Posted 30 December 2013 - 08:12 PM
I once had a random parasitic battery drain on a car. About 2 - 4 times a year, the battery will go completely flat (< 12v when measured with a multimeter). The drain will go away after the car is restarted. Sometimes the drain will go away even when the battery is bench charged and reattached to the car, without restarting. Knowing that unless the perpetrator was caught in the act, the auto electrician will just take my cash, promise all is well but problem will still be there. Drove me insane for 2-3 years.
One day, the culprit was finally caught in the act. NRMA guy arrived and his instinct is to jump start the car and check the charging system. Instead of that, I asked him to hook up the jump start pack and use his current clamp to check for drain. Sure enough, the alternator was draining the battery. So car is jump started and off to the auto electrician. Even with that information, the auto electrician said it took ages to identify the problem when he bench tested the alternator. I probably should have just called a tow truck.
Anyway, hope it is only the battery and not something more annoying.