Bad Advice

[BulldawgSolar]

Hi folks, I am a bit frustrated and humbled. I would like to set up an 0ff-grid system with the components I have collected over the last 2 years.

I assumed incorrectly that over that time I cold "figure it out" but I could NOT. Thru FIVR, I paid a Pakistani "electrical engineer" for some custom plans and it was a disaster.

I was hoping someone could take a look at my components and help me configure them to max out their capabilities. I'm fairly certain I have a situation overkill in some areas for my purposes:

I have a 25 ft travel trailer that is semi-permanently parked on some rural property of mine, I would also like to be able to partially deconstruct the system and attach it to my Sprinter van, potentially.


I currently have collected the following(all new, btw):


8- 12v/150Ah lithium batteries

1- Harbor Freight 12V 5000W/10000@ Peak, modified sine wave invertor

1- Victron Smart Solar Charger 150v/35Amp, 12/24/36/48

30 ft- 2 gauge/2 AWG wire with crimping tool and copper connectors

1- 150Amp,12v-24v in-line fuse

1- Eco-Worthy 4 String Combiner Box with fuses

10- 100W monochrystaline panels currently mounted 5x100W x 2

6- 50 ft 10AWG solar panel connection wires

5- 210W monochrystaline panels currently mounted 5x210W

10- Y branch connectors, 20A-DC1000V, 14-10 AWG

1- 12V/24V Master On/Off/1/2 switch

2- 4 stud 3/8" power distribution block


My travel trailer has a 15,000 BTU HVAC, I'm replacing the 12V internal lights with LED, regular RV fridge, oven(wont be used much), multiple strands of outdoor LED lights, and a 1.5 HP submersible pump.

The pump hasn't been purchased yet but will continuously pumping fresh water up from a lake and creating a waterfall feature.

I really need someone to advises me on the best way to arrange the batteries and the best way to connect the 3 banks of 5 panels. Is my Smart Controller too small for the purpose? I was originally advised to set my 8 batteries up in 2 banks of 4 resulting in 2 x 48V/150A which burned up my power inverter. After reading the manual it clearly reads that the 5,000W/10,000W inverter is ONLY for 12V.

Should I reconfigure my batteries into a single bank of 8 12V/1200A? or get a 48V to 12V converter to hook up between the battery OUTPUT and the inverter INPUT?

Any advice would be so appreciative.

 

[chrisski]

1) Recommend a new inverter. A 5000 watt 12 volt inverter is dangerous.

2) Get your power requirements. I have a 24 volt system that I MAY be able to power a 15K BTU AC, but I’m waiting for weather to warm up to power it on. Basically, you may have enough batteries, and maybe panels for one high wattage at a time for a good portion of waking hours. High wattage loads are an electric water heater,fridge, AC, and probably a couple others.

3) you have two different sets of panels with one SCC. I recommend a second SCC. One for the 100 watt panels, and one for the 210 watt panels.

 

[HRTKD]

1- Victron Smart Solar Charger 150v/35Amp, 12/24/36/48

10- 100W monochrystaline panels currently mounted 5x100W x 2
5- 210W monochrystaline panels currently mounted 5x210W

10- Y branch connectors, 20A-DC1000V, 14-10 AWG

I'll focus on this part. The Victron controller is excellent. However, we don't know if the panels and the panel configuration is too much for the controller. Please provide the full specifications for both sets of panels as well as confirming how you have them wired. It sounds like the 100 watt panels are wired 5s2p and the 210 watt panels are 5s.

That's a lot of branch connectors and I don't think you'll need all of them. But it depends on how we reconfigure your panel wiring.

As chrisski said above, you're going to want to buy another solar charge controller. Another Victron, but hold off on buying one until we know more about your panels and how they're wired.

 

[chrisski]

Now that I look at this, I see that the designer wanted one set of panels run in through the combiner. Probably the 100 watt panels. The Ecoworthy combiner comes with pre-installed circuit breakers, I think 10 amps, so that is good only for strings of the 100 watt panels. Ufortunatley you said its the 4 string panel, would either have to go with the 2S4P and have two extra panels or purchase two more for 3S2P. If you go 48 volts, the 2S would not work, nd the 3S would usually work, but 4S would be better.

Can you describe your branch connectors? Are they 2 branches or is there 3 or more? Because the 210 watt panels are likely more than a 10 amp circuit breaker should. Be hooked to, would not be good to put these through the combiner without switching the 10 amp circuit breaker. You’d need an even amount of solar panele to use the branch connector like 2S2P or 3S2P. THe same thing may apply to a 48 volt system. 3 Panels in series would usually work, but 4 panels in series would be better.

 

[Delmar]

1- Harbor Freight 12V 5000W/10000@ Peak, modified sine wave invertor

I also recommend getting rid of the Harbor Frieght inverter because its modified sine. Your sensitive electronics won't be happy.

 

[BulldawgSolar]

1) Recommend a new inverter. A 5000 watt 12 volt inverter is dangerous.

2) Get your power requirements. I have a 24 volt system that I MAY be able to power a 15K BTU AC, but I’m waiting for weather to warm up to power it on. Basically, you may have enough batteries, and maybe panels for one high wattage at a time for a good portion of waking hours. High wattage loads are an electric water heater,fridge, AC, and probably a couple others.

3) you have two different sets of panels with one SCC. I recommend a second SCC. One for the 100 watt panels, and one for the 210 watt panels.

I'm sorry for the slow response. I got sick.

What do you mean by dangerous?

I'll focus on this part. The Victron controller is excellent. However, we don't know if the panels and the panel configuration is too much for the controller. Please provide the full specifications for both sets of panels as well as confirming how you have them wired. It sounds like the 100 watt panels are wired 5s2p and the 210 watt panels are 5s.

