As a starting point you should determine the watts of the items you are going to run off your solar system. Once you know that then you need to get
the battery cables big enough to handle that load (with a buffer). You will then also need an inline fuse and a breaker to protect the cables, I usually set
the fuse at 125% of cable max and I set my breaker at the cable max.
Here is a simple cable chart that I rely on,
remember watts/volts = amps.
For me the key is to have a scalable system with enough battery power to run all I need all night and then be able to
recharge the battery(s) to 100% the next day.
12 volts to start but all components can be added to a 24 or 48 volt system later if desired - all flexible so
no money is wasted. 12 volts is the most inexpensive way to add batteries or panels - all others are close to double the costs when growth is desired.
I also like 12 volts because it’s safe and it doesn’t require multiple solar panels to start out (the panels must send in higher volts than the battery voltage
so higher voltages usually mean multiple panels in series). 12 volts is de facto standard on most yachts today and it meets the wattage requirements I have
with no problem.
Panels
Two smaller (easier to move & carry) 100 watt panels will give 200 w and cost right around half of a 240w panel.
You could start out with just one panel but it’s hard to recharge batteries to 100% running even a 12v fridge over multiple days of no sun with those watts so
I’m suggesting two as start.
This will allow you to add another one or two or as many as you need once you determine how much power you require.
When you add panels they need to be the same volts and amps (or very close) so this way you can add in 100 watt increments (cheap and light). The
controller I use lets me connect up to three of the 100w panels to it (max 290w at 12v).
Victron 100/20 will take up to 290 watts of solar. Can be used in 12, 24 or 48 volt systems. Offers the ability to monitor via Bluetooth - easy to
test if panel is getting most sun while you look at blue tooth results. Can be connected to cerbo later if you want to monitor via internet.
100ah … allows for up to 4 in parallel/series. You start with one and then you can see what you need. I had a 200ah battery and needed a little
more power. The manufacturer told me if I added a 100ah battery to this one it could void the warranty on both batteries due to how they would interact.
I didn’t need another 200ah I only needed the 100ah so I recommend starting with this so you can add what you need instead of being compelled to add
more at higher cost when you don’t even really need it. Stay flexible is my motto, here is a video I did on this subject
https://www.youtube.com/watch?v=6Jb-zEG4WEQ&t=5s
USB outlet with cigarette adapter to allow for charging phones and running a fridge if you so desire. This will also give you a volt meter so you can see how much voltage is in the battery.
Cables from the panel to the controller and from the controller to the battery
Inverter
The above will get you into solar power and let you run a 12 volt fridge, charge your tablet and phones, and run an
internet hotspot on USB. When you want to start
running appliances or any other 110 device I recommend this very efficient inverter and if you only have one battery I would add another one at this point.
