Is the DC-powered stuff in my truck corroding my battery terminals?

January 17, 2004 3:40 AM

I was going to ask these guys, but I'm sure we can come up with an answer here. I use some DC powered "stuff" in my truck and I'm afraid that it may be causing corrosion on the battery terminals. True, false, indeterminate based on the facts presented?
posted by ajpresto to (5 comments total)

I currently use a standard adapter for a portable CD player which I have rigged to play through a tape deck (how old school) to play Audible stuff on CD-RW, since my in-dash CD player can't read CD-RW. This is the cheap method until I can find some money to install an MP3 capable CD player in dash.

I also currently have a cell phone charger plugged in to the dash, which I keep plugged in at all times. I'm pretty sure that nothing bad is happening because of this, although it does have a cute little Cingular icon that lights up and is lit whenever the truck is running.

In the past, however (and this is when I noticed some relatively significant corrosion), I ran a power inverter, which I purchased for the express use of being able to plug in whatever I wanted to the truck. I wonder if running the inverter, which has a fan that runs all the time power is supplied to it, may have overdrawn something or whatever to cause some relatively minor corrosion.

Yeah, I know I said it's significant and minor. Well, it is. Both. It's more than I've seen before and it's maybe 1/4 of an inch thick on the terminals. There is a little that appears to be leaking out of a seam in the battery, but that may be overflow.

So, I guess the ultimate questions are, do I scrub off the corrosion (probably NOT using the Coca-Cola trick)? I've read that baking soda and water and a brush can do the trick. And you can smear some petroleum jelly on the contacts to help prevent corrosion. Should I do all that? Should I be worried that this has happened?
posted by ajpresto at 4:14 AM on January 17, 2004

There is a little that appears to be leaking out of a seam in the battery.

Considering this, my first thought would be to invest in a new battery.

It's likely that the corrosion is unrelated to the connected gizmos but is a result of leaking electrolytes (overfilled cells) or gases being vented (overcharging). Corrosion can also be caused by incompatible metals, make sure there are no washers connected to the terminals and that your using quality cables.

Batteries are intended to be closed systems and yours obviously isn't. No need to panic, but these things have been known to explode and nothing wipes out a pair of jeans like wiping battery acid all over them. Batteries aren't all that expensive and I would get one that doesn't leak and while your at it test the alternator output to make sure it isn't overcharging the battery.

As far as cleaning it goes, just use a wire brush to scrape it off, they make special ones but anything should do. The grease may increase conduction and slow the spread of new corrosion, but there is something wrong here and masking the symptoms is eventually going to leave you on the side of the road with an uncharged cell phone.
posted by cedar at 6:02 AM on January 17, 2004

I think cedar is exactly right.

If you replace your battery, I recommend an Optima if you have a few extra bucks to spare. If you don't, you should still spring for an Interstate.

The technorati on most of the foreign car mail lists say to avoid DieHard, Exide and Duralast batteries at all costs.
posted by trharlan at 7:14 AM on January 17, 2004

"I've read that baking soda and water and a brush can do the trick."

Baking soda and water is an excellent battery cleaner.

"...you can smear some petroleum jelly on the contacts to help prevent corrosion"

Better yet, buy a pair of felt washers (to put under the terminals) and a can of spray-on battery terminal protectant (to spray over them when you're reconnected them) at Checker, Autozone, or whatever chain store happens to be nearby. All together they should cost you under four dollars.
posted by mr_crash_davis at 10:57 AM on January 17, 2004

we used to use coca-cola to clean battery terminals.
posted by quonsar at 1:02 AM on January 18, 2004