I will be leaving my 2015 S550 W222 undriven for 2-3 months. I can't have a trickle charger because it will be in a parking garage that has no nearby power source.

Has anyone put a disconnect switch on their W222? I presume I would need to put it on the battery in the trunk.

Advice appreciated!

 

Not sure how good that would be for the Air springs as they will probably run out of air and bottom out, maybe someone more in the know could chime in on this? You may have to put the car up on jack stands if you do this idea. They do have those green knobs that mount on the positive battery terminal like used on a lot of hot rods I see at car shows.

 

The suspension would not level when parked and the car had time to enter deep sleep. The battery would not survive 3 months, calculate 80 mA times 3 months. I would disconnect the battery ground. Not a bad idea to have jack stands just to release weight from the tyres.

 

If you disconnect the battery you better make sure the trunk lid DOES NOT close and lock. these cars are all electrically operated in there locking systems so if you close the trunk your electric latch button will not work to open to reconnect battery. This is well known with BMW trunk batteries.

 

My W222 trunk can be opened with the mechanical key. Better to try that too.

 

I do not know what the daily draw is when the car is unused so I can't do the calculations, but it is conceivable that buying a second high-capacity battery and hooking it up via jumper cables might make the total capacity enough to survive the 2-3 months. Of course it would cost a coupe hundred for a second battery. But the advantage is that the second battery could be kept in your trunk with the trunk closed (which I presume is important as it sounds like you are in a shared parking garage).

I am sure someone else in the forum can tell us what the draw is and from that we could figure out how many additional AH you would need to survive the three months.

Just a thought.

 

Current draw typically some 80 mA on a car with an alarm. Would need 200 Ah total battery capacity at least for 3 months.

It would be safe to close the trunk if either the ground cable was disconnected or the plus was protected from not touching ground. Then one can feed power from the engine bay jump start points just to open the trunk (if one feels it easier than using the metal blade).