Just washed the TL today, and when doing my usual under-hood cleaning, I removed the plastic cover over the battery and noticed a white sublimate around the edge of the battery top. It seems to be right where the top is cemented? to the sides. I have seen the white stuff on terminals before when they have not been properly protected. The car has 7000 miles on it. Is this something I should go running to the dealer about or just keep an eye on it for a while?

 

You don't have to run to the dealer, but you should get it checked out. I have also seen this happen when the battery was overcharging due to a faulty voltage regulator or alternator, and there also could be a leak in the battery case.

 

I would disconnect the posts, clean them with a wire brush, put some wheel bearing grease over the post and the clamp and the problem will go away/ not come back.

I believe it is the acid from the battery that causes reaction with the posts. If you will put grease over the posts, it will not effect the electrical connection, but will prevent the acid reaction.

I hope it helps. My

 

Thanks, but there is no corrosion on the posts/terminals. Just on the edge of the case. I also noticed that on this Delphi battery there are 2 vents that are just open to the engine compartment. On my last car, the battery vents were connected to a tube that led to the wheel well, so that no hydrogen gasses were set loose in the engine compartment.