MB cant figure out why my battery dies in 4 days.
 

i took the car to MB dealer (only one official here in HK)
and they checked for 4 days and couldnt find out anything wrong.

they just said the battery water ratio is not suitable but dont know if it's the cause.

also, my car had strange sound (bon bon bon, like farting) at the boot bottom when I stopped the car after I accelerated to 3500rpm (around 160km, or 60km uphill). it is due to the exhaust pipe. they reposition it and it's now OK.

Are you sure its just not a bad battery? The average life seems to be 3 years here in the states. (at least in this climate)




Joe

dead battery
 

My recently purchased 2000 S500 did the same thing, went through 3 delivered new MB batteries. Took it in and it turned out to be something in the A/C ( a switch or something).

tested with 2 batteries, one old 66A, one new 100A. both dead in 4 days. exactly 4 days.

Hi

I assume the dealer checked the alternator charging functionality.
I am not an expert but you should be able to measure across fusbox what is drawing current with vehicle parked up with a decent digital multi meter.

Failing that adopt a trial methodology (which obviously takes time)record and take out half the fuses and observe results. If battery OK then you know the circuits served by the fuses left in place are OK BUT one of the circuits served by the fuses you removed MAY be the culprit etc etc.

Good luck and keep us posted.