I recommend ditching the solar panel all together and just using a dual battery setup. That’s what I did and I’m very happy with it. This setup is simpler when it comes to installation, uses less wiring and components that can fail and most important of all, gives you the ability to jump-start your main vehicle battery in the middle of nowhere.
I installed 2 good batteries in the engine compartment. I also installed an isolator / combiner that charges each battery separately when needed and keeps them isolated from each other. This way if I drain one of them the other stays fully charged. It also lets me jump-start the main battery from the auxiliary battery.
I hooked all my accessories (and fridge) to the Jeep’s regular main battery. Yes, the main battery. I hooked nothing to the auxiliary battery to save it for jump-starting if needed.
A good main battery can power the Jeep and all the accessories (including a 40L Engel) with no problem for more than a day on a full charge. Once I start my engine it gets charged again. If I’m camping in the same place and I’m not moving around with the Jeep, I run the engine every morning for 10 minutes or so to recharge the battery.
In the case the main battery looses it’s charge and I cannot start the Jeep, then I flick the isolator / combiner switch and start the vehicle from the fresh auxiliary battery then return the switch to isolate them again. I leave the engine for 10 minutes to recharge the main battery.
No solar panel, regulators, unnecessary wiring or any of that. Even if the isolator / combiner fails. Just disconnect it from the batteries and jump-start the car manually.
More info / tips:
Install your best/newer battery as the auxiliary battery. You want to make sure the juice is there when you need it the most. Even if your main battery is not in top condition and you have jump-start it every day. Other wise you won’t have backup.
There are ready-made battery trays that accommodate dual batteries for popular 4x4 brands. But I decided to make my own from angled iron I had lying around.
The isolator combiner I use comes from
Hellroaring . It’s also available from
Painless Wiring ,
Wrangler NW and
ARB .
Get deep cycle batteries not regular batteries.
Optima Batteries ,
ACDelco . Regular batteries tend to go bad if discharged completely often. The deep cycle variety can handle up to 500 total discharges. They’re very popular with marine people just for that reason.
500 total discharges is a big number. Even if you leave your Engle and lights on all night and you can’t start your vehicle in the morning that’s maybe 50% discharge at most. It’s just that cars needs full charge to be able to start.
Feel free to ask me if you need any help with this project.
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A.B.
www.ShortWheelbase.com
[This message has been edited by A.B. (edited 16 February 2002).]