Will Hunt

I have a 08 s550 I have gone through 6 batteries 5 autozone 1 walmart within 24 hours they will drain to 5 volts it only draws 170 millivolts when off and locked I have tried to pull fuses and unplug the seat module none made a difference in amp draw I got no fault codes can't figure it out.

artim808

Which battery is giving you trouble? Starter battery in engine compartment or main battery in trunk?

Will Hunt

the consumer battery in the trunk

SilberGrau57

Check and re-check all battery terminal connections. Clean corrosion off all connections. Make sure the negative ground cables are securely fastened to the chassis for both batteries. There might be a sequence of disconnecting battery terminals--in mine it is 1) negative terminal consumer battery, 2) negative terminal starter battery, 3) either positive terminal can then be disconnected next...Re-attach in the reverse order: fit the positives back, then the negative starter battery and finally, the negative consumer battery. Read it in your manual.

Polar Bear

When you disconnect the consumer battery, do you disconnect remove the bolt securing the ground cable to the chassis, or remove the terminal directly from the battery? Do you see excessive arcing when you reconnect the terminal?

Will Hunt

I remove it from the battery terminal and I do notice arcing sometimes.

Will Hunt

I put a 18ah jumper box on it for 19 hours and it still held charge.

Will Hunt

I left a multi meter on for an hour and it fluctuates between 10-120 milivolts.

Will Hunt

Solved the tel-aid module went bad.

pmercury

iTrader: (2)

here

https://mbworld.org/forums/sl-class-...08-2009-a.html

Will Hunt

Is this a free repair?