Wxchaser

Any help or advice greatly appreciated!! Currently on trickle charger overnight, hoping I can make it 60 miles to the dealership.

Due into MB for Service B appointment this afternoon. Getting numerous messages and emails about battery charge status critical (The state of charge of your vehicles starter battery is critical).

This has been going on for a few months now but not at critical level. I have had to resort using my trickle charger many times. Purchased Nov. 2020 current mileage is 4,121.

My main suspicions:

1) Bad battery
2) Faulty Capacitor/Startup Battery - (in passenger footwell?)
3) Possible bad starter relay

Hopeful that MB service techs can pull a code & fix!

Wxchaser

Trickle charged overnight
I haven't yet started the GLC 300 after trickle charging. I feel like the battery drains rapidly. Another suspect is wireless CarPlay adapter being left plugged in all the time?

My Mercedes me iPhone app seems like it doesn't update status in a timely manner?

Pretty sure I will have no problems getting to service appointment now.

sn202020

Check battery voltage duribg engine off and on at system menu.

off. Beteeen 12 ~12.5 good battery
start engine.
On. 14 ~ 15. Good alternator.

Bad alternator is under 13 volt during engine on.
you can't drive usually more than 30 minutes with bad alternator.