12 Volt Setup Help

If you want to keep it simple i would put one x 120amp AGM battery (2 if you have room and money but not necessary) in the tray of the highlux immediately behind the cab and invest in say 180watts min of solar panels.

Again keeping it simple the main and secondary battery can be wired in parallel and you can fit a low voltage cutout device at the fridge to cut power to the fridge when voltage drops to around 12v.

With this set up you will always be able to start the vehicle and the fridge will draw on the combined capacity of both batteries,your altinater will hapily charge both batteries when you are on the moove and the solar will top up batteries,if no sun for a few days run the engine on fast idle for approx 45mins twice a day or go for a drive.

Others will suggest electronic cut out devices and dc-dc chargers and they have their place in other circumstances,but the above is simple,low cost and works.

!80watts of solar can be purchased under $500 these days.

You don't need a 50A charger with the load you describe, and with AGM's you could even damage them as they often have a maximum charge rate of 20A or so.

Get a 25A charger and put the rest of the money into 160W of solar panels and a good MPPT controller.

Hi RR,

As well as the replies you receive here, you would do well to read a couple of the articles on this site about auxiliary battery power such as "Battery Power". or "Electricity for Camping".

As you seem to know, too much charging current can damage AGM batteries so limit it to 25 amps per battery.

Thanks for the advise guys. Certainly gives me a few ideas and things to think about.

Pepper2, so is it quite OK to connect my car battery to the 1 or 2 agms I get?

Is a duel battery system for the car a good investment or not really required?

Cheers

OK RR, here is a plan for you.

1) Put a 100+ amphour AGM battery in a battery box in the tub.

2) Connect this to your alternator at the cranking battery terminals with at least 16mm2 twin cable. Put an 80A fuse in the +ve of this cable at each end to guard against possible short circuit.

3) Place an automatic isolator (suggest Redarc SBI-12) in the +ve of this cable at the cranking battery. This isolator connects the AGM for charging but isolates the cranking battery from supplying the fridge etc when the engine is stopped and ensures the cranker is not drained. The isolator also prevents the starter motor from drawing current from the AGM and so damaging the cables and fuses.

4) Connect a 120W solar panel (portable folding type) to the AGM via an MPPT controller. This should be sufficient to maintain your auxiliary load but if necessary you can always run the engine on fast idle for a while or go for a drive. No real need to lug a portable gennie.

5) Supply your fridge and auxiliaries from the AGM through appropriately sized fuses.

Now, there are all sorts of options and variations to this setup but the above is about the simplest and safest for your expressed needs.
One option of value is to use a Redarc BCDC-1220 isolator/charger instead of the SBI-12. This not only serves as an isolator but also as a 3-stage charger to better maintain the charge to the AGM but it does cost more. Or for a bit more $ use a Redarc BCDC-1240 which incorporates an MPPT controller for the solar input.

Some may propose and use really simple arrangements such as directly connecting a second battery to the cranker with no isolator and no fuses and get away with it without setting fire to their vehicle....... but good luck to them, they are taking risks that I am not prepared to do.

As has been said, for more info take a look on the ExplorOz site at the Battery Power article.