Battery advice needed

[Maxngm]

Just had the main battery and altenator replaced on my w211 e320 cdi and the warning signal has come back on to say conveinnce features are disabled to protect the battery (the same as before I had it replaced).

What could be causing this and am I still OK to drive it as I'm concerned the battery is going to run out leaving me stranded (can't get it to my garage until monday).

 

[optimusprime]

Did you cancel the battery failure ..clear the codes after new battery ?

 

[Maxngm]

Did you cancel the battery failure ..clear the codes after new battery ?

I'm assuming my mechanic would have done as I have driven it around 50 miles since the work was done and its only just come back on.

 

[Bobby Dazzler]

My first thought was to clear codes too.

 

[markjay]

You may have parasitic draw, where a failed component draws too much current and depletes the battery.

The old school way of diagnosing this issue, was to disconnect the battery (with the ignition switch in the off position and key removed), connect an ammeter in a serial connection, then watch the current draw. If you can, shut the bonnet and lock the car while the ammeter is outside the engine bay (the only issue is that ammeters don't like long cables).

But there may be more modern ways if diagnosing parasitic draw these days.

 

[Mcfurter]

Hi there
I have a 2018 C350e and have a battery warning light and a "dont change gear consult workshop" warning coming up intermittently whilst
driving.
Sometimes the car wont start and the warning "this car cannot be towed" comes up but normally clears after half an hour or so and the car
will start then.
The main 12v battery in the boot has been changed but still seeing fault. Can anyone advise on the part number
for the correct auxiliary battery for my car, the battery is the one in the foot well?
thanks