Club 80-90 Forums

The old Voltronic charger in my westy died and took out the leisure battery attached at the time. Having just changed the old JX diesel for an AGG petrols (2litre Golf GTi) so I thought "What the heck - might as well look at the camper electrics now as well!". Since I replaced the RM123 fridge last year with a new Waeco unit and the Eberspacher had died (even before I lost the diesel tank!) it was time for a rethink. I will be fitting a new Propex underslung heater in due course but my immediate concern is the new twin leisure batteries and the mains hookup. I have a solar panel on the roof which provides some top-up power but my thoughts are this:
Do I put a new smart charger (something like a CTeK) in and leave the leisure batteries on float (i.e. continue to draw internal power from the batteries, but keep charging them from the mains all the time when on hookup?
or,
Put a 15-20amp switched mode power supply in with a changeover relay so that when mains power is applied the power supply puts out 12 volts, disconnects the leisure batteries from the internal wiring and supplies all demand directly.

Any thoughts, pros and cons? I am still in planning stages. Have repaired the water level sensor and control display, add a few more USB sockets to replace the old 12v cigar style sockets, rewire all the internal lights (which are now LED anyway) to run from the leisure battery rather than starter, thinking of a a CTEK DS250a direct charger to replace the split charge system, take care of charging the leisure batteries, handle the solar power inputs etc all in one box and will essentially remove the old camper wiring and replace with something a little more direct (Have you ever worked out where your fridge gets power from - too many relays, switches and wire to make sense!

Steve

One point to note - Waeco CR50 fridge is VERY fussy about cable length / SWG and number of switches / fuses / connections it goes through. Doesn't take much to get the power warning light to come on whereupon the fridge stops fridging! mine used to do it even though my leisure battery was still at 12.5V! Have since re-wired it properly and all good now.

I only run the fridge continuously from the mains when on hookup.
Everything else runs off the leisure batteries which get charged from the mains when we go to bed.
You could float them if you like, though you might want to check with CTek that it won't confuse the charger's program.
I don't see a need for 12 power supply and changover relay.
Hope that helps.

Fridge is 12v only so I need a 12v power supply, either specifically for the fridge on mains hookup, or for everything. But thanks for the info re the wiring.

ah yes, i see the need for the 12v supply now, My coolbox/fridge has one built in and I've just wiried it for automatic changover.
In your situation I think i'd be fitting a dedicated fridge 12v supply right enough, with auto changover relay.
Putting thet much load on the battery when it's charging might mean the charger can't keep up with demand.
I aslo have a voltage sensitive relay in my charging system that has an output for the fridge so it only runs off the alternator when the engine is running (unless i'm on hookup, then it's on mains)
I think some CTek units have it too.

I can manually switch the fridge to my second leisure battery by swapping fuses if I'm parked up and not on hookup but I have to be carfull not to deep discharge the battery.