Question: I have installed a LFP battery in my car. But when I came today to the car, the car was completely dead and all electronics stopped working. What is wrong?
Answer: What you describe may happen with the car. When the car is parked, over some days, then some equipment will discharge the battery to complete emptiness (full deep over-discharge).
This may happen when the small “inside” lamp is by mistake left “on”, or when the door is not closed properly.
It may also happen that the radio was left “on” – but silent, or some other equipment drained the battery (e.g. alarm system that turned on for some reason).
In some cases the driver may accidentally forget the main headlights on, and the battery will be depleted just in a few hours.
Also the internal electronics (e.g. the control unit of the car) may have some problem and it may stay on running with some 10W to 50W of continued consumption. This many discharge the battery on a day or two.
Simply there may happen many reasons why the battery in the car becomes suddenly (over some days) depleted to fully empty.