Wednesday, Nov 25, 2015 at 09:09
Pretty much yes. The labels on the gear will give you the info you need. The fridge label may tell you it draws say something like 4 amps or 48 watts but thats only when the compressor kicks in so is worst case.
Once you know your max power consumption, you need to allow extra capacity for future gear, panel inefficiency plus weather. Clouds etc will drop the generating ability of the panel significantly.
Its all about what you can afford but I allow 50%-100% extra in the panel. If your wattage comes out at say 100 watts then try for a 200 watt panel. 200 is a very common size and due to the demand, pricing is pretty good.
You then need to get that power into the battery.
Most decent panels have a built in MMPT controller. You cab google these but essentially its a smart controller and optimises the panel output so as to provide the best charge to the battery. Its a 'must have' so make sure one is one the panel otherwise you will have to buy one.
The whole 12v battery / solar thing is going to screw with your brain a bit as you learn all this stuff :)
Not all batteries are created equal. Just because you have a 100A deep cycle does not mean you will pull that current for long. Some batteries (Optima Yellow Top for example) will let you flatten the battery a whole lot more before losing output. Depending on how you want to use the vehicle determines the quality level of the battery. ie spending 3 weeks in the middle of the Simpson dictates an Optima whereas a weekend away will likely only need a cheap Chinese thing.
Ok, so far you built yourself a solar charging system for your camper battery.
Now to complicate things even further, what about charging when you are driving. Have you thought about getting your trucks alternator to charge the camper battery?
Everything mentioned above still applies and your camper should remain a 'stand alone' system but you can add other gear to connect this to the truck power as funds permit.
This will start off a bleep contest with makes & models but you'll need to do your own research to cut away owner emotion from reality.
What I have is a big fat (6BA at least, bigger the better) cable running from the truck battery (the Aux one if you have two) to the tow bar where you terminate it into an Anderson (see Ebay) connector. The camper plugs into this and that cable runs back to your battery(s).
There will be a voltage drop down all that cable which will prevent the alternator ever charging the camper battery correctly (the bigger the cable the less drop). You need a DC-DC converter / smart charger to boost that voltage and charge the battery correctly.
Also, depending on your hardware choice, the DC-DC charger should be able to take the output of the solar panel and automatically switch between them as conditions permit. For this I use a Ctek D250s-Dual. Its an awesome piece of kit but you will be bombarded with opinions on other gear as
well. If you use the Ctek, it has its own MMPT controller built in so if your solar panel has one, you'll have to bypass it (dead easy).
So now you have a system that can charge the camper whilst you drive and a stand alone camper that charges via solar.
Hope that helps a bit :)
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