I've removed the AGM Deep Cell 6V RV batteries for the winter and will trickle charge them every month. However, the Mercedes battery under the driver side floor is another matter. Thinking of connecting a NOCO 2Amp 6V smart battery monitor with trickle charger to the battery boost contact posts under the hood rather than remove the battery. Haven't checked with Mercedes for recommended charge unit. Any advice is appreciated
What temperatures?
I have mine sitting all winter for 5 months in as low as -15C I pulled the battery isolating cable by the drivers side near gas peddle. It is 6+ yrs old in a 2015 chassis. and still working with no trickle charging. If you have a newer model there is Fuse 32 that also need to be removes as that controls that auxiliary battery under the passenger seat.
in the manual you nee to search for battery isolating to find it.
FYI I was expecting to have to get a new one this year but it worked just fine all summer/fall.