The 2007 ML 63 Japanese import I just acquired had remained stationary for a week, connected to a trickle charger while I was familiarizing myself with the new head unit (still in the process...), but had not been operated otherwise. Last Monday, I attempted to deliver it to Terry Gates for tailgate repairs, but the electrical system was completely nonfunctional—no unlocking, no illumination on the dashboard, and the key would not turn in the ignition. I effortlessly jump-started it using the other ML, then drove it to Harrow, which took around thirty-five minutes. It was not charged throughout the period it was being serviced, and I retrieved it on Friday. It began satisfactorily.
The importer asserts that they installed a new battery, and I believe this assertion to be accurate. The inquiry is if a brief duration of somewhat more than thirty minutes suffices to totally recharge a depleted battery, or whether the electrical system is designed to deactivate at a certain voltage to avert total battery drain.