Dual battery next to fuel tank in ute?

[hako]

The wiring setup will run off the alternator, there wont be a chance of two flat batteries that I know of, my mates going to help me with this part.

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If you run it off the alternator it still will not be isolated from the battery - the alternator is wired direct to the battery and you will be drawing power from both batteries with the 'charge' switch on. 4X4 shops sell 'isolators' but they cost more that you planned to spend!. Wiring a relay into the ignition circuit can be done for next to nothing.

Re sealed batteries - here in Toowoomba a lot of battery places like Battery World sell car size sealed batteries from electric wheelchairs/gophers (like what the oldies drive) for $35 secondhand. They are only one or two years old and are replaced well before they fail to remove the chance of them failing in use.
Maybe you could check this out in your part of the world.

 

[Tom_1569]

If you run it off the alternator it still will not be isolated from the battery - the alternator is wired direct to the battery and you will be drawing power from both batteries with the 'charge' switch on. 4X4 shops sell 'isolators' but they cost more that you planned to spend!. Wiring a relay into the ignition circuit can be done for next to nothing.

Re sealed batteries - here in Toowoomba a lot of battery places like Battery World sell car size sealed batteries from electric wheelchairs/gophers (like what the oldies drive) for $35 secondhand. They are only one or two years old and are replaced well before they fail to remove the chance of them failing in use.
Maybe you could check this out in your part of the world.

Ill have to check with my mate, but we MAY be using an isolator (using an old setup oout of a landcruiser), he showed me his and there was a relay and another cylinder type thing to go with it, but wiring does my head in so I just agreeed, and Ill leave it to him lol. But if thats not his plan Ill make sure an isolator is inplace so I dont flatten both batteries, caus that wont be so fun lol.

Would a wheelchair battery be adequate for a few days camping? I might just buy another 660cc Sealed battery, funds depending.

 

[Tom_1569]

Ok, been doing some more planning to get this happening soon.

Turns out my mate is using an isolator, just calls it something different, and doesnt have a working spare.
Im looking at getting this ONE, and following the typical wiring diagram provided, but on the earth for the isolator, run that to a switch in the cabin. Or alternativly run THIS ISOLATOR.

Next question is, what Gauge wire do I need to run, from Main battery to Isolator, and Isolator to Auxillary?
With all going to plan, Ill get most of this in (minus the sealed battery) in two weeks or so.

Also going to use THESE PLUGS.

 

[hako]

Maybe you are getting away from your original intention which was a battery to supply camping needs at minimal cost. Once you instal an isolator and weatherproof plugs with all the associated cabling plus a new 660CCA battery you are looking at a permanent installation which is no longer simple and cheap.

I'm not trying to tell you how it "should" be done as I don't know your circumstances, but if were doing this again I would:
Obtain a 2nd hand battery - preferably sealed, maybe ex wheelchair - CCA not important and at least the same size as a Commodore battery so it's not too heavy. I'd make a box for it - chipboard or whatever just to protect it if it slides around in the ute tray.
I'd then but a double cigarette lighter adapter from SuperCheap or wherever (under $10) and wire it direct to the battery with a 20 amp fuse inline. This allows me to plug 2 appliances in.
To charge the battery I would normally keep it fully charged at home with a battery charger (under $20) because the best way to kill a battery is to let it sit whilst flat and if I'm only camping every 3 months I know it will happen.
To charge the battery whilst driving I'd run a pair of cables from the battery thru a hole drilled thru the back of the cabin and then terminating in a plug which I can stick into the car cigarette lighter so the battery gets a top-up charge when driving. The cable can even be household 2 or 3 core wiring - it only needs to carry no more than 10 amps. At the battery end I'd use simple alligator clips onto the spare battery.

If I thought I would not need to charge the battery driving to my campsite as the battery is already fully charged from being on charge at home I wouldn't even bother with the complication of wiring it in - just have the double cigar lighter connection.

The above is just skimming over what is needed. I like the old K.I.S.S. principle.

But in the end it's your choice and you need to be happy with the design.
Here is a link to a good site:
Caravan & Camper Battery Charging @ ExplorOz

 

[Tom_1569]

Maybe you are getting away from your original intention which was a battery to supply camping needs at minimal cost. Once you instal an isolator and weatherproof plugs with all the associated cabling plus a new 660CCA battery you are looking at a permanent installation which is no longer simple and cheap.

I'm not trying to tell you how it "should" be done as I don't know your circumstances, but if were doing this again I would:
Obtain a 2nd hand battery - preferably sealed, maybe ex wheelchair - CCA not important and at least the same size as a Commodore battery so it's not too heavy. I'd make a box for it - chipboard or whatever just to protect it if it slides around in the ute tray.
I'd then but a double cigarette lighter adapter from SuperCheap or wherever (under $10) and wire it direct to the battery with a 20 amp fuse inline. This allows me to plug 2 appliances in.
To charge the battery I would normally keep it fully charged at home with a battery charger (under $20) because the best way to kill a battery is to let it sit whilst flat and if I'm only camping every 3 months I know it will happen.
To charge the battery whilst driving I'd run a pair of cables from the battery thru a hole drilled thru the back of the cabin and then terminating in a plug which I can stick into the car cigarette lighter so the battery gets a top-up charge when driving. The cable can even be household 2 or 3 core wiring - it only needs to carry no more than 10 amps. At the battery end I'd use simple alligator clips onto the spare battery.

If I thought I would not need to charge the battery driving to my campsite as the battery is already fully charged from being on charge at home I wouldn't even bother with the complication of wiring it in - just have the double cigar lighter connection.

The above is just skimming over what is needed. I like the old K.I.S.S. principle.

But in the end it's your choice and you need to be happy with the design.
Here is a link to a good site:
Caravan & Camper Battery Charging @ ExplorOz

Thanks Hako.
Umm yeah, My original intention has changed drastically lol. Im going for a full fixed setup that I can install once and not have to worry about it.
The ute will be used for camping regularly, plus fishing and working in the back so the light there will be good. I can get the 660CCA Batterys cheap, will probably end up with a 510CCA sealed though, Ill just see what my mate has in stock at the time.
Im thinking by running the isolator etc I wont really have to worry about the battery not getting charged and getting ruined, though Ill still run a isolator switch in the cab to turn it off and on.
This quickly turned from a cheap job, to a once off expensive setup lol, but still it wont cost me more then $250. Cost me $100 for the isolator, isolator switch, and 4 marine plugs, then I've only got the wire, battery and battery box to go