Leisure battery keeps going flat

Hi have a leisure battery optima yellow on split charge keeps going completely flat after a few days when fully connected, but if left unattached will stay 100% charged for weeks. Vehicle is left in garage and only used on trips. Mechanic checked connections for shorts couldn't find anything. Any ideas as has been like this for ages and going to Africa in a three weeks or so. Thanks

try disconnecting alternator

thanks for reply jm interesting to know what you are suggesting might be amiss.

Diode pack on alternator for a guess, see if your battery light is lit, you obviously have a drain somewhere.you could set a multimeter to amps and connect in series to your battery and see what drain you have

Mine came from the rear window heater, now unpluged never to be used again.

Battery light not lit and engine battery ok, there is a wire from each battery to alternator but leisure battery goes flat after a couple of days whilst car remains in garage.

Are you using a split charge system ??

Daz

Yes

Might be an idea to charge both batteries - leave them both connected for a couple of hours then go out and feel if the alternator is warm

If it is thats where your current is draining too

Daz

are the batteries isolated from each other?

If not, one can discharge the other.

^^+1

The Mad Hat Man said:

are the batteries isolated from each other?

If not, one can discharge the other.

Click to expand...

Thats why i asked if he was using a split charge - as he said both batteries were connected to the alternator

Daz

Yeah - but we know "split charge" systems can vary considerably in their complexity.

even if separated by a relay - if that fails then back to square one. .

Exactly!!!

Daz