Yesterday I noticed a white powdery residue around the right side a/c vent area on the dash and the inside of the car smelled acidic. It felt like the build-up I have seen before on batterty terminals in other cars. I took a look at the battery in the trunk and sure enough,this stuff was all over the battery compartment and even on other parts of the trunk, but there wasn't any build-up on the terminals, which were very clean and tidy. I couldn't tell exactly where its originating from. Did some research on the forums and heard about the vent tube that's supposed to be there, but I don't think it is. The side of the battery compartment facing the back of the car has a hole that looks like a vent of some sorts, but there's nothing connected to it. Should there be something connected here and if so, how can I set about getting the parts I need. If it's not, any ideas on where this residue is originating from?

The car is a 2005 530i that I bought used about 5 months ago, and there are no other signs of the battery going bad. Everything works like its supposed to.

Thanks

 

Yes, there is a vent tube which should be coming from the battery to an outlet which drains outside the car...

 

The vent tube is connected to the positive terminal end of the battery.

 

That white powdery substance is corrosive. I recommend you remove the battery, vacuum up as much of the white power as you can, then wash the area thoroughly with a baking soda & water solution to neutralize the powder. It's possible that battery acid may have splashed around the battery compartment starting a chemical reaction with other items in the battery compartment. If you see any bare metal in there clean it up and apply some touch up paint to prevent further corrosion.

 

yikes, going to do this asap. Also, just having this substance present, is this normal and I just don't have the vent to funnel it outside, or am I looking at the battery replacement in my near future?