Help required for MERC C250 coupe blueeffi petrol 2012

[CoiaJR]

Hello so I purchased a C250 coupe the other day and was told the only fault was the back boot battery was faulty as the terminal had snapped so we replaced this and still got low battery replaced big battery all was fine how ever the start stop function still was not working eco would light up where the stereo is but when car started and running would turn off and would not be able to be turned back on

 

[sonic]

You need to get the codes read, & check the voltage of both batteries engine on & off.
You will then have a better idea of the fault.

 

[CoiaJR]

You need to get the codes read, & check the voltage of both batteries engine on & off.
You will then have a better idea of the fault.

Hello I am taking it to a garage tomorrow for codes to be read regarding the battery I have change both of them today brand new from Mercedes

 

[Gazwould]

Waste of money that 5kg auxiliary battery .

 

[CoiaJR]

Waste of money that 5kg auxiliary battery .

The earth was snapped so had to be replaced car was showing no codes but since has got another dead battery after both being replaced yesterday

 

[Misterdog]

You need a digital multimeter, set to 20 volts DC read battery voltage when cold (engine off) then start engine and read after 2 minutes.

Or keep swapping batteries until your bank account is dry.. and be none the wiser but broke.