I have a battery issue. On two seperate nights my fairly new quality battery went flat. My used but good standard battery (this battery has its own puzzling history) but it survived 2 nights without going flat between the 2 failures of the newish battery...Clearly the newish battery was faulty...But no the used battery has gone flat overnight now.
Ok so something is draining the battery. I have purchased an amp reading multimeter and connected it in series between negative post and negative wire post clamp. Found of course high amperage but as the car went back to sleep the current dropped away to below 50mA. So no battery drain.
Clearly the drain is intermittent...how could I pin it down as touching the car could be enough to cause any erroneous drain to stop and it would be disguised by normal current draw on touching the car. A bit like Schrodinger's cat, looking to find the problem could hide the problem. The outcome is extremely uncertain.
Any clues as to how to pin it down? I have a NOX sensor 2 problem which I think may be electrical in the car rather than the sensor as I have swapped sensors between 1 and 2 positions and it is no.2 that keeps showing faulty also fault from Adblue control.
I don't know if these are connected or if it is coincidence. Anything my MUCAR OBD11 could point too assist ?