Waking up to a flat battery is a classic H247 complaint. We walk through the likely dozers-and-sleepers check, and how to decide if it’s safe or needs attention.
First, Be Fair to the Battery
A GLA H247 that's a few years old will often flatten overnight because of a system that won't shut down, but a weak original battery can also look identical. Before blaming your drain, have the battery load-tested. On many H247s, the battery management module needs to 'see' a healthy battery before it allows electronic modules to sleep. If the battery checks out and you've confirmed a parasitic draw (typically something above 80-100 mA after about 30 minutes with the car locked and doors closed), the next step is patience and a set of fuse pulls.
