Plan on needing a jump start and maybe a trip to the MB dealer to reprogram.

There is no way I can use a battery tender and some models have a sleep mode mines does not guess \i have to hope theres something left in the battery need to be careful with jumpstart Thanks to all

Check your owner's manual or visit your local Mercedes Benz Dealer. Simply disconnecting the negative battery cable when you park may be all that you need to do. I do that with my own vehicles that I don't drive much. But they're older models. Hope that helps! Jim

The W213 Online Manual says If you do not intend to use the vehicle over an extended period of time: Activate standby mode, or Connect the battery to a battery charger approved by Mercedes-Benz, or Consult a qualified specialist workshop to disconnect the battery. To Activate or deactivate standby mode: Multimedia system: Vehicle / Vehicle settings / Standby mode Activate or deactivate the function. When you activate the function, a prompt appears: Select Yes. Standby mode is activated.