Drained 12V Battery in a hybrid or EV? The Physics of Parasitic Drain - and what to do about it!
I was contacted by ITV and subsequently filmed on this subject, but the final footage was cut massively short by time, so I thought my notes would be helpful to others in full.The trigger point for recording was instances of people being locked out of or locked into hybrids or EVs when their car's 12V battery had run too low. I did a video on 12V battery drain a couple of years ago and it had come to the attention of the ITV reporting team. My response Despite the concern, there really shouldn’t be any alarm from a safety standpoint. All car makers put in place failsafes for such an eventuality. E.g. when electronic door latches don’t work on a Toyota or Lexus hybrid, from the inside you can pull the door opening handle twice. The first pull unlocks a mechanism and the second pull physically opens the door latch. And from the outside, you can use the (usually hidden) mechanical key included in every key fob. This fits into the keyway on one of the front two doors. O...