Thats not good .

[Slick Rick]

Had a bad smell in the laundry room thought it was drain related. It was a over charging batt. on a stored car in my basement garage. So this optima red top 4-5 years old batt. being maintained by a optima digital 1200 charger .So the charger was charging all it could cooling fan on and the charging cables hot and soft the batt. was 173 F I got the inferred heat gun out when i could not touch it ,you could here the batt. hissing venting I backed away. I had put this charger on a month and a half ago for trickle charge as a maintainer only. This should never have happened in this day that charger should have never been charging full tilt on a shorted batt. If my garage was not in my basement and I did not smell it overcharging what would have happened. In a detached garage fire I would think. Basement garage can be good and bad like everything. Oh yea I threw that charger in the trash only trickle chargers from now on for maintaining batt. nothing with high amps for storage.You know when you buy some of the most $ batteries and chargers Optima and it might burn your house down.

 

[JHZR2]

You have to be careful. Lead acid and AGM batteries do thermally run away and it’s not pretty...

 

[Lubener]

The battery is toast as well.

 

[SubLGT]

If the charger voltage spiked high enough, it could damage the ECU and other electronics in your vehicle. Hope you disconnected the negative cable before hooking up the charger.

 

[tyman]

Optima ftl

 

[tmorris1]

I haven't heard good things about Optima batteries. Lots of problems for the price. Hard to say in your case if the problem is the charger or the battery though.