Battery Tray Corrosion
 

I have a 99 ML 320 and have experienced significant corrosion on the battery tray. I took battery out, cleaned, sanded and repainted everything about a year ago and now the corrosion is back. Does anyone know the cause and a permanent solution?

Are the terminals and clamps all corroded too?

Honestly can't tell you. Just got the truck serviced and they installed a new battery. I took a look under the hood to see all the work was done and noticed the corrosion again. It's my wife's daily driver and I don't get under the hood as much as I should.

Let's assume they were. Would that spread to the rest of the battery tray?

I've owned three or four cars which have suffered significant battery tray damage, my 190e no longer has a tray to speak of. By the time I bought it, the tray had turned to rusty bits which I actually vacumed out. I painted the remains and the whole area the battery sits in with Hammerite and will try and find a replacement.

Why is'nt the battery area treated with zinc or a strong plastic lining?

Mike.

Don't know why your battery is causing corrosion, but to prevent in the future, clean all the old paint off (as much as you can). And then apply POR-15. See here. This stuff works.

Another method you can try is:
- brush the tray with a bicarbonate of soda solution to neutralize any remaining acid salts
- remove any rust with sandpaper or a wire brush
- prime with Rustoleum "cold galvinizing"
- top coat with Rustoleum of your choice of color.

battery tray
 

You might check to see if it is over charging, boiling the water out of the battery..:D

That is really fast deterioration. Battery may be leaking.

I once fit a metal tray with 'Ice & Water' roofing membrane. Actually worked quite well! Very cheap, since I had a big roll anyways. A roll of the 6inch wide stuff for sealing around windows is only about $12 at the home center.

Performance Products and some other places sell special battery tray liners that neutralize acids.
I have seen cars refit with marine-type battery boxes as well, but could be a tough fit for many cars.
Some folks swear by spiral-cell batteries like Optima. These can be mounted upside down without leaking.

http://www.drivewerks.com/catalog/im...w_batt_mat.jpg

This place has mats too:
http://www.drivewerks.com/catalog/shopcart/CARE/POR_CARE_MISCcc_pg7.htm

Your battery should have venting hoses attached to the hole in the center. MB did not do this as standard on the 98 ml, which I have, & probably not on the 99 you have. You can check with the dealer or any store that sells replacement batteries.

Also, Eastwood sells a battery tray coating that I have used with good results. Need to remove and/or convert all rust before application. I primed and painted mine too before the coating because overkill is what I do...

http://www.eastwoodco.com/itemdy00.asp?T1=25011+Z&Dep_Key1=



http://cache.eastwoodco.com/images/P588.jpg

I concur with CSNOW's advice. The battery mat worked very well in my Porsche.

Thanks to all. Many great suggestions. I will clean, neutralize, sand, prime, and paint this weekend and will also order a battery mat.

Feedback on Optima remains positive. There have been enough in the field long enough for good 'burn in' at this point.
You can mount them in any position, even upside down if you like. The 'collector car' and marine folks I know rave about them, since they survive long term storage well. I have not yet tried one first hand, but my next marine battery will be an Optima.