battery dying again

[peanutcrusher]

for some reason i leave my van for 2 or 3 day without driving it and the battery in so flat that the cab light will hardly light up and the centrol locking does not unlock all the doors. got the van to start i'm hoping that the van did not draw for the second battery. lost all the settings on the stereo
anyone got any ideas i have an mp3 head unit which using a usb pen memory stick so i can sort of except the the second battery dying in a way but not the main battery.
anyone got any ideas where my problem may be.

[mister munkey]

First thoughts, is it a Liddle/Aldi stereo?

Some of them seem to cause a permanent drain . . . .

[peanutcrusher]

no alpine not cheap in anyway

[westonwarrior]

May have to do a draw test on the battery

put a volt meter in line and measure the currant then remove fuses or items like stereo internal lights etc until you find the bad circuit

[peanutcrusher]

i thing my screen are drawing so i have pulled the fuses out of them but i'm still not to sure why the main battery keeps dying

[Yamaha]

Bad alternator diode/diodes?

Mike

[maxi_77]

I had this problem and after the second battery had been fatally damaged by being completely flattened I discovered that I had a faulty spot light relay that had a weak short to earth. You need to put a reasonably sensitive ammeter in series with the battery when everything is of and the key out then see what the drain is, if it is more than a few milliamps for radio, clock etc then you have a leccy leak. The try pulling each fuse in turn to find out which circuit has the fault. Then all you have to do is find where on the circuit the problem is.

Good luck you may need it, it took me a few months to get to the bottom of it.

[eckerB]

It could be the charge relay has gone faulty and the aux battery is drawing current from the start battery when the engine is off.

[maxi_77]

It could be the charge relay has gone faulty and the aux battery is drawing current from the start battery when the engine is off.

Only if something is already draining the aux battery, unless it is knackered no battery especially a half decent leisure battery should self discharge to those levels inn that period of time. There must be a partial short to earth somewhere, or something being left on, or a fault of some kind in an always live circuit. Of course the problem could be compounded by the reality that with regular deep discharges the starting battery is f*cked to use the technical term.

[gasace]

I have an ongoing problem with battery drain, the main cause is the heater staying on when the key is switched off. Now that I'm aware of this I check every time to make sure the heater has switched off. Also the leisure battery drained as well the first tome it happened, and I think the fault is with the ignition switch, which is keeping the heater and split charge relays on and draining both batteries. So far my local auto electrician has not been able to find the fault and has now stopped looking. I have not had time to have a proper look yet, and as long as the heater goes off the bongo starts OK. Is your heater manual or auto? With the auto it is easy to see if it is off.