I drive a 2000 E430 and the battery exploded today! Has this happened to anyone else? What causes this? Car is still under Star Mark warranty and was serviced less than 2,000 miles ago. Thanks

 

My 99 C280 is on its third battery, the first one changed under recall, the second one kinda exploded in that is leaked acid all over the trunk. At the time the car was under starmark, but the battery was just over 2 years old and I had to pay for it. I understand these early batteries were made by a different supplier and somtime after 02 they changed suppliers, and so far the 3rd battery seems to be OK and is going on 1 1/2 years but I still need to add water every month to 6 weeks. Distilled that is.

 

Can you describe how it exploded? Was it a "BOOM" and pieces of plastic and battery were scattered all over the compartment or was it where the case cracked and the acid leaked out?

Batteries generate hydrogen gas, even the sealed ones. If during charging (vehicle running), or worse over-charging, there is hydrogen gas liberated. It there was a spark or arc anywhere near it ther battery could detonate.

Two other types or battery failure are;

The battery is chronically overcharged, it will overheat, swell and split, also making a big mess. I have seen batteries that ended up shaped like cantelopes because the plastic melted, the case swelled and it cooled into the new shape.

The battery suffers some type of internal failure. eg, plates short out causing a massive current surge that will blow the battery "down", through the bottom or sides of the battery.

If the top is missing I would suspect a hydrogen initiated explosion, if through the bottom or sides I would suspect an overcurrent event.

 

I do Mercedes Roadsides at my dealership. Iv replaced many blown batteries. Its mostly common on HOT days and also when the bettery is low on fluid. When they explode you will know it for sure and the outside shell of the bettery will break into pieces and acid will leak out. Be carefull and wear eye wear and gloves. or just call roadside!!