Split Charge System Help

[Bigchaser]

Hi Guys,

I totally confused, the more I read the worse it gets…… I want to wire in a very simple split charge system to power a Waeco CF 50 fridge in my Land Rover Camper, to allow the fridge to run all weekend while I’m away hill walking and not drain the starter battery.

I have been told the simplest is a voltage sensing relay, just 3 wires to connect. What size cables should I use to connect the two batteries? Does it have to be big cable like the cable from the battery to starter motor, or can it be smaller?

I need your advice guys???

 

[Firefox]

Use a smartcom relay Ring Smartcom Relay - Demon Tweeks

Use 40-50A cable 5mm2 or 6mm2 wire, and a 25-30A inline fuse

The smartcom relay has a fridge connection.

There will be 5 wires to connect. Wiring diagram comes with the relay.

 

[ellisboy]

If you have a second battery then wire the smartcom to charge the second batt while driving.hard wire the fridge to the 2nd batt using 6mm cable and a fuse.then you can still drive away when you get back.Compresser fridges use quite a bit of power.Theres a diagram of a split charge system using a smartcom relay on my build blog.

 

[FULL TIMER]

One of these 0-727-33 DURITE 12V 140A SPLIT CHARGE INTELLIGENT RELAY | eBay would be your best option one wire from you vehicle battery pos terminal with an 50 amp fuse inline,one wire of the same size to your secondary battery pos terminal, one thin black wire from the split charge relay (already fitted) down to earth or van battery neg terminal, wire to fridge via an apropiate size fuse from secondary battery, wires from and to split charger around around 6mm sq, wire to fridge around 2.5mm sq

 

[hextal]

Possibly overkill - but would you not have to size the cable based on the alternator rating (even when just wiring between vehicle and leisure batteries)? Just thinking that if both batteries were fairly flat for any reason then the alternator would probably be dishing out close to its rated output capacity.

 

[Bigchaser]

Thanks for the info Guys...

 

[ellisboy]

If a smartcom relay is used then There is no need to touch the alternator wiring.Heavier gauge cable is needed to avoid voltage drop if the is a distance between starter and second battery.Ive used 16mm welding cable for mine,it's cheaper to buy in precut lengths on eBay .