MelvinC

I have a 2012 E350 Mercedes just about 50,000 miles . Just recently I changed my main battery under the hood on the passenger side about 3 months ago due to the red light battery turning on. I changed the battery which stopped the light from popping up again. After a few months driving, All of a sudden the light popped up again but this time it's starting to command to shut off my radio and other unnecessary features in the car. Any advice or suggestions on how to fix this situation? I'm really hoping it's not a alternator problem.

The G Man

Its neither an alternator problem or a Parasitic current drain. Howmany mile do you drive a day and how many times a week do you drive your car,if your car is a garage queen, try using a battery charger.

MelvinC

Let's say it's my commuter .. I drive it everyday . About 30 miles a day I would say..

MelvinC

let's say it's my commuter . I drive it everyday . About 30 miles a day I would say .

belarus27

Main battery is bad maybe?

MelvinC

the main battery is brand new. About 3 month old I would say ..

Magicman09

It really sounds like the battery went bad. Even though its practically brand new, extreme low temperatures can really hurt a battery.

The G Man

30 miles should be enough to charge the battery, either you have a bad alternator problem or a battery drain when your car is off, I would start by getting a mechanic to test the alternator.

The G Man

30 miles should be enough to charge the battery, either you have a bad alternator problem or a battery drain when your car is off, I would start by getting a mechanic to test the alternator and the battery.

claus6421

hi.
Had the same problem. Red battery in display.
I read out the charging of the batt in the display (hidden menu)(Phone+ok)
It was charging when i checked but probably only periodic and i think that was why i got the red batt.
now i know it was the regulator/rectifier on the alternator.
But since the batt was charged when i checked i thought it was a bad aux battery and drove the car and the regulator went so bad it destroyed the copper in the alternator so now i need a new.

MelvinC

would the issue be the alternator? Maybe the regulator/rectifier ? And when you stated a new? Meaning new alternator?

claus6421

If i had changed the regulator/rectifier (coal) as soon as i got the "red battery" the copper track inside the alternator would not be as damage, as it is now.
One of the alternators copper track is in so bad condition now, so i need to change the whole alternator instead of just the regulator/rectifier.
The red batt indicated that there is a problem with charging the batt so i would inspect the alternator and maybe change the regulator.

BBB78

It's the alternator

LILBENZ230

You should try dyno mode to see exactly what the alternator is charging at. That's how I discovered a bad alternator in my W211.

MelvinC

dyno mood meaning ?

RetiredSD

Doesn't your model have a secondary trunk mounted battery for the electronics? if so, could it be that battery is bad and not the main as you thought. Did you get a load test done on the main battery before replacing it? Most auto parts stores do it for free. Good luck.