Revive Abused Battery

UPDATE: I placed the battery on the manual charger at the 12V/2A setting for about 45 minutes. Amperage slowly crept up to about 18A, according to the analog ammeter on the charger, while my DMM showed a voltage of 9.3V between the alligator clamps. I had the caps off, and only two cells were visibly bubbling, but I could smell the acid. The battery was getting warm, and I noticed it was very warm on the sides of the battery near the positive terminal around the top of the battery. I am trying to learn about batteries, so I'd appreciate your analysis of the situation:

Questions:

1. Why 9.3V/18A? Why isn't the current limited to 2A, as per the manual charger setting? How would you expect or hope amperage and voltage to behave in this situation?

2. Why bubbling in only 2 cells? Is any bubbling bad during normal charging? Would a healthy battery avoid all bubbling except while being equalized at high voltage?

3. Is the amount of heating normal for charging a battery starting from the 0.7V initial state?

4. Shall I proceed with charging at the 12V/2A setting while monitoring heat level, and only stop if it gets quite hot (rather than very warm, as it already did)?
 
Bubbling happens when a cell is charging at 2.5 volts or more and hydrogen and oxygen are being released. The fact that you've got two bubbling cells and only 9.3v tells me you've got some bad cells and are unlikely to revive it. A battery should never get hot with only a 2 amp charger, as well. I would trade it in.

And for goodness sake, if you want to keep charging it, please wear safety glasses and a hose ready to douse yourself when battery acid goes everywhere. 😲
 
You need to take it with you to get the core charge back in one trip. Get rid of it. I just bought another Value battery from WM. $55, but store tag said $57 so maybe it’s going up again. I have been checking online, out of stock always, none in area. I go to store and they had four in my size in the rack.
 
You need to take it with you to get the core charge back in one trip.

Do you think I would have difficulty exchanging it if I weren't purchasing a new battery in the same trip, you mean?

Thanks ripcord and Job. I realize the battery is toast, but I was hoping someone could explain whats going on with it, given the conditions I described in post #21. Particularly my first question:

Why did the battery end up charging at 9.3V/18A after 45 minutes on the 12V/2A setting? Why wasn't the current limited to 2A, as per the manual charger setting? How would you expect or hope amperage and voltage to behave in this situation?
 
The battery has an internal short circuit which is holding the voltage of a cell to zero instead of the nominal 2.4 volts.

As expected when there is a short circuit, current increased.

The old fashioned manual chargers that are simply a transformer and diodes have no provision to regulate output current. They are designed to supply their rated current to a good battery.
 
And for goodness sake, if you want to keep charging it, please wear safety glasses and a hose ready to douse yourself when battery acid goes everywhere. 😲
Thank you for saying this because I was going to.

If OP keeps this up, best case scenario is he'll drip acid on his pants and be out $30, the price of a new battery.

Worst, something blows up in his face and blinds him.

This thing's a hornet's nest, quit poking it.
 
Thank you for saying this because I was going to.

If OP keeps this up, best case scenario is he'll drip acid on his pants and be out $30, the price of a new battery.

Worst, something blows up in his face and blinds him.

This thing's a hornet's nest, quit poking it.
Even at $100, my face/eyesight is worth more
Disconnect, let it cool down overnight, and trade that bomb in on something new
 
Still alive and sighted! Thanks everyone, especially for the safety recommendations. I always wear eye protection when working with automotive batteries and encourage everyone to do the same. Appreciate the concerns and safety tips. No more charging of this battery--rest easy!
 
Still alive and sighted! Thanks everyone, especially for the safety recommendations. I always wear eye protection when working with automotive batteries and encourage everyone to do the same. Appreciate the concerns and safety tips. No more charging of this battery--rest easy!

Did it become a core for a new one?
 
I'm glad you didn't take an acid bath, and I appreciate your work and reporting. I wonder too about your questions, particularly a charger flowing more amps than it's rated at. Hmm... all I can figure is that rating is bogus. This is how we learn so we can apply knowledge in the future for benefit.
 
I'm glad you didn't take an acid bath, and I appreciate your work and reporting. I wonder too about your questions, particularly a charger flowing more amps than it's rated at. Hmm... all I can figure is that rating is bogus. This is how we learn so we can apply knowledge in the future for benefit.

I assume the battery has an internal short, as someone mentioned upthread. Apparently manual chargers don't necessarily have capability to limit current. The 12V/2A setting only provides the nominal current to a good battery, I guess. Perhaps someone else has more info.
 
A manual charger and the battery that it is trying to charge can be looked at as a Thevenin circuit, which is one of the first topics in electrical engineering. You can search for Thevenin to learn more.
 
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