We lived off grid on a narrow boat for 5 years, so the accumulated wisdom from that is:
Use proper deep cycle batteries. You can't go wrong with Trojan brand, and if you can get 6v cells (batteries) and wire them in series (then parallel blocks of 2 batteries is series, if you want more than 2), so much the better.
If you can see yourself checking and maintaining the electrolyte level (topping up with de-ionised water, and preferably checking with a hygrometer) then "wet cells" will be cheapest. If you want "fit and forget" then AGM (absorbed glass matt) or gell cells will last longer (ie wet cells will die fast if you don't top them up when they need it).
Put as many panels as you can on, and wire them in series - probably (there are complications around if you expect one panel to be in persistent shade causing resistance and stopping the other panel working, but in most cases series gives you higher voltage and that means lower relarive volt drop over the cables). Mount them securely - the best way is probably the amazing 3M tape called VHB with a safety line.
Always fit a safety line (cable) to all of your panels.
Use a MPPT (maximum power point tracking) controller. This is as opposed to a PWM (pulse width modulation) controller which regulates voltage by cutting in and out rather than converting it - MPPT concerts and you don't loose power.
Use a good controller - I got a cheap one of eBay and it was fine, but you're probably better off with a branded one. Victron is good but so expensive. Tracer is a cheaper brand. I've always heard good things about Bimble Solar
https://www.bimblesolar.com/" onclick="window.open(this.href);return false; and they would be worth talking to.
Get a good battery monitor which uses a shunt - NASA Marine BM1 you can't go wrong with and as well as the reasonably accurate state-of-charge meter, you'll find you get to know your system much better and quicker just by seeing the voltage and amps in/out.
Use a marine quality fuse board - Blue Sea Systems is one you can't go wrong with.
My brother just gave me what I think is the best book on this subject by the wonderfully named William Errol Prowse IV - Mobile Solar Power Made Easy!
His website is pretty good too
https://www.mobile-solarpower.com/" onclick="window.open(this.href);return false;
And I would say a copy of that book is the best investment you can make in your new system.
I hope that helps and don't hesitate to ask more and good luck with the system!
Patrick
Sent from my ONEPLUS A3003 using Tapatalk
E D I T: for handling charge control from the alternator, I've had very good experiences with the things made by Sterling Electronics.
