Battery cell caps -- how. . . - PeachParts Mercedes-Benz Forum

Benzadmiral · #1 12-15-2004, 09:31 AM

. . . to remove, that is?

Car is a 1997 C230 w/ the white battery in the (frickin' &^&%*&) trunk. I've looked, and as mentioned in a post about a month ago, it has six cell caps w/ big Phillips-screwdriver crosses on them.

1) What size screwdriver do I need to remove these? I'd like to go to Ace or PepBoys and tell them what size, instead of calling somebody out, peeling back all the stuff in the trunk, and showing him the battery.

2) Another post has me wondering. Can I top up the cells with the battery in the car, or does it *have* to come out?

3) Distilled water, or tap water?

TIA,

scjim · #2 12-15-2004, 11:40 AM

1. I use a regular screw driver with a wide tip.
2. I fill in the car with care. Griots Garage show a water bottle with a tube that looks handy. I use a rubber squeeze bulb for filling batteries.
3. Use distilled water.

schumi · #3 12-15-2004, 11:48 AM

if it is the kind of battery I'm thinking of, the caps are designed so you can use a coin to open them (a quarter works well). as for the rear location, that is something I think only German car companies (some Mercedes and BMW models, and rear-engine Porsches with battery in the front is same idea) do to even out the weight distribution in front engine cars, which improves the handling. I wish my cars had rear battery!

G-Benz · #4 12-15-2004, 01:23 PM

Quote:

Originally Posted by schumi

...as for the rear location, that is something I think only German car companies (some Mercedes and BMW models, and rear-engine Porsches with battery in the front is same idea) do to even out the weight distribution in front engine cars, which improves the handling. I wish my cars had rear battery!

I think it's actually because of limited space for a battery in certain engine compartments...My VeeDub has no engine compartment space to accomodate a battery but the Karmann Ghias do. Rear-engined Porsches has the same logistics problems as far as batteries are concerned.

My R129 has a rear battery as well...there is NO WAY they could get a battery up front, and that's just for the V-8...imagine the V-12!!!

manny · #5 12-15-2004, 01:36 PM

My battery weighs 52 lbs.

and I prefer the trunk location, to help balance out the weight.
Also, just another theory of mine, the heat in the engine compartment probably has some negative effect on battery life ?

Gary Ganaway · #6 12-15-2004, 01:49 PM

I use a regular wider blade screwdriver to remove caps. I then use a turkey baster and distilled water to top up, which I check every month. I put in a new MB battery earlier this year and the old one was the original...pretty long life compared to Autozone batteries I used to puat in my Jeep Gr. Cherokke. Only good thing about the Autozone was the 3 yr replacement warranty which I used 3 times in 6 years!

schumi · #7 12-15-2004, 02:19 PM

BMW at least does it for weight distribution (e.g., some models have an unused battery tray at the front and battery in the rear). But they're much more performance oriented co. than MB.

Quote:

Originally Posted by G-Benz

I think it's actually because of limited space for a battery in certain engine compartments...My VeeDub has no engine compartment space to accomodate a battery but the Karmann Ghias do. Rear-engined Porsches has the same logistics problems as far as batteries are concerned.

My R129 has a rear battery as well...there is NO WAY they could get a battery up front, and that's just for the V-8...imagine the V-12!!!

Benzadmiral · #8 12-15-2004, 02:31 PM

. . . with putting the battery in the trunk, for me, is that I have to (a) find a way to prop up the trunk floor mat while I work on the battery, and (b) spend a long time in an awkward, bent-over position.

But I agree that putting it back there isolates it from engine compartment heat, and probably helps with the weight distribution, as you all pointed out. It's just that it's easy to forget it when it's out of sight back there.

Looks like I should just use a quarter to open the cell cap -- maybe clamp it in a pair of locking pliers -- turn each one until it's loose, and remove it with my rubber-gloved fingers. I have a little squeeze bottle with a narrow spout I can use to administer the distilled water.

Thanks to all for helping with what must have seemed a silly question,

manny · #9 12-15-2004, 04:20 PM

Why do you have to prop the trunk mat?
It takes 2 seconds to pull it right out.
And, while you're in there, check the tire pressure on your spare tire.

BMW more performance oriented........he, he, I'm going to pee my pants.

mpolli · #10 12-15-2004, 07:55 PM

Quote:

Originally Posted by Benzadmiral

. . . I have to (a) find a way to prop up the trunk floor mat while I work on the battery, and (b) spend a long time in an awkward, bent-over position.

The black plastic handle on the mat snaps open to become a hook that hangs on the trunk front edge. See, they thought of everything.

Mike

Carlos Serrano · #11 12-17-2004, 09:54 AM

Get rid of it
Replace it with an AC Delco 6 year warranty Battery sealed battery It will last almost as long as the warranty providing your charging system is working

Benzadmiral · #12 12-20-2004, 08:36 AM

While waiting for the oil to drain into the Topsider, I went back and checked for the battery. I had to take everything out of the trunk, but then the mat clipped easily onto the top edge of the rubber seal for the trunk, out of the way. The quarter worked fine to open the cells.

But it took me nearly a half gallon of distilled water to fill the cells!

When I say "fill," I mean just up to the point where I could actually see water not far below the lip. When I first learned about cars, the rule I heard was to fill the cell to the lower edge of that little vertical slot, and I aimed for that. But the battery must have been almost bone dry!

The car starts immediately (and, amazingly, was doing that before I rehydrated the battery). Could the battery be on its way to dusty death? Should I have it checked?

tower · #13 12-20-2004, 10:42 AM

Don't be surprised if the battery goes south real soon. Had a similar situation and found that where the acid wasn't becomes sulphate (sulphide?) up very quickly and with acid now in contact, could short the plates.

Gary Ganaway · #14 12-20-2004, 11:08 AM

I have to add water about every 3-4 weeks..not a lot but it always takes some. When I first checked my original battery after owning the car a few months it too took a lot of water, as it aprobably was not checked very often. After about a year and 1/2 the cranking become slower and slower and finally had new battery put in. Original lasted 7 years.

mpolli · #15 12-20-2004, 12:27 PM

Quote:

Originally Posted by Benzadmiral

While waiting for the oil to drain into the Topsider, I went back and checked for the battery. I had to take everything out of the trunk, but then the mat clipped easily onto the top edge of the rubber seal for the trunk, out of the way. The quarter worked fine to open the cells.

But it took me nearly a half gallon of distilled water to fill the cells!

When I say "fill," I mean just up to the point where I could actually see water not far below the lip. When I first learned about cars, the rule I heard was to fill the cell to the lower edge of that little vertical slot, and I aimed for that. But the battery must have been almost bone dry!

The car starts immediately (and, amazingly, was doing that before I rehydrated the battery). Could the battery be on its way to dusty death? Should I have it checked?

As far as fill level, I did as you did but later noticed that on the side of the battery there is a fill line which was lower than what I was filling to.

As far as life, there was a recall on the batteries on the 98's. Not sure about the 97. You could get in on that if it was never done. Part of the reason for the recall was that the manual did not mention to ever check the level in the battery.

Mike