My 2008 ML320 CDI has been in storage for six months with the main battery disconnected. I did not disconnect the small battery. The storage unit has no power so I was unable to keep a trickle charger on it.

When I return next month I'm going to assume the battery is flat.

I have researched the forum and found different answers for my question:

Can I jump start the vehicle or do I need to first have it recharged using an AGM settable charger?

If I have to have it recharged I'll need to remove the battery and take it to my indy MB facility.

Thanks in advance!

 

I would assume you could jump start it from under the hood using the pos post and neg grounding point. It would be the same as a dead battery after leaving your lights on. You probably will get a whole mess of lights on the dash until the voltage gets closer to 12 on the battery.

 

Reconnected the main battery and it started up right away after seven months!

Had to reset the sunroof, clock, and some other things, but all in all an easy wake up.

I do have a battery icon in the dash and took it into my indy MB place. After hooking up to the STAR system it indicated the small auxillary battery needed replacing. After the initial warm up I did notice it was a little slow going into gear the first time but ever since then all has been fine.

The tech told me there was a slight chance that the small battery would recharge while driving over the weekend. I have an appointment Monday morning in case the small battery does need replacing.

 

The auxiliary battery did not recharge and so went to the MB dealer and picked up a new one (needed to pick up some quarts of oil for both the ML and the wife's C350). Brought it back to my indy MB shop and had them replace. The main battery had to be removed in order to access the auxiliary battery.