A dead battery every morning usually points to a module staying awake. Here’s what we check first on a GLS X167 and when it’s safe to drive.
Why a GLS X167 battery dies overnight
A parasitic draw is current that keeps flowing after the vehicle should have gone to sleep. On many modern Mercedes-Benz models, normal sleep current settles around 20–50 mA after 20–60 minutes, though some X167s take longer and certain modules can wake briefly for legitimate reasons. If your battery is flat by morning, the draw is likely above spec—or the battery itself is weak and cannot hold a charge. Start with a proper battery test, charging voltage check, and a scan for stored faults. Also look for aftermarket dashcams, radar detectors, GPS trackers, phone chargers, or alarm accessories wired to constant power; these are common and easy to rule out.
