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Author Topic: Will this setup work?  (Read 877 times)


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Will this setup work?
« on: August 22, 2017, 01:59:54 PM »
Hi, I have an old cabover camper I just got and it uses an 8 pin connection to run the fridge and water pump from the batteries up front. I am trying to boondock for long periods and have a limited budget so I am hoping this might work although I realize it won't be very efficient but it will hopefully only be a temporary setup as I want to get a bit nicer camper and this one is on it's last legs.

I want to connect a 100w renogy panel through their 30amp pwm controller to a 150ah agm battery and then run that to a 1000w pure sine inverter. Here's where it gets weird.. From that inverter I want to run a battery maintainer/charger (the 3amp charging type) to the front batteries. From reading about the 3amp charger maintainer I believe it bypasses the batteries when any load is trying to be pulled from them so if I understand correctly it would essentially be using the inverter power to run the small loads it would detect.

The pitfall/s I'm guessing are it might be confusing to the charge controller or maybe it would short out somewhere in this weird loop. I really won't be using much power and I am mostly just trying to run my propane fridge for a week or two without getting stranded by somehow bypassing the car batteries up front. I also considered wiring an 8 pin to a different marine battery I have  somehow but I'd have to research that a bit to see if that's possible or even a good idea.

I think the fridge is hard wired to the battery up front because if I plug the camper into shore power the gas ignition doesn't spark so plugging the camper into the inverter doesn't solve my issue. There is a plug from the fridge that I haven't tried plugging into the inverter because I think it's a 12v plug and I'd need some kind of adapter or something otherwise I might damage the fridge?

Any thoughts or advice are greatly appreciated. Thanks Alex


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Re: Will this setup work?
« Reply #1 on: August 22, 2017, 03:02:21 PM »
The 3a charger won't work the loads are too great. Why convert 12vdc to 110vac then back to 12vdc?

The plug on the refrigerator is 110v there is an option to run on 110v that is why the gas doesn't start when you plug in.

I think you are overthinking it you just need to hook the battery into the 12vdc system of the camper and use the solar to charge it. And isolate it from the truck system when it's not running.
The inverter could be used for small 110v devices if you need to.
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Re: Will this setup work?
« Reply #2 on: August 22, 2017, 03:21:53 PM »
Okay cool thanks, I'll try plugging the fridge into the inverter and that will probably solve my problem, I can probably do that with the water pump too if the plugs are 110 which I was worried they might not be.

One more question if you or anyone knows. I have one of those tiny 1.5w harbor freight solar panels that has no built in charge controller, is that safe to use to keep my batteries maintained up front if I'm away from the truck for a week or so or should I get a controller to be safe? I've read both are okay but I'd rather be safe than sorry,  it would be on two large interstate car batteries that are wired together and I don't want to overcharge them so I was thinking of picking up a controller for it, or  maybe I'd need two of those or just a bigger panel? Thanks again. Alex
« Last Edit: August 22, 2017, 04:12:30 PM by AlexCa »

John From Detroit

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Re: Will this setup work?
« Reply #3 on: August 22, 2017, 05:39:37 PM »
One of the nice things about 12 volt DC systems (All DC systems) is that you can parallel 2,3,4,12,100 different power sources and they won't compete.. Now it may happen that one will provide all the power, and the others sit there and relax.. (This is how that "Automatic battery switching" happens by the way.. The highest voltage source provides the power).

But I'm not clear on what you are planing. a 100 watt (10 amps peak) solar panel via a 30 amp Controller to charge the batteries and a 1,000 watt inverter.  Why the 3 amp battery maintainer?

Or is it the 100 watt panel charges HOUSE batteries which power the Inverter which powers the maintainer which charges the CHASSIS batteries. .that should work.. provided you have enough solar power.. I'm not sure you do .
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Re: Will this setup work?
« Reply #4 on: August 22, 2017, 06:04:31 PM »
Yeah you nailed what I am trying to do, the panel charges the house battery which didn't come built in with the camper so I'm trying to use an agm battery for now to power everything without using the front batteries, but the other poster pointed out I would probably need more power. I think I can bypass those batteries up front (thanks to the other posters advice) by just plugging what I'm going to use into the inverter and maybe put a little charger on those batteries up front for now or just start the truck every few days.

If I understand correctly by the time the appliances plug into the built in outlet behind the fridge the  DC has been converted to AC? I do really just need another panel, battery, isolator and some other things but the fuel pump on my truck went out and has cost me a fortune to get repaired  :-[ so I'm trying to build something very basic for now until I can save some more money to invest in it.

john owens

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Re: Will this setup work?
« Reply #5 on: August 22, 2017, 07:33:33 PM »
If you have a built in plug in behind your fridge that should be the ac shore power receptacle..any 110 appliances in that camper will only run on shorepower wheather it is in a campsite or hooked up to a generator. Anything else will run off of 12 volt power. There are tons of posts regarding soler power and what you may need for your application...look in archives or wherever the guys have them stashed on the site.
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Re: Will this setup work?
« Reply #6 on: August 22, 2017, 07:42:57 PM »
Great thanks, I think I'm on the right track now thanks for confirming that and thanks to everyone for all the helpful replies it makes more sense now. Alex