Ok, so in my old 97 Sunfire I had a Optima Red Top in there. It was in an accident and the car sat around for a few weeks before I decided to scrap it. The alarm drained the battery - no biggie, I have a battery charger right? This is the charger I have Motomaster Eliminator Charger

So I charged it on the fast charge option (6A) and after a while I started to hear a sizzling noise coming from the battery, I wasn't sure what the deal was - if it was venting or if it was heating to the point it was boiling or what not. So I unplugged it, let it sit for a day, and then decided to put the charger back on on slow charge (2A), and after a little while it did the same thing again. I decided that it was at 11V and that was good enough. It sat for a few weeks, unplugged and now it is in my new sunfire and I have had no problems yet.

But, what is the deal with the sizzling? Normal? Safe? Gonna blow up? I was thinking maybe it was over charging, but the battery charger is like a smart charger with a minder on it, so it shouldn't overcharge. Any explanations?

The sizzling is a normal trait from the gasses being emitted from the charging process.
Gas is released through the vent holes so that it doesn't blow up the battery.
This is why when you relocate the batter to your trunk and put said battery in the sealed box you need to have a ventilation tube to the outside.
Normal process so don't worry about it.



Edited 1 time(s). Last edited Tuesday, November 09, 2010 5:08 PM

Misnblu.com
Newbie member since 1999
Thank you Dave and JBO!

At first I was worried about it blowing up in my face, but then I did some research. So we established it is safe, but what about anything else, is it indicative of something? Perhaps, a failing battery? Or a faulty charger that was overcharging?

I am pretty positive that all the Optima Batteries are dry-cell technology. They dont utilize acid they use gel. I may be wrong you should look into this when you get a chance. In which case you need a special charger to charge them, I have one at home it has settings pending on what type of battery it is in addition to amp size (2a,10a,20a). I don't own a yellow top battery anymore its been years so this information is fuzzy, sorry.

All batteries have to breathe whether it's dry cell, gel cell, or standard liquid acid battery.
You'll probably notice tiny holes at the top of the batteries for the ventilation to occur so it's a normal process.
As the battery becomes fully charged, there may be a boiling process that you're hearing but it's not really boiling. It's just the way it sounds as the battery emits gas from the charging.

Btw, even though it's a gel formulation in the battery, it's still acid.
Make sure that your charger is one that reduces the charge as it charges the battery, this way you don't over charge the battery and can keep it on the charger for longer periods of time. If you're continually ramming a said amount of amperage into the battery, that battery will over charge and probably ruin a cell or two, usually those closest to the posts as this where the voltage/ amps enter and exit the battery.

Good luck.



Misnblu.com
Newbie member since 1999
Thank you Dave and JBO!

Its a charger with 3 settings, fast 6amp, slow 4amp, and a 2amp setting. But it ramps it down as the battery nears completion. Once the battery is fully charged it enters a floating/minding mode to just give it some small voltage when it needs to stay optimally charged. The red top does have this sort of vent on the top of the battery. 2 actually - they`re holes with a sort of filter on them. Red Tops are gel - but I don't need a ''special'' charger for them. Maybe the old ones don't work with new tech, but its a new model battery charger and it suitable for all chemistries/models.

thanks for the help guys. I got lucky - a week after I bought it for $59.99 it went on sale for $29.99, so I got reimbursed. Pretty sweet charger for $30.

=D