Battery Systems

Yarn ..... I have the 99 TD Jack with ONE main battery and an aux - has always started ok, but the Jack injection/oil story is a long one. Yours has the two batteries in tandem, because Isuzu stuffed up with the oil driven injection for cold climates and of course took the easy way out (what manufacturer doesn't ? - now you don't have room for an aux battery ! - but do they care ?).....two batteries in tandem means you can try and start it for much longer, in very cold climates. Its not a problem in mild climates. Significant accessories should not run from the main battery, because the Jack needs every amp when you are camping out and wake up to find ice on the tent ! Suggest if you are not likely to work in extremely cold climates you install a battery isolator system (Rotronics etc) in the line that connects your two pos terminals. When you shut down, the current second battery will be disconnected. With accessories wired to the second battery, you main won't get flat. When you start up, you will only have the main battery on line - the isolator will connect the second battery for charging, when the first battery is happy. Check out the isolators at a good 4WD shop - Rotronics are on the web too.
Thats how I see it."This is a situation, up with which, we should no longer put ! (W. Churchill, on plans to reduce 4WD access in some parks).

Howdy Mate - I am just a visitor to this site but have just decided to join up - it is awsome and full of really helpful info. re the Jackaroo - I have one, a 1999 turbo diesel, and like yours it has a twin battery setup. I recently went though all the pains of what I was going to do for auxillary power, and after talking to heaps of 4wd shops and auto electricians, here it is.

Anodised rust free heavy duty battery cradle ($120) replaces the one on the passenger side, accommodates the two starting batteries.
The starting battery on the drivers side gets transferred to the other side and sits right next to its brother. The re-wiring is pretty simple for an auto sparkie.
The battery just moved from the drivers side gets replaced with whatever you want - for auxillary purposes - I used to use a cheap 4wd battery ($85, N70ZZL or something like that) but it only lasted about 18 months (in my previous car). I recently bought an RAA one which they claim has a mixture of heavy duty/deep cell characteristics for $170 which should last longer - time will tell. The reason we did all this was because there is not enough room for a larger battery on the passenger side at all, and because the drivers side cradle is the one that they used to fit a bigger battery to before going twin, there is plenty of room for whatever size you want. I had the option of just having a smaller battery (say 520cca) as auxillary, but wanted more to keep the fridge running longer.
To isolate they used a redarc which if you want to know more about search for it on this forum and you will see how much of a rap they get. My sparkie wanted $210 for it, but apparently you can order them for about $110 (again the search will give you details).

All up it cost me about $700. Not cheap, but for me worth it. Still has the original specified cranking power plus the benefit of a larger Aux battery. Go to a 4wd place and they would probably want about that much if you were going to use your existing setup.

This may not suit your budget or needs but I just present it as an option to consider. GOOD LUCK.

p.s. If you haven't already caught on - I'm not a very techincal person, which is why a got a sparkie to do the lot.

p.s.s. Have you done much 4wding in your Jack and how has the clearance been with that big fat metal thing on the driver side underneath that hangs down - I think it is the tranfer case or something. Also if anyone else is reading this does lifting the car raise this big fat metal thing up or not?