Battery Charging - Overcharging

That was quick.

While I can see you point I think there is more to it.

1. Has not happened before and I have 2 of the batteries.
2. Nobody removes when the car battery plugs when it is charging?

An the smell. I have a double garage and it was pretty strong.

I know all about that smell. Happened to me when I was trying to resurrect an elderly Trojan 130Ah battery which had a high internal resistance and would not hold a decend charge.

I have a charger that is capable of delivering 40A.

So I connected the battery to that and wound the 'wick' up a little to about 15V (its a manual, constant voltage, charger).
The current and voltage was monitored and at that voltage a small current started flowing into the battery.

Went shopping then and upon coming back I could smell the battery from outside the closed garage. Opening the roller door revealed a VERY hot battery that was literally hissing acid spray all around it. I quickly switched the charger off and removed myself. It took absolutely ages for the battery to cool down sufficiently so I could take stock of the situation. I rekon I was very lucky that day, I did have the covers off the filling holes which saved my bacon. That Trojan has two large cover thingies which each expose 3 cell filling holes. There was not much liquid left in the battery.

When switching off I noticed the charger was actually putting the full 40A into the battery, whatever caused the initial high cell resistance obviously broke down, allowing all that current to flow.

Sadly, the battery still did not hold a decent charge after that treatment and has long since gone to the recyclers.
Klaus

Thanks v8.

The battery is fairly new. Only purchasesd Sept Last year so should be under warranty.

The charger is a 15ah 3 stage charger. I noted it went back to 'Bulk' Charge.

One question I have for other EO members is how do I determine if it is the battery which has failed or the charger?

Coolman, you ask; how do I determine if it is the battery which has failed or the charger?

First contact the charger supplier and advise them of your problem, then advise them if they believe it is working correctly you will then attach it to your cranking battery and will be looking for two new batteries & charger (from them) if it happens again :-(

You need to connect the charger to a known good battery and monitor current and voltage.

The voltage should slowly rise to 14.4 volts and hold at that, until the current reduces to 1/10th of the rated current - 1.2 amp for a 12 amp charger. Then the voltage should drop suddenly to 13.6 volts.

Mike

i.e

The voltage should slowly rise to 14.4 volts - Stage 1

and hold at that, until the current reduces to 1/10th of the rated current - 1.2 amp for a 12 amp charger. - Stage 2

Then the voltage should drop suddenly to 13.6 volts. Stage 3

Mike

"That smell" is both poisonous & very explosive, be careful!

It is a Smart Charger BC-012-15A.

I will have a look at the specs to see what it says about safety but on the weekend I will put it back and and see if a cell on the battery has shorted.

It will make me think twice about 'just leaving it' in future. It was bloody hot and smelly. I think the gas is Hydrogen so the chances of ignition are high. Don't fancy my garage and Paj going the same path as the Hindenberg.