mdorough1

This light just came on, can I safely drive it a few days until I can get it to a shop?

Lolxa

You can drive the car without an auxiliary battery and its easy to change out too. Only cost me an hour of work and a new 20 dollar battery

kajtek1

W212 do have 2 aux battery systems and they do totally different things.
I prize MB for actually thinking for the owners and on lot of instances - protecting cars from owners stupidity.
So if the warning comes in yellow, that means you can continue to drive for now. Sometimes the message will tell you for how long.
But if the warning changes to red warning, be ready to immediately pull over and turn the engine off.
If you ignore that, the car can do it for you and that seldom is pleasant.

Royce118

You can drive the car safely. The auxiliary battery is used for eco start stop function as well as the brake hold function. As far as I recall, the rest of the car will function just as fine.

thefisch

OP, do you have a 2010? If so, the aux battery is for the electronic transmission shifter. https://mbworld.org/forums/e-class-w...placement.html

If you have a 2013 or later then it is for the eco start/stop feature. Different location and a much more expensive battery.

wally AMG

Save yourself some money

https://www.ebay.com/itm/Mercedes-Be...item1c8dd34a0f

change battery is very easily, dealer will charge you for diagnostic, remove panel B, remove panel C, unpack battery, disconnect battery, install battery, battery disposal, reset here and there, etc, etc, not to mention have the car for 4 hours !