New Battery Maintenance Free?

[DaveJ]

A few weeks ago my Mercedes dealer replaced the battery on my '98 W210. The man that installed it onsite said the new battery was sealed and did not require maintenance, unlike the original battery. I never knew I was supposed to add water to my original battery, which lasted over 75K miles.

I called the dealer parts department regarding the battery and someone told me I should check the cell levels at every maintenance interval and add distalled water as necessary.

So now I'm confused. Can water be added to these batteries and should this be done? If so, is distalled water still the appropriate choice or is there something else that should be used?

Thanks.
Dave

[tangofox007]

Look at your new battery to see if it has caps on the top that can be removed. If it does, then you should add distilled water (and nothing else) to maintain the electrolyte at the proper level. Check it monthly, especially in hot weather. Allowing the electrolyte level to drop to the point where the plates are exposed to air greatly reduces the life of a battery. If there are no removable caps on the battery, then I would conclude that it is a "maintenance free" model, which has no provision for adding distilled water.

what color is the battery? if it is black it is mercedes new type battery that is sealed. it has gel type acid, much like the optima battery.
Ray
mercedessd@cox.net

[DaveJ]

I haven't had a chance to pull the rear seat to check the color of the battery, but I believe it's the same color as the one replaced recently on my '01 SLK320.

The color of that battery is kind of clear/frosted white. It has 6 large flush phillips-head type round caps that I assume are for the individual cells. The size of the caps are about the size of a quarter.

I haven't tried to loosen any of the caps.

Does this help determine if water should be added to the battery?

Thanks.

[R129]

Yes, you can remove the caps (there should be 6) and add distilled water if it goes below a certain level. This level marker should be along the sides of the battery.