Redvelvetboots

Welp I got an email notification from my 2020 GLC that the starter battery charge status of the vehicle is very low. Knowing that I was going to be out of town all week I drove it two days ago (two 20 minute highway trips). I won't be returning home for another 5 days. How dead will it be? Will I need to jump start it? Thanks!

Teckno

Yes you may need to jump start, use something like NOCO GB40 , great accessory to have in trunk. Also something like CTEK battery charger, set to AGM and let it trickle charge whist you go away. I usually put one on our cars overnight once a month, when I remember. Helps battery life and should help alternator and electronics too.

superswiss

A week should normally not be an issue unless there's an unusual battery drain, or the battery was already pretty empty when you left despite driving it two days before, or you need a new battery. The thing is, these modern cars don't fully go to sleep. They maintain an online connection, so that you can remote start them etc. and send you battery alerts as in this case. To avoid this if the car is not driven for an extended period, you can activate standby mode if available. It turns off the online connection, but also the car alarm and any other consumers. It also tells you how long you can leave the car in standby mode before the battery needs to be charged.

I use this when I go away for 2 or more weeks. As you can see from the pic below, with a fully charged battery my C63 is good for 21 weeks. I mostly drive on weekends only and sometimes the car sits for up to two weeks in the garage, so the available standby time drops quite a bit with my normal use. Therefore, I usually hook it up to the battery tender the day before I leave and then put it in standby mode. Ahead of my most recent trip it actually gave me a warning that standby mode wasn't available, because the battery charge was too low, but after I charged it, it entered standby mode as usual and was fine for the 3 weeks I was away.