mbe2

Hello everyone, I have a E250, 2013 model with M271 evo engine, and I have run into some problems with the battery, which I hope I will be able to get some information about. I am currently away from home so I do not have access to too many fancy tools to diagnose for the issue.
So it has been a while that I have started the car, once I tried to start it it cranked and tried to start, but failed. So I took the battery booster from the trunk and tried boosting it for around 5 minutes (The standalone power booster devices basically.) But now, when I turn the key the car wont even crank. What it does is just one thump noise like some mechanism trying to start, but it only lasts about a second then nothing. The booster had a full battery, all dash lights work okay, infotainment system is up, but the engine wont even crank. Has anyone encountered such an issue? Does this mean that the battery needs replacing?
I'd love for any input or suggestions you all might have.

Thank you all.

Bruce Hubbard

More than likely the main battery in the engine bay is past its use by date
I leave one of these in the cig socket so that I can check the battery voltage in accessory position (ebay)
The cars won't crank if the battery voltage drops below a certain voltage (can't remember exact voltage, 11.5 volts maybe)
2013 car, so if the battery has never been replaced, it will need to be. You can check the date on it.
I use Century batteries (Australia) which is good quality but cheaper than the MB Varta
My E250 is 2014, so if yours is original battery it is 10 years old which is a pretty good run