Leisure battery ran down and altenator didnt recharge??

martyc5674

Hi there,
just curious as to what might have happenned here.
Weekend before last ran down my leisure battery overnight...anyway drove home for an hour and a half the following day and battery took zero charge all the way home, (electric step sticking out all the way home!!)
Anyway i thought i had goosed the battery which is only a year old but once i plugged in it took a charge staright away and seems to have held it since(was away last weekend in it)
Im pretty certain the altenator normally charges my leisure battery but for some reason on this occasion it didnt...there a logical reason for this...did i run it down too much??
Marty.

stapeler

If your altenator is okay(giving 13-14volts on the main battery) then it's possible that your split charge relay may be failing. It toggles the charge between main battery and leisure battery. Probably best to put a meter on the leisure battery with the engine running to see if it's charging.

dowtchaboy

Yes - it's worth checking EVERY wire running to and from the leisure battery and the engine battery. I had a similar problem and found it was a loose connection (and it was not obviously loose) from the alternator to the relay. In particular check inside the crimped connectors.

Note that the leisure battery will not show charging voltage until the red light in the dash has gone out - ie you will have to rev the engine a bit until the red light (with the battery symbol) goes out - that's when the alternator starts to charge the batteries (and you can stop revving then!). You can check the voltage with a meter or you should have a meter in the van someplace with a switch to look at leisure or engine battery voltage.

Any loose or poor connections on Earth wires can cause odd, head-scratching, problems too.

Think this very problem was discussed on another thread here - have a search.

martyc5674

Cheers lads,
Yeah its seems to be working fine but just this one time when i completely drained the battery it didnt seem to want to take a charge from the altenator...
Ill stick a multimeter on it tonight if i get a minute!
Marty.

martyc5674

Turned out to be a 30A fuse blown!!...battery hadnt been getting charge for quite a while by the looks of it and i tend lately to run the fridge on battery whilst driving(which was killing my battery)

Is that what the split diode/relay does so?..decides which battery to send the charge to?.I had always assumed it just prevented one battery topping up the other etc etc.

When i start the van now it immediately starts charging the leisure battery.(must check tonight if its also charging the van battery)

Cheers

Aidan_M_M

It stops the camper draining the engine battery when you turn off .