Solar Setup Travel Trailer

[Svince1884]

Been doing my research........but alas there's no exact match to the system setup I wany to create to be found. So, let me pick your brains so I can get the warm feeling in my gut to proceed. Here goes....

2016 Keystone Bullet247BHS
4-Trojan T-105 Batteries
2-100 watt Solar Panels
400 Watt Wind Turbine
2- 30Amp Charge Contoller
12V-1000W/2000W peak Pure Sine Inverter
12V-2000W/4000W peak Pure Sine Inverter

My goal is to not have to use the generator or plug in while still being able to use all electronics and a 900Watt mini split AC unit.

My thoughts are to wire the four batteries in series/parallel for 12V @ 450 amps. Then one solar panel and the wind generator will be wired with one controller while the other will wired to the other panel. Both controllers then wired to battery bank. The bank is also wired so that I can get a charge when driving on the road or when plugged in as well.

Next I have both inverters coming off the bank. The 1000w/2000w will have just the AC unit plugged into it. The 2000w/4000w will have the 30amp RV line plugged into it to power everything else. The refrigerator, coffee pot, water pump, etc. Both inverters will have separate fuses.

So my question is, aim I day dreaming or am I onto something?

My confusion is with wire gauges and the inverters/ charging. For wire gauges, what sizes should I really be using. Are the stock wires that came with each inverter good enough? I mean if they can't handle the load why send them? And with the inverters, do I have to worry about current control while using them when the panels/wind turbine are plugged in and charging? I mean I'd like to be using the AC at the same time my batteries are charging. Also, is there any reason I couldn't keep the battery bank and charge controller in the same box?

[sensij]

Whoa, your math is way off. Please don't buy any of this, it is a pipe dream. More tomorrow, if someone else doesn't explain it first.

[Svince1884]

Well you don't know unless you ask. Oh boy.....lay it on me, I've got thick skin. But for kicks let's assume I bought "some" of this stuff lol.....and to save some sort of dignity let me explain more.

1. Nothing in my trailer is more than 1000w rating. If it is they won't be used at the same time. E.g. coffee pot on while the fridge is going too.

2. I did plan to run the AC unit and also the coffee pot at the same time. That's kinda what lead me to thinking about using two different inverters. I just didn't know if the batteries could handle the draw from both.

3. Inverters were given to me lol

[Logan005]

why not wire the batteries as 24 volts and get a nice 24 volt inverter and a 24 to 12 volt step down for your 12 volt loads? a 12 volt 4000 watt peak inverter is dangerous. the amps required at 12 volts to get 4000 watts is scary and would require huge wires that will get hot and could even melt and burst into flames. even in a RV that is designed for 12 volts, They are expected to be used occasionally with very lite loads. If you plan to "off grid" 12 volts and parallel batteries are not the way to go. Two charge controllers is also not wise, better to get the CC that is right for your system. If you have not purchased anything, Don't. Take your time and read up so you know what your doing and save yourself $$$ by buying the proper gear for your particular application.,

[Mike90250]

Your loads are WAY larger than your charging capacity.
First, forget the wind generator, they are next to useless unless you have to tie your hat on every time you go outside.
The panels are sized just large enough to barely keep the batteries trickle charged.
Forget heating appliances run from electric, There are much more efficient ways to heat. (propane, white gas.....)
Any regular load over 1,000w, needs a 24V system, the current density gets too high in the wiring components to be safe, and wire losses increase prohibitively.

Add up your loads in Watts x Hours
Add up your generation in Watts x Hours Your nameplate harvest needs to be 2x the loads (all in WH, forget amps or volts, simpler to use watt hours)

[Logan005]

you are not going to run an AC unit from a 12 volt or even a 24 volt inverter. coffee should be made on your propane stove, not an electronic drip machine. lite use of microwave is ok, but you will learn quickly how little power you actually have.

[Svince1884]

Thanks for the replies. I guess I was thinking 12v because I was given the inverters. I also liked the idea of being able to have my Tahoe charge the bank while driving. I'll be moving quite a ways every two days. I also didn't want to change out any of my 12V appliances to 24V.

I haven't bought much, was just contemplating how to use what I have ono hand. Which is all the same I listed except the battery bank; I've got two Trojans, and two 12V@85amp Interstate batteries. That being said, and with your input what about this.

What if I have two banks. One 24V and one 12V; the Interstate wired to 24V and the Trojan to 12V. The Trojan could use the 1000/2000W to power only the AC which again is only rated to 900W. -Logan- I installed a mini split system. It's not the same AC unit you see on travel trailers from the dealer. That bank could also be charged by tow vehicle and the generator when I plug it in.

