger is reporting an error that says battery is sulfated and can't be charged. The thing that has me confused is that it is at 12.1 volts now. Can a battery be "dead" , as in no hope of bringing to full charge, if the voltage is showing 12.1? I guess I can just use the Barry until it is at lower voltage, but I wasn't sure that was smart to do. It's a $300 (or close I think) West Marine Group 31....

[mbianka]

Originally Posted by SaltyGirl

The battery shows a 12.1 volt charge, but when I hook up the battery charger it says the battery is sulfated. I can't make sense of it. Can a battery be failed if it still shows a 12.1 voltage? I don't think I wan it to get below that, do I?

What should I try next? The West Marine 31T battery is only a couple of years old and shouldn't be failing yet. Help.

I would not give up on it yet. I had a problem with one 12 volt AGM battery of a 48 volt string (four 12 volts in series).
THE BIANKA LOG BLOG: BATTERY INVESTIGATION PART 2: MORE BATTERY TROUBLE SHOOTING OF A 48 VOLT STRING
It was only two or three years old but because I had a small parasitic load on it for a battery monitor to collect data on the battery string over the winter it failed to charge come the spring. At first the charger timed out with errors like it was sulfated. But, by continually trying to recharge the battery it slowly came back and is still powering my propulsion system today. You might want to try another portable charger (make sure it has a setting for AGM batteries) and alternate between chargers and see if it improves over several charge cycles. Mine did and is still working fine today.

[svlamorocha]

Is this a house or engine battery?

Originally Posted by SaltyGirl

The little AC charger is reporting an error that says battery is sulfated and can't be charged.

What make/model of charger is the "little AC charger"?

Originally Posted by SaltyGirl

The thing that has me confused is that it is at 12.1 volts now. Can a battery be "dead" , as in no hope of bringing to full charge, if the voltage is showing 12.1?

A dead battery can show 12.1V if there is little or no load placed on it. That said, before drawing any conclusions about the battery you need to make sure you are giving it all the charge it will take.

Do you have an engine you can run to charge from the alternator? If so run the engine at 2000 rpm or more and measure/record voltage across terminals every 15 minutes until it stabilizes (to a tenth of a volt), then report the history of voltage values you got.

Do you have a clamp DC ammeter? If so once the voltage flattens out measure the current (amps) in one of the battery cables every 15 minutes and keep charging until the amps drop to 1/30th of the rated Ah capacity.

Then you will be able to say that the battery has all the charge it will take.

Once you get to this point we can worry about the following steps.

Originally Posted by SaltyGirl

I guess I can just use the Barry until it is at lower voltage, but I wasn't sure that was smart to do.

What is "the Barry unit"?

Cheers

C

[skipmac]

Originally Posted by SaltyGirl

Thanks. I have been looking online for the right info. The battery has been "abused" because the echo charger broke and I started using a little AC charger. I tried to remember to charge before it got below 12 volts, but probably didn't do that completely.

General rule of thumb, AGM batteries are much less tolerant of abuse than other types. One very good reason to stick with plain old FLA (flooded lead acid) batteries. AGMs like to stay charged up. Can tolerate some discharging to a low voltage but should be recharged back to full charge asap or they can die an early death.

Originally Posted by SaltyGirl

Can a battery be "dead" , as in no hope of bringing to full charge, if the voltage is showing 12.1?

In general just looking at battery voltage by itself is a very poor indicator of anything including battery health, state of charge, etc. Voltage can be useful if you include a lot of other factors but requires more knowledge of how batteries and charging works to make any sense.

Originally Posted by SaltyGirl

It's a $300 (or close I think) West Marine Group 31....

Another good reason to stick with cheaper, standard FLA batteries. Something screws up and you end up with a dead battery it's a lot less painful to replace than an AGM.

But, as mentioned. Your battery might be salvageable. As soon as possible hook it up to a good, smart, multistage charger and fully charge it.

[SaltyGirl]

Thanks...before I give up I am going to hook up an echo charger I just bought. I am connecting it to the house bank which is currently on maintain at 14 volts +. I'll report back in a few hours. Maybe the AC charger (black & Decker, Vector Smart) has a problem. It is giving me error codes f02-f03....those mean "your battery is shot" I think.

Anyway...let me hook up this new charger and report back. Thanks for all of the help!

[mbianka]

Originally Posted by SaltyGirl

Thanks...before I give up I am going to hook up an echo charger I just bought. I am connecting it to the house bank which is currently on maintain at 14 volts +. I'll report back in a few hours. Maybe the AC charger (black & Decker, Vector Smart) has a problem. It is giving me error codes f02-f03....those mean "your battery is shot" I think.

Anyway...let me hook up this new charger and report back. Thanks for all of the help!

We are still waiting for that report.