bobterry99

It would only cut-in the moment the key was switched from position 0 to position 1 and would de-energize if the engine is not started within 30 seconds.

That's good to know, Rodney. Your record of success is extremely compelling.

There is one thing that is a bit odd to me. The owner's manual says to make the final connection between the batteries after the donor car's engine has been started. I would think voltage spikes would be less if all connections were made with the engine off. I googled articles on jump-starting, and all of them state to complete the battery connections before starting either engine. I can only surmise that it really doesn't matter either way...

Rudeney

So, if the consumer battery is dead, and the starter battery is too weak to power anything, including the EIS, then is there a way to "boost" the consumer battery?

The only reason I can think of for having the donor car started is that if the SL's battery has a dead cell(s) then it could draw down the donor batter to the point that it might not start its own engine. Honestly, if you just do a nice, smooth connection with the jumper cables and don't panic and "stutter" when you get that little spark, then there's little chance of spikes.

bobterry99

The M-B training document states that the starter battery powers the starter motor armature and nothing else, but that is not true. The starter battery can also power the N82 vehicle power module. Therefore, in the case where both batteries are weak jumping from the starter battery can start the car.