I've worked on this and done this a few years ago. its lucky you asked this here because you may have gotten into trouble without my information.
First, You need to make sure that you have a very good charge controller. Make Sky Blue is a very good one. If you get bad cheap ones they can mess up and damage your other parts and systems. I had first tried out cheap charge controllers, and they weren't strong enough and damage occurred. I fixed that but learned from this. There's a midnight something that is also a good charge controller, forgot the exact name of it. The make skyblue is cheap but versatile and durable. But no charge controller is perfect. And anything can get damaged. Check for damage also before you leave your system to sit alone without supervision, make sure everything works the way it should too.
Also, for the power inverter you need to make VERY sure its 'pure sine' and not modified sine. Modified sine inverters can't handle bigger power loads, which is kind of the point of having a power inverter. Now when you look at power inverters you will find some that are labeled as pure sine when they aren't really pure sine. You have to look in multiple areas and especially foreign companies lie. But there's this useful area in Amazon where you can ask a question to other people who have bought the same device. So you can check the details there and ask hey is this pure sine or modified sine and please confirm this. BUT DON"T Trust the selling labels for if its modified sine or pure sine. If its modified sine what will happen is that it will trip your system and turn off whenever you go to try to do something that uses a lot of power like cooking or heating. I was very surprised how many modified sine inverters can't even handle very low wattage, its shameful because it makes a modified sine inverter almost useless.
ALso if you get wiring that's not rated for the amperage of how much power your system produces what will happen is the wire can get really hot and start melting the plastic insulation. And then you have a fire hazard.
Many people use lithium batteries for their power setup of an off grid solar system. I will tell you I don't trust lithium batteries. They have a LOT of fire risk more than people say. They also CAN"T WORK, WON"T FUNCTION when it gets really cold. And that's a big issue because 1 of the main intended uses people have for their off grid solar is well what if I need to heat my cabin. Well you can't do that with lithium batteries, they stop working when it gets cold. When you factor both that and the fire risk together it makes lithium batteries unreliable.
If you look around for do it yourselfer videos that aren't selling and into all new stuff you'll find that many of them build good systems using lead acid batteries. Often go cart batteries. This means, you have a good chance to make it work using those. But you want to not go below 50% of stored power with lead acid. ALSO, you can't mix and connect lead acid and lithium batteries together... that's bad.
If you have other questions feel free to post them. I was also looking into
off grid solar Hilo setups, and there are some really great YouTube channels with videos to help people with solar questions. You'll need to educate yourself well because not knowing with solar can be a fire risk itself.
One channel that's good is G Bear's off grid ways. There's another one that's good too but I forgot the name of it. If I can remember I'll post it.
Now you may be thinking well I don't need a good system. I only want to do... X. So I'll get the cheap stuff. I would suggest you try to find stuff that's still cheap but still is like the specs I put above. You will probably use your system for more than 1 idea. MANY METRO systems are destabilizing right now. Utilities in some areas are destabilizing. This means its very possible even if you only intended your system to help with some chores or tools or whatever, that you might need it for other things also. So you want to build your system to be versatile and good enough that you can use it to help you in other areas.