Then the 24V can power the RV given all other major draw appliances run off propane. Obviously I'd get a 24V inverter. I'd wire the 12V panels to 24V and run those along with the turbine to charge that bank. Sadly I did already by the panels, turbine and hybrid controller. The run for the battery bank to inverter is less than 1ft.

Thoughts?

[sensij]

The Trojan t-105 has 207 Ah at the 20 hour discharge rate. Two in series have 12 * 207 = 2484 Wh. Discharge 50% max equals 1242 Wh, although for better battery life you might want to design to half that. So, your 900 W air conditioner might run 1 hr, but really, it will be much less due to the high discharge rate (depending on how often the compressor is running). Just a bad idea.

[Svince1884]

The 207amp is the 10-hour rate; 220amp is the 20-hour rate. Nonetheless I see your point. I'm just baffled people run an entire house off Solar then. Guess I understand why there's a gazillion panels on one ruff. I just figured they were trying to steal the sun. Jk....

Any input on the panels wired to 24V? There's so many mixed reviews as we all know.

As dumb as it may be not knowing, how do you know what percentage your batteries are at? E.g. 80%, 50%, etc...

[Logan005]

Thanks for the replies. I guess I was thinking 12v because I was given the inverters. I also liked the idea of being able to have my Tahoe charge the bank while driving. I'll be moving quite a ways every two days. I also didn't want to change out any of my 12V appliances to 24V.

I haven't bought much, was just contemplating how to use what I have ono hand. Which is all the same I listed except the battery bank; I've got two Trojans, and two 12V@85amp Interstate batteries. That being said, and with your input what about this.

What if I have two banks. One 24V and one 12V; the Interstate wired to 24V and the Trojan to 12V. The Trojan could use the 1000/2000W to power only the AC which again is only rated to 900W. -Logan- I installed a mini split system. It's not the same AC unit you see on travel trailers from the dealer. That bank could also be charged by tow vehicle and the generator when I plug it in.

Then the 24V can power the RV given all other major draw appliances run off propane. Obviously I'd get a 24V inverter. I'd wire the 12V panels to 24V and run those along with the turbine to charge that bank. Sadly I did already by the panels, turbine and hybrid controller. The run for the battery bank to inverter is less than 1ft.

Thoughts?

Ok, now that tidbit of information changes a few things, if you already only have two T-105's stay with 12 volts and your 12 volt inverters. For Now! If you only have two 12 volt panels, even in series you will never charge a 24volt bank. You may even damage it. Do not buy any more T-105's, the two you have are fine, just learn to live with the limited amount of power you have and make sure not to take the inverter over 700 watts, and momentary peak of 1000 or so. You can not add two T-105's to the batteries you have, you need to buy all brand new batteries for a bank. Mixing old and new is always a bad idea.

[Amy@altE]

The mini split is 900W, running it for one hour is 900 watt hours (Watts x hours = watt hours (Wh)). Each 100 watt solar panel can generate maybe 350 watt hours a day in the summer. As you said earlier, the T-105 @C-10 is 207 Amp hour x 6 volt, so 1242 watt hours each (Volts x Amp hours = watt hours). You don't want to use more than 1/2 the capacity, 1/4 is much better, so 310 watt hours each battery. So with 300W of solar and 4 batteries, you could run the AC for 1 hour. Not really worth it. As others have said, anything that makes heat or cold is tough to run off grid.

[Svince1884]

So the math is adding up. We'll, no AC unless on the generator. Thanks for all the clarification folks. So I wonder...

Can I keep both battery banks and install a switch that changes which battery bank I'm pulling from? Basically when the Trojans start to go beyond 80% I flip to start pulling from the interstate batteries.

My other question is why won't the two panels wired in in series charge the 24V system? If I up to 4 panels would it? Also, upping to 4 panels and wiring in parallel then to one charge controller. Is that the better setup?

Thanks again guys.

[Amy@altE]

I just saw that you already bought the turbine. What voltage is it, 12V or 24V? That's going to limit you for your battery bank voltage.

[Logan005]

My rule for 12 volt batteries is 12.1 volts, low voltage disconnect is set to 12.0, depending on the battery this is at or around 50%

[Logan005]

So the math is adding up. We'll, no AC unless on the generator. Thanks for all the clarification folks. So I wonder...

Can I keep both battery banks and install a switch that changes which battery bank I'm pulling from? Basically when the Trojans start to go beyond 80% I flip to start pulling from the interstate batteries.

My other question is why won't the two panels wired in in series charge the 24V system? If I up to 4 panels would it? Also, upping to 4 panels and wiring in parallel then to one charge controller. Is that the better setup?

Thanks again guys.

To charge a 24 volt battery you need in excess of 32 volts into your CC, anything less will not charge your batteries and will eventually damage them.