The other day I decided it was time to fire the ol' girl up after 10 months of service in the mothball fleet. Of course the battery is dead so I put it on the charger overnight not thinking anything of it. I have heard horror stroies of the Optima batteries, but I have never had any problems with them. Anyway, I charged it overnight and got in it the next morning to start it (after removing the battery charger of course). She roared to life and sounded great. I raised the hood to check for leaks and noises. I turned around to have a quick smoke while everything came up to temperature when I noticed a whiff of smoke pass by my head. I hadn't lit a cigarette yet so I was wondering where the smoke was coming from. I turned around and the battery was in flames and had swelled up to completely fill the battery compartment I jumped in the car and shut it down as quickly as I could, grabbed the fire extinguisher and went to work. After the smoke cleared I started checking for damage. Suprisingly, nothing was damaged except the battery. Even the battery cables were OK. However, the battery was so swelled that I couldn't get it out of the compartment. I let it cool down for about 2 hours and it finally shrank enough to pull it out. I took it to the auto parts store and told them my story. Hard to believe, but the mass in front of him that was once an Optima battery backed my story up. He wanted to replace it with another one, but I said "lead-acid please". I will never own another Optima battery. They are great if you never need to charge them, but if you do please pull it out of the car just in case. I got lucky and there was no damage, but I would have went inside the house I could have been playing "taps" at the junkyard instead of writing this story. Garry

 

Any ideas as to why and how it happened?

Bad design?
Direct short with cruise mount?
Over charged?

 

No direct shorts that I could see and the car fired right back up with the lead-acid battery and is still running great. Maybe I did overcharge it, but the charger is supposed to keep that from happening I thought. There is something about gel-cell batteries that makes them difficult to charge.

 

How did you charge it? What was the setting that the charger was on? Does your charger even have one of those setting switches? If you used anything other than the maintenace free setting which takes 3-4 times the amount of time to charge the battery you basically cooked the OPTIMA battery. Especially if you used one of those old school $19.95 chargers. If thats the case Yikes!! your lucky it didnt explode in the garage. Glad to hear your ok and the car is ok as well. Just a guess here but it sure sounds like it was incorrectly charged. Ive seen this before. Just my .02

 

No, the charger was top of the line and I set it on 12V trickle charge which I read somewhere that is what these Optimas need. I am not color-blind and am sure that it charged red-to-red and black-to-black. Maybe it was charged incorrectly, but I have been around awhile and never had a problem charging a lead-acid battery. I think the gel dielectric that is used inside these batteries needs to be charged differently than a standard battery. This is just a guess, however and I am happy that things didn't turn out worse than they did. The Optima battery design is very similar to the alkaline battery, just on a much bigger scale. We all know what happens when you try to charge an alkaline battery, right?

 

Is what happens. Hmm im sure you matched the colors correctly im not sure beyond a trickle charge what the maintence free cycle does for you but it certainly seems that the dielectric gel was super heated. Is it possible the top post positive post side (I am assuming this is a top and side post model) ground against the underside of the battery holder? Optimas are super snug in vettes (Height challenged). The battery could have rapidly swelled sue to it discharging against the frame of the car.

 

As Mr Spock would say "Fascinating". I have charged mine several times and have never had a problem. Thanks for the heads-up.

 

Just a bit off topic. I got a catalog from Summit Racing called Genuine Hot Rod Hardware Inc. Look at this cool (and pricey) Optima battery holder:

There was a lot of great stuff in there. More at www.genuinehotrod.com

 

Your battery had sulphated plates and a small active plate area remaining. Effectively you had a motorcycle battery and the alternator is going to try to maintain 14.7 volts output and limit the current to 105 amps (or whatever the current rating is). 105 amps through a gel type motorcycle battery is going to cause lots of heat, outgassing, and gel boiling, expanding the battery case.
One mistake you made is not maintaining the battery during storage. Lead acid batteries (gel batteries are lead acid, the acid is just in a gel) don't like sitting doing nothing for long periods (4+ wks) and they self discharge even disconnected. During discharge, lead sulphate collects on the plates and if left, it gets hard and will no longer convert back to lead and sulphuric acid when charged. Hard lead sulphate is an insulator and a fully sulphated battery will not draw current when charged and is a door stop. ALWAYS keep your battery charged up during storage and it will experience a normal lifetime. Best way is to buy a battery tender which measures the battery voltage and only charges it when the battery loses about 10% of its charge, then turns off. You can use your battery charger and charge your battery once a week for an hour or so. You can also buy an interval timer (turns your home lights on each evening when you aren't home) and use it with your charger to charge your battery each day for its minimum interval (usually 15 mins), even one hour a day won't hurt your battery.
Even a motorcycle battery with 14.7 volts across it is the normal charging procedure, but probably your battery had a cell short shortly after you started the car and a 10 volt battery with 14.7 volts across it is going to draw a lot of current.

 

Which redtop did you have? The light grey or the dark grey?