Battery keeps dying

[Daveo]

My car battery keeps dying on me if I leave the car overnight. It has a grand new battery in it no older than 3weeks, the car has got an aftermarket alarm fitted to it and recently I fitted a new cigerette lighter in the car, so could it be the new cigerette lighter that's causing a draw on the battery?

[brainsnova]

Is the alternator charging the battery and if nothing's plugged into the cigarette lighter then it won't use power

[Novasport]

Wouldnt have thought the cigar lighter would drain the battery unless there is something plugged into it that is constantly using power.

[therealnovaboy]

If there is a wiring fault when you fitted the lighter it will pull current through the fault. Pull the fuse for the lighter and see if it still drains the batt. could be a duff batt but unlikely if its new. Quick check would be to put a voltmeter across the batt and check the voltage drop when you start the car. it shouldnt drop below about 9v.

[meritlover]

start with the basics.
check the alternator is charging (14.5v) approx.
test the battery is ok.
follow the fault finding technique as shown in the thread below.

[Daveo]

I've put a voltmeter across the batt and the alternator is working fine

[meritlover]

... then your search continues

[L14MNP]

... then your search continues

Mine however does not. Marry me, meritlover.