FIXED - ECO start/stop not working on Mercedes E350 W212; was NOT the auxiliary battery in the trunk

The Start-Stop ECO feature on our E350 (W212) stopped working. It was not a weak auxiliary battery (2115400001 or 0009829608) in the trunk. The problem turned out to be solved with a new main battery (0009822108). The main battery initially showed a low voltage reading of 12.1V and my external charger showed the battery at 55% charge. I charged battery to 100% and then took it to be load tested at local auto parts store. They confirmed battery was weak and delivering less than 50% of rated Cold Cranking Amps. ECO problem resolved with new main battery. I also upgraded the battery from original H7 to a larger and more powerful H8 which easily and properly fit into the existing battery tray at the same price as the H7..

Видео FIXED - ECO start/stop not working on Mercedes E350 W212; was NOT the auxiliary battery in the trunk канала YuDaMan