Battery drainer

[maxi_77]

There can be all sorts of causes for battery drain, though radios are perhaps one of the more common. I have had a duff relay kill a battery before I found out what the problem was. Things plugged into the lighter sockets can also draw more than you think too. At the end of the day you need to put an ammeter in the affected battery circuit with everything off, the 10A circuit in a low cost multimeter worked for me, then disconnect the circuits off that battery one at a time, and when you find the guilty one then you can work down that circuit to find the cause. Remember it can be partial shorts in the wiring as well as faulty kit. Just guessing and randomly isolating things will take too long and could cost you a battery.