DIY 400 Watt Solar Power System Beginner Tutorial


So we’re, going to build this up all the weight and attach some solar panels and a battery and talk about some safety considerations that we didn’t talk about in the last video. The first thing we’re going to do is make it nice and pretty with some heat-shrink you will need to do, is buy the proper size, heat shrink for the application and use a heat, gun measure and cut a piece of heat shrink and Use some scissors to cut it off, and this is what it should look like also notice where the heat shrink goes up to you.

You don’t want to go in too far so that it would obstruct the connector and you don’t, want it going too far back down this way, because you want to protect this joint. This is what they look like when they’re done and that didn’t take much time at all.

This is what it looks like when we put it back together with heat shrink. Now I want to talk about the fuses and circuit breaker sizes that I chose for the system, so in this system I use the 170 amp circuit breaker.

That works really well with this size inverter, but we also have it connected to a fuse box for most off-grid solar power systems that are mounted in RVs. Most people don’t use, mini amps from this, and most people, don’t, run the peer sine wave inverter to maximum load all the time.

So usually, I can get away with sizing the circuit breaker for the inverter. But if you plan to use a lot of power from this fuse box, this needs to have its own fuse or you can bypass this connect, this wire, this wire and this wire to a stud on the board and then put like a 300 amp fuse on This one and then that will be the main fuse on the battery.

But if you do this, you need to make sure that this wire can handle 300 amps. This is only a 2 gauge wire and it’s, pretty short, so it probably could. But you need to reference a wire gauge chart just to make sure wanted to have a circuit breaker on the board.

So beginners could see it there and if they miss the bolt on fuse, they would still be ok. But you don’t need to have this if you have a bolt on fuse that’s sized for the inverter and the fuse box, what you can do is keep this circuit breaker there and see if it trips, if it trips, You can swap it out for a larger one.

Let’s. Talk about grounding these two components: the inverter in the solar charge controller. Typically, they come with a little screw on the case and down here on the inverter. We have it right here and what these do is connect to earth ground technically, because we don’t have an earth ground in an RV or a van or a car.

What we need to do instead is ground it to the chassis. Typically, in most vehicle mounted systems, the negative terminal of the battery will be chassis mounted because it can be hard to find a chassis ground inside of an RV you, where everythings, wood and fiberglass.

What you can do instead is wearing a wire from the ground to a negative post or a negative bus bar so from here to here. So we’re gonna add a 12-gauge wire that goes from that to the negative and from there to the negative it’s.

What should look like? We are using a 12-gauge wire because that’s. What the inverter manual recommends of the proper size terminal connector and it goes to ground. It is preferable to do it to the chassis.

But if you can’t get it to chassis, do it to the negative bus bar ground or somewhere, and then we also have the one for the solar charge, controller, a blue wire, and I hate it underneath there and it also goes to ground.

So this system is now grounded. Please check your inverters instructions and see what it recommends for grounding. If you have this system stationary and you can have a true earth ground, you want to put this directly to that to found the solar panel.

So we can hook this up to the system. Solar panel doesn’t have mc4 connectors, so I just made some temporary ones for demonstration purposes. If you get a slower panel, it will say positive and negative, and these wires will connect to the solar charge controller at the positive and at the negative.

This is only a 75 watt solar panel and for this size system I recommend 400 watts of solar panels. So if you have 4 100 watt solar panels, what you’re going to have to use, is branch connectors and when I suggest, is putting one in two in serious and then connecting it to a branch connector and then putting the other two.

The last two in series and then connecting it to a branch connector. So that means that you & # 39. Ll only have two wires going through your roof and into the solar charge controller. For this example, we’re just going to test it with one panel to show you how to hook it up with the mc4 connectors and it’ll connect directly to the solar charge controller to make sure if it works guys.

Now we have the complete system a battery to hook it up to first, and then we can connect it to the solar panel. So here we have the positive cable and the negative cable. We need to connect it to the negative on the battery and then the positive on the battery, and you can see.

