Leisure battery worries

[Jamesd]

Hi all, I had a LB fitted by a local garage and one of things I wanted was the radio and the 12v sockets to work without having to have the key in the ignition. This was sorted - by the garage guys doing some soldering in the fuse box (sorry if my description sounds ridiculous - I'm not that technical). The system is automatic in that I don't have to push any buttons to switch between the main battery and the LB. Anyway the concern I have is that the glow plug is possibly drawing from the leisure battery - as when the LB has run down, eg by leaving the 12v cooler on, the glowplug indicator light stayed on then flashed. Also I suspect that the engine cooling fan is drawing from the LB. Is this ok? My thinking is that these things should draw from the main battery and its a worry to think the glow plug wont work if the LB is flat. The van still starts fine when the LB is flat.
I'd appreciate any words of advice.

ps if you are driving along, shouldn't all the electrics be drawing from the main battery - leaving the LB to be charged.... so many questions, I should take an autoelectrics course!
James

[draper3000]

evening...only had my bongo for 25 hours...Woo..

But before this I had a VW...

As far as I know..the vehicle only charges the mian battery when running, but some appliances, lights in the back or what ever is rigged will still run off the leisure battery. Once the main battery is charged relay switch will switch over and charge up the leisure battery.


...

[bongolow]

It sounds like yours is wired the same as mine, which was done by Manchester Campers. I've also done the mod in the fuse box to get the radio, sockets etc. working from the leisure battery.

There is a relay which connects the two batteries together when the ignition is on, so both batteries are charging when the engine is running. Once the ignition is off only the leisure battery is drained, so you needn't worry about the glowplugs or the main battery being flattened. I also have the flashing glowplug light when the leisure battery is flat and I think it's just wired into the light circuit to give some warning that there is a problem. The relay burnt out on mine so the leisure battery wasn't charging at all - they had fitted a tiny relay rated at 15 amp even though it had a 30 amp fuse in series with it. The flashing glowplug light stayed on even when I was driving.

I'm told the theory is that the main battery, being connected with short hefty great thick cables compared to the longer, thinner cables on the leisure battery, takes nearly all the current when you start the engine, even though the two batteries are connected together once the ignition is on.

Anyway, I've had no trouble with glowplugs or starting when the leisure battery was flat so don't worry about it.

Edit. Just to clarify a bit - although the glowplug LIGHT is used to give a warning indication if there's a problem with the leisure battery, the actual glowplugs are fed from the main battery, not the leisure battery. That's how I understand it anyway.

[dreamwarrioruk]

if they didnt fit a voltage sensing relay to the bongo this would account for the glowplug light. ie they fed it direct from the alternator.this can cause a problem with the bongo electrics as the voltages are very sensitive and a small drain such as the relay will result in a constant glowing glowplug warning light.

[Jamesd]

thanks all for the advice - takes some of the anxiety away. I will look into the voltage sensor though, I'd have thought this would be part of the package with the relay, but I'll ask the guys at the garage anyway.
Cheers
James