R350 - Battery suddenly drains

[Kingpin!]

Hi, forum!

A couple of days ago my battery was almost drained. I could open the doors, fans was working, COMAND and electric hatch/back door etc. but as soon as I tried starting, the starter motor just hadn't enough power ("tick tick tick"). I charged the battery almost 24 hours (my CTEK was at the last level), disconnected the charger and the car sat for the day and night. Now (today) I was taking the car for a spin and it was even more drained than before (electronic hatch/back door would not open but doors could be unlocked so I could open the hood and connect the charger to the charging points (battery is under the front passenger seat in R-Class).

Anybody has any idea on what could be (suddenly) draining my battery/what to check/look for?


TIA!

 

[Giantvanman]

Are you sure something is draining the battery and not the battery failing to hold charge? I would test the battery first…is there one or two batteries in the R?

 

[Kingpin!]

Are you sure something is draining the battery and not the battery failing to hold charge? I would test the battery first…is there one or two batteries in the R?

There is one main battery and one little which is used to engage the gears.

Is it really possible that the battery is acting up from one day to the other, I mean this drastically?

 

[Kingpin!]

Hi, forum!

A couple of days ago my battery was almost drained. I could open the doors, fans was working, COMAND and electric hatch/back door etc. but as soon as I tried starting, the starter motor just hadn't enough power ("tick tick tick"). I charged the battery almost 24 hours (my CTEK was at the last level), disconnected the charger and the car sat for the day and night. Now (today) I was taking the car for a spin and it was even more drained than before (electronic hatch/back door would not open but doors could be unlocked so I could open the hood and connect the charger to the charging points (battery is under the front passenger seat in R-Class).

Anybody has any idea on what could be (suddenly) draining my battery/what to check/look for?

TIA!

I charged the battery until this morning and the CTEK had reached the last level (green LED lit) which I think means that at least the charger thinks the battery is good and holds it's charge. The car is parked now and I will check the status later this afternoon (after the GP).