Darosen1

I leave this Friday for a business trip and will be gone 23 days. Will I have any issues starting the car when I get back? ie the battery possibly dying? I’ve found info online and sources say it varies on make and model. Generally says no longer than 2 weeks but curious if anyone has experience with leaving it longer?

Galen Foster

maybe issues with battery rundown due to the internal electronics still drawing power.

toosteeley

Good chance your starter battery will be dead. Best to plug in a trickle charger.

Darosen1

Would I be able to just unplug the battery then instead?

Ramsino

Yes, I was gone for a month and unplugged my battery. Keep in mind that if you do this, you will have to redo all your settings: radio, clock, favorites, etc.
A few more things to note:
- Make sure that your physical car key actually works because you may not be able to get back inside your car if it's locked to open the hood.
- Cover the battery cables and terminal with a bag and tie it up or something so that it is air tight to reduce moisture from getting in.

toosteeley

^ good suggestions here.

stockbmw

Battery maintainer is the way to go.

mo11

I’ve left mine for a month when I was on vacation and it started right up when I came back. The battery was a little over a year old at that time. But it’s better if you connect it to a trickle/maintainer/charger.

EdC43AMG

You could use a CTEK or similar trickle charger. I am using a 5.0 in mine and works perfectly, with the covid restrictions we had here in Spain and now mainly working remotely from home I don't take the car too often and is a great option.

Also you should check the owner's manual. Like the Keyfob it has a Standby mode to reduce at maximum the battery consumption in case the car will be stopped for a long period of time.

It's called "stand by" mode.

In the owner's manual says that leaving the car over 4 week could cause discharge of the battery and severe if is over 6 weeks.

also with the mercedes me app you could track the status of the battery.

Regards

superswiss

FYI, the standby mode is only for the FL as far as I can tell, but yes it's a great feature. Not only does it turn off the telematics and Internet connection to avoid unnecessary battery drain, but it also displays how long the car can be left parked in standby mode w/o risking a dead battery and yes the Mercedes me connect app alerts if the battery reaches critical charge (not if standby mode is on, though, as there is no data connection). The PFL with mBrace doesn't do this.

I would also recommend to put it on a trickle charger. Disconnecting the battery has other consequences like losing your adaptations and other stored data. Just get the official CTEK charger. Don't get it from the dealer as you'll pay the OEM tax. You can get it cheaper at the link below, or get a tender at your local auto parts store and make sure it's compatible with AGM batteries.

https://www.juicemyride.com/products...31906962833469

SoCalC55

With working from home since last March and going 2-3 weeks between drives, I bought and have been using the CTEK Multi US 7002 on my car since last summer.
Love the eyelet terminals that come in the package, makes it real easy to connect and disconnect once hooked up.

I'm sure there are cheaper options but the technology and piece of mind the 7002 provides is well worth on a $70k car


Edit: Adding some wire placement pictures:

Darosen1

Wow thanks for all the responses guys. Looks like the ctek is gonna be the best option for me then

blaise

^^Definitely agree. loosing your setting will be annoying if you decide to just disconnect battery.