W204 battery or alternator ? Or something else ?

[NewbietoMB]

Hey guys just having this issue in my 2010 w204 c250cdi 651 engine . Replaced battery for new 3 months ago . When starting the car from cold start it struggles abit then starts . That shouldn’t be happening . I checked onboard information regarding the battery etc on the engineering menu of the car see attached .

I’ve uploaded a video on YouTube of the startup ….

 

[AMGeed]

The supply voltage is too low but it appears your alternator is fine and charging the battery as it should when running.

Is the car used infrequently? You may have a drain on the battery causing it to be under voltage.

I would put the battery on charge until its fully charged and see how long it takes to drain down. 12.6v+ is fully charged.
You may need an auto electrician to pull fuses to find what component is draining the battery.

 

[NewbietoMB]

The supply voltage is too low but it appears your alternator is fine and charging the battery as it should when running.

Is the car used infrequently? You may have a drain on the battery causing it to be under voltage.

I would put the battery on charge until its fully charged and see how long it takes to drain down. 12.6v+ is fully charged.
You may need an auto electrician to pull fuses to find what component is draining the battery.
View attachment 79111

Thanks for your reply really appreciate it. Car is driven everyday it’s my daily.

 

[alexanderfoti]

Starter motor if battery is good. We do quite a few and they do this just before they fail.

 

[NewbietoMB]

Starter motor if battery is good. We do quite a few and they do this just before they fail.

Thanks for your reply Any other input welcome form anyone else

 

[NewbietoMB]

Hey guys just an update . Past 2/3 days cars been fine again . Not struggling to start as before . Any ideas what this could be ? I’m trying to get to the bottom of this wether the alternator needs changing or the starter motor or the fuses need checking ?

Any help would be good thanks