2007-2012 Mercedes-Benz GL450 GL550 Auxillary Back Up Battery 000000004039 OEM For Passenger Car

The auxiliary battery for my Mercedes Benz GLS550 was the perfect fit, easy to install and resolved my battery error issue immediately. I highly recommend purchasing this if you get the replace auxiliary error message.

Battery life good as is the value for money

Arrived promptly and worked perfectly. Highly recommend.

Perfect replacement for my 2013 E-350. Replacing it was way harder than it should've been. But, that was no fault of the batteries.

This item got rid of the Aux Battery error on my 2020 A35. Looks very similar to my original battery (original is in the left on the photo).It arrived with 3 different instances of external casing damage on it though (see pictures), so either it was shipped like that or it wasn't packed very well and it happened in transit.

Perfect fit!

I had never even heard of an auxiliary battery, but this car has one. The car is 13 years old and I imagine it's original. Apparently it controls the electronics and when the warning comes on, you're not supposed to drive it, but we did for about 5 days. It took about 45 minutes to replace. It's located under the left edge of the dash and accessed by a panel you remove which is above the driver's knees.. This replacement battery looks identical to the original.

It was as advertisedIt solved my car problem