Lithium-Ion battery?

[Qsilver7]

Originally Posted by TiAgX5

Lead acid batteries explode too.

There were 2 Xout members in Europe that posted carnage threads here with pics of bomb batteries and acid in the rear electronic wells.

There are several bomb battery posts on E46fanatics too.

Yes they do...but the question I ALWAYS want to ask or consider when I hear/read of this on a BMW forum is...was the battery vented properly.

A lead-acid battery produces hydrogen gases as a by-product of the process it creates power/energy etc...and those are the gases that need to be vented to the exterior of the vehicle.

The gas doesn't explode without a spark...and what a lot of unknowledgeable owners don't realize is...a spark can be created when driving around town by a surge or quick overcharge by the alternator/charging system. The spark doesn't have to come from an outside source while working around the battery compartment. Thus the vent tube is designed to carry these gases a way when the battery produces them...which in turn can prevent the battery from exploding if a spark is introduced during an event where the gases could have accumulated in the non vented battery compartment.

The image below is an old image (from around 2003) that was from an e38 owner that hadn't vented his BMW lead-acid battery...which exploded when he had started the vehicle and was leaving a parking lot...it was my first "aha" moment of the real importance of battery venting:

BTW...another misconception that floats around the car forums is that AGM batteries don't require venting...but that's incorrect...they ALSO require proper venting to the exterior of the car.