Overcharged SLAs & damage?

[dirtdad]

I hate to even admit this here, but it was interesting and I have questions, so here goes.

I have 36V and 48V 3 stage battery chargers at my refueling station in the garage. I accidentally plugged by 36V SLA pack into a 48V charger. Hours later I smell hot plastic in the garage and figure it out and disconnect.

OBVIOUSLY this is to be avoided, please, no lectures on that.

But 2 things. What damage does that do to the batteries, aside from possibly melting them, which it did not. I could have fried eggs, tho.

Another thing. It did manage to pump the voltage of the batteries beyond their normal rating by a few volts according to my trusty Cycle Analyst - probably at great expense. What is the chemistry behind such an overcharge?

 

[Ypedal]

was it a 36v on a 48v charger or the other way around ? lol..

SLA is rather tough like that.. i'd be worried about the charger tho !

 

[Lessss]

If you overcharged the batteries then you cooked them. They bolied off some water and chemicals. More electrolyte added to the batteries would fix them up. The real question is there any physical damage to teh battery - puffing - damaged vents that won't close etc.

 

[safe]

From what I've been able to understand about it there are two chemical reactions that take place. There is an oxidation reaction and a sulfation reaction. The oxidation occurs on the charging side and the sulfation on the discharge side.

Desulfation involves overcharging or overamping for short periods of time to shake off the sulfation by compensating with the oxidation process. The only problem is heat and that corrodes the plates and shortens the life.

Pulse techniques use high voltage and current for short bursts to break up the sulfation but then allow rest periods in between to let the heat go down.

One thing is for sure... you won't need to desulfate for a while. :lol: