Club 80-90 Forums

Hi

I am planning to put in a leisure battery, mains hookup, battery charger and a mains inverter. I know about the relay that should be used to isolate the leisure battery from the starting battery when engine is not running...

But what I don't know is if there are any recommended ways to wire it all up.
I have had a stab at designing a circuit.

I should probably add a relay which disconnects the charger when the engine is running (to protect the alternator) and I guess a fuse on the hookup somewhere?

is there anything else I have missed...?

[img:720:540]http://i-luv.info/Slide1.GIF[/img]

The black lines are for 12v DC power.
Blue is also 12v DC but only for switching the relays, ie. low current
Red is 240v AC power.

I have designed it with convenience and battery life in mind... The idea is that the mains sockets in the van can be connected to EITHER the external hookup OR the inverter (but never both)... and the battery will be connected to EITHER the inverter OR the charger (but never both). Additionally, it would be nice to be able to turn the mains off at any time from a single place, and for the charger to only be connected to the battery when it is actually producing charge, otherwise it will slowly drain it.

Relays 1+2 control the charger circuit and relays 3+4 control the inverter. The switching circuit does not allow 1+2 to be switched on at the same time as 3+4.

The mains mode can be switched between the following 3 modes:

EXT = use external hookup
[img:720:540]http://i-luv.info/Slide2.GIF[/img]

OFF = no mains power at all
[img:720:540]http://i-luv.info/Slide3.GIF[/img]

INV = use the inverter
[img:720:540]http://i-luv.info/Slide4.GIF[/img]

I've something similar in mine.

My inverter is wired in to the mains sockets through the RCD it differs to yours by the fact it is a separate system... ie the battery is not connected to the alternator... it is charged when a charger is switched on manually when on hooky. purely for the reasons you stated.
It has been very useful to always have a 230v supply for any thing but heat.

I am however moving away from this set up, and finding a 12volt alternative for most things, as it seems these days, they are cheaper and easier to come by.

nice diagrams by the way.

cheers... powerpoint can be pretty good for circuit diagrams, as I have just discovered

in theory it's a good idea, be sure to use double pole isolating relays and be aware of the power loss of the invertor, though more recently they are becoming more efficient!

it wouldn't supprise me if this was an option on the larger american motorhomes!

good werk!