Double wiring loom??

I have a "double wiring loom" for the batteries on my Autotrail. Do both pair of wires come from the same split charger unit, either being charged from the alternator or when on hookup?

I am trying to add a third leisure batterie to my double set up.....three new batteries....with a view to adding a 2000w inverter, in the future.

I have 220w of solar running through a mppt controller. This is wired direct to the batteries and not through the wiring loom as previously mentioned.

Just wanting to make sure that the existing wiring wont be affected by the inverter once fitted, because the cables to link the batteries and connect the inverter will be "a lot" bigger!!

Thanks

PJ'S

Your leisure batteries should be wired in parallel with heavy(ish) cable.
Your inverter will also be connected to the +/- side of the leisure batteries with good heavy cables as the amperage draw on a 2KW inverter on high load is high, therefore quality cable is required.

I'm not sure the cables you are seeing are both from the split charge relay.
There is usually one cable that charges the leisure battery only when the engine is running. This is wired in such a way that the starter battery cannot be drained when the vehicle is stationary with engine stopped.
The second cable COULD be a supply cable from the starter battery to the control panel in the habitation area where you select which battery supplies power to the habitation side. This is only used in a case where your habitation batteries are exhausted and WILL run your starter battery flat if used for prolonged periods.... it is my belief that this shouldn't be used unless absolutely necessary.

It's a good idea to have a solar controller that charges both leisure and starter battery. I've mine programmed to supply 90% of the solar charge to the leisure batteries and the remaining 10% to the starter battery. This keeps the starter battery charged if parked up for any length of time.
Also, a MPPT controller is more efficient than the PWM type.

Three batteries and a 2Kw inverter? Am I missing something?

Amps !