BB_45B

Went to check the battery fuild level on my 2002 C230K and the inside of the battery is not what I remember.

With all my previous car batteries, you filled until the fuild level touched the bottom of the opening. (you know what I'm mean.)

The inside of this battery looked different. Either that or the battery level was very low.

Any hints?:

mctwin2kman

Batteries are sealed now and have been in the automotive industry for over a decade. There is no filling or topping off of fluid anymore. Sealed and when the seal is broken bad things happen, like leaking, and leaking leads to corrosion of components you do not want corroded.

BB_45B

So those 6 opening on the top of the battery are not for checking fuild levels?

My M-Class, and RV's batteries (2-4 years old) look like I would expect. The RV battery is always being discharged and recharged (and in need of water)

mleskovar

If you saw the top of the plates above the fluid level then it needed water. The batteries that are truly "sealed" have the new spiral wound plates and do not have access holes to add water. Yes, fill to bottom of opening. I wish the spiral wound core battery makers (Exide, Optima) made a 100 amp battery for the new C class.

mctwin2kman

Every car I have ever had, had sealed batteries. Is this a lower state thing with warmer climates. My boats had ones you could add water to, but never in a car!! At least not in the 14 years I have been driving and working on cars.

vraa

Must be a southren state thing, in drivers ed one of the things you learn is checking the battery level and how to fill it with distilled water.

lars

If you need to add water to a modern battery there may be something wrong with your electrical system. That said, I have recently bought batteries that allow water to be added even if they appear at first glance to be sealed. Use distilled or deionised water or at the least very soft water. Adding hard water (water with iron, calcium etc) will reduce the power of the battery. Also, the more water you add, the more dilute the battery acid becomes and the less power the battery can sustain. The battery fluid really only needs to cover the top of the plates, which are usually well below the top of the inside cavity. I would stop filling with the level at least an eighth of an inch below the bottom of the filling neck, to allow hydrogen gas generated during normal charging to escape without causing an overflow of acid.

mleskovar

Lots of batteries claim "maintenance free" but that is bs. If they have caps and vents then be prepaired to replace fluid...especially if you live in a hot environment or spend a lot of time "off road" (shaking/spilling the fluid out). The new battery technology does not use a liquid bath but instead uses saturated plates that are tightly wound in a circle with no need for the bath....which means they can
be installed upside down if necessary. Any battery experts out there? Am I wrong?

BruNo

i thought d battery was maintenance free, so i didnt bother to check, but it went dead in less than 2 years coz wen we checked on it, d solution was below d optimum level causing one battery cell to die prematurely......and my mb dealer told me to check on it from time to time. if im not mistaken its brand is hoppecke..or sumthin like datttt... water should b level with the plastic band covering the holes, just above the plates.

CHATMANR

Bruno,
My battery died on me and Mercedes come to my house and replaced it for free; saying that there were issuses with the batteries on the C Class.

W0n6_3d4n

Yup same here, then i receive a recall later that month that something wrong with the battery or sth, changing the baterry will solve it.

BruNo

well in my country, RECALLS are unheard of...... welcome to the third world!!!!! u ppl are so blessed!

that stupid MB battery cost me $140.00 whereas my lexus battery only costs $46.00