connecting solar panel to van

G'day johno59

Run the cable from the panel to the voltage regulator , wire the regulator as close to the battery as is practical. I presume you have two anderson plugs cos just one is no good to you.
I have used Narva 6mm twin core cable, this has 4.58mmsq cores for good transfer of the current with little voltage drop.
If the wire you have isn't relatively heavy it will act as a resistor and drop the voltage getting to all components and reduce the 100w which is more likely only 75-80 watts in reality, down to about 50 watts of output. So don't gauge all your calculations for power use on getting anywhere near 100w cos it won't happen.

If running a laptop, it is more efficient to use the 12v power you have by buying a 12v -19v dc/dc convertor from jaycar store. This costs around $60.

The use of an 12v to 240vac inverter is good for some things but is less efficient and you will end up using more of your 12v battery charge.
If buying an inverter for other use make sure it is a full sine wave unit because many items nowdays have switchmode powersupplies inside them and they don't like the modified Square wave. Some don't start running and some items burn out because of this crappy 240vac wave form.
Unfortunately they are advertised as Modified SIne Wave but in fact they are Modified Square Wave and more inefficient as well.
I tried my laptop on the non sine wave model and the power supply for the computer wouldn't start charging and just got hot, i didn't let it sit and burn out.

Ross M

Hi Johno,

100 watts is a good choice and a good starting point if you want to take it further, though may not be needed in your case.

Is the panel going to be fixed or movable.

As Ross said, mount the regulator as close as is practical to the batteries but keep it where it can be checked from time to time.

The regs have a clear instruction marked on their front panels as to wiring, which wire goes where, and you will only need the Anderson plug if the panel is portable.

If the panel is portable then put the plug in a convenient place for your needs, usually on the A frame and you can put the other plug on a long lead to the
panel.

All the regulators I have or have seen have the contacts across the bottom set up in pairs running left to right as follows. Pos + Neg for the panel then Pos + Neg for the battery supply, then Pos + Neg for the load.
Six connectors in all.

You do not need to run the load off the load contacts unless you want to.
All my load runs from the batteries only. The panel and regulator just supply batteries only. The load circuit usually has a program whereby it will shut down the load when the battery reaches a specific low voltage in most regs I have seen.

Hope this helps,
Cheers, Bruce