I have a bolt on fuse that’s rated for this system, so some people say it’s better to connect negative first and some people say it’s better to connect positive. First, I don’t. Really know anymore, so I just put whichever ones easiest, because this is a battery terminal.

You do not want to use any washers, except for lock nut washers, and you want the bottom of the used to be flush with the battery terminal and when you connect this for the first time it’s. Gon na spark.

Just like that. Did you see that that’s, because the capacitors in the inverter were charging up? Please check out my book if you wan na learn how to build large battery banks properly, but for this one this is a nice easy example for beginners, and this lug is actually too big for this thing, so I’m using a screw as A washer, but you don’t want to do that.

You want to use the proper size. This battery is so small and I’m, not going to use it for anything else. So I’m gonna make it work for now, when we have the positive and the negative connected to the battery first or connect it to the battery, we will see a green light come on on the solar charge controller.

Now let’s connect some things to the solar charge controller. We have a temperature sensor that plugs in right here and then we bring this over to the battery most of the time. These temperature sensors will actually connect to the negative terminal, because this does not have a little hole to connect it here.

What I like to do, is I high it right here or you can let it dangle close to the batteries, but you need it to be close to the battery somewhere. Now we can connect the MT 50, so we plug it in right here and then we have our little MT 50 string and we plug it into the back.

And after you connect it, you can see what’s going on with your system, and now all we have to do is plug in the solar panels and see how much power they produce. So battery is connected. Everything is old and everything is working.

Now we can connect the solar panels, so we have mc4 connectors and we’re gonna connect ground first and then the positive and now a green light just came on. That is a very good sign. That means the polarity current is correct and it’s now charging.

So we can look at the MT 50 screen and you can see 20 volts is coming in through the solar panel, but we need to wait for it to modulate the current and everything so it actually goes to the battery, and if the battery is full, it Will not charge, but right now we already have 3.

2 amps and it is charging this battery and that’s. Pretty great isn’t it I mean we just hooked it up and it’s charging a battery. So this system works, so I let it sit for about 30 minutes is charged up to fourteen point four volts, which is great also the settings on the solar charge.

Controller are set for sealed battery, and that means it charges to fourteen point five. That means that if you have an AGM battery or a lithium drop in lead acid replacement, you don’t have to change any of the settings on the solar charge controller.

If you buy all the recommended components on my website, they work together and you don’t have to program anything. Now we can load test the inverter to see if our system is actually functioning properly.

So when I turn this on, the cooling fans will probably start and it works, and now, while the load is running, you can see the voltage drop on the MT 50 and you can see that the amperage will go up because it’s.

Now charging the battery faster, because if the battery is full, it will not charge up. If you put a load on the battery, it will say: oh no, we need to compensate for that load and the solar charge controller will start taking out electricity from the solar panel, but yeah.

This is great. It actually works really well and when you first get a system, you want to run a large load and feel all the wires. You want to make sure that nothing is getting hot, feel everything with your hands, because this is a low voltage system.

You will not get shocked, but you want to make sure that if any of the connectors is getting hot, you need to redo that connector to make sure that you don’t, have any bottleneck situations here. So after running a continuous 1500 watt load, it started getting warm, but that’s.

Fine, it did not get hot at all, so we use the proper sized gauge wire and we actually over gauged it. This battery can discharge what we need. So this system actually works really well so awesome when you build these systems and it can actually power appliances, sunshine goes in charges the battery, and then we use the power with the inverter.

If you run a large load on this system in the circuit breaker trips, that means you need a larger one. For this system. I used a 1500 watt load on this inverter in nothing tripped and nothing heated up.

So I can leave these circuit breakers and fuses, as is if this fuse box needs more power, and things do start to heat up or the circuit breaker blows. I will need to change out the circuit breaker. We over engage these wires, though, so this is pretty future-proof and we can scale the system in the future if we need to sit guys.

I hope you found this video useful. It’s, great hooking, everything up, so you can see it all in action and yeah. I hope you guys learned something from this and let me know if you have any questions or comments below I’ll talk to you guys later bye,