That's a lot of branch connectors and I don't think you'll need all of them. But it depends on how we reconfigure your panel wiring.

As chrisski said above, you're going to want to buy another solar charge controller. Another Victron, but hold off on buying one until we know more about your panels and how they're wired.

The 100W panels are 12V (max 18.4V, max current of 5.44A) I currently have 2 rows of 5 100W panels hooked together in series plugged into the connector box, not hooked together. the other 5 panels are 210W 12V ( max voltage 17.0V, max current 11.76A) are hooked in series and directly into the 4 string connecting box. I haven't hooked the entire thing together with all of the batteries since I fried the 1st inverter.

As far as the power requirements, I anticipate having a 1.5-2 HP submersible pump (which I haven't bought yet) running pretty much full time filling up a cistern from a lake 32' below and when full running back down to the lake aerating the water as waterfall/water feature. But it can be switched off. The AC running at night in Georgia is the priority, the fridge can be ran by propane. The next priority is running 6-8 strings of LED lights. The microwave and oven will be used rarely.

 

[BulldawgSolar]

I also recommend getting rid of the Harbor Frieght inverter because its modified sine. Your sensitive electronics won't be happy.

Do you have a suggestion for which inverter I should get. The way the travel trailer is set up all of the power requirements can be met by plugging in 2 standard 120V extension cords to an outlet or 1 220V cord plugged into a generator or 220V outlet.

 

[BulldawgSolar]

I'm sorry for the slow response. I got sick.

What do you mean by dangerous?

The 100W panels are 12V (max 18.4V, max current of 5.44A) I currently have 2 rows of 5 100W panels hooked together in series plugged into the connector box, not hooked together. the other 5 panels are 210W 12V ( max voltage 17.0V, max current 11.76A) are hooked in series and directly into the 4 string connecting box. I haven't hooked the entire thing together with all of the batteries since I fried the 1st inverter.

As far as the power requirements, I anticipate having a 1.5-2 HP submersible pump (which I haven't bought yet) running pretty much full time filling up a cistern from a lake 32' below and when full running back down to the lake aerating the water as waterfall/water feature. But it can be switched off. The AC running at night in Georgia is the priority, the fridge can be ran by propane. The next priority is running 6-8 strings of LED lights. The microwave and oven will be used rarely.

On the branch connector, I bought them but I don't see a use for them yet.

 

[BulldawgSolar]

Now that I look at this, I see that the designer wanted one set of panels run in through the combiner. Probably the 100 watt panels. The Ecoworthy combiner comes with pre-installed circuit breakers, I think 10 amps, so that is good only for strings of the 100 watt panels. Ufortunatley you said its the 4 string panel, would either have to go with the 2S4P and have two extra panels or purchase two more for 3S2P. If you go 48 volts, the 2S would not work, nd the 3S would usually work, but 4S would be better.

Can you describe your branch connectors? Are they 2 branches or is there 3 or more? Because the 210 watt panels are likely more than a 10 amp circuit breaker should. Be hooked to, would not be good to put these through the combiner without switching the 10 amp circuit breaker. You’d need an even amount of solar panele to use the branch connector like 2S2P or 3S2P. THe same thing may apply to a 48 volt system. 3 Panels in series would usually work, but 4 panels in series would be better.

Did I make a mistake of not buying ALL 110W or ALL 210W panels instead of mixing?

 

[BulldawgSolar]

It appears I need to widely upgrade my components or dial back my expectations. The off-grid calculator says I need a 6 KW system. 3,850 Total Watt peak load, 13,000 total watt hours per day. Dang

 

[chrisski]

Did I make a mistake of not buying ALL 110W or ALL 210W panels instead of mixing?

Not a mistake at all. Just need to set up differently. I have three different sets of panels and three SCCs I use for my build.

What do you mean by dangerous?

I have a 2000 Watt 12 volt Inverter. It’s a pretty good inverter. It is the SAMLEX PST 12-2000. I used 4/0 wire an a 200 amp ANL fuse. That wire is aas thick as a finger. Difficult to work with. With a 5000 watt inverter, you’d need wire even thicker and perhaps 500 amp fuses. Going to a 500 amp fuse is a hole other level and the tools for the thick wire become even more expensive. Little mistakes coils mean fires.

I see reviews on Amazon of people claiming inverters were bad, but they had used wiring way to small and were complaining of the inverter cutting off and the wire getting so hot it would burn to the touch. That means they used wire too thin.

If you can set it up correctly, than a 5000 watt inverter could be fine. I can’t set it up for 5000 watts at 12 volts.

 

[BulldawgSolar]

I'm thinking about ordering this:

Sigineer Power 48V 3000W Off-Grid Solar Inverter Charger,48V DC to AC 120V Pure Sine Wave Inverter,Built-in 80A MPPT Solar Charge Controller,Parallel Operation,for Home,RV https://smile.amazon.com/dp/B0936C689V/ref=cm_sw_r_apan_glt_i_22N8ENZS4W8SPPVR713Q

It appears this would solve my problems:
- remain a 48V system
- provide a 2nd MPPT SCC for my bank of 5 200W panels
- 48V 120A 3000W pure Sine Wave inverter as opposed to my 12V 5000W hybrid Sine Wave

Any thoughts?

 

[Rednecktek]

You're still going to want at least 1 more panel so you can set up a 3s setup, but that'd be the only issue I can see with the plan. Prime numbers are a pain to divide by.

 

[BulldawgSolar]

So:
1- 5 X 100W
1- 5 X 100W
1- 3 X 200W
1- 3 X 200W

????

 

[Rocketman]

As I read your posts, I was confused at the system voltage you are using/planning.

Are you going to use 48v or 24v or 12v. The lithium batteries you got - can they be hooked up in both serial and parallel arraignments? (Some cannot be hooked up in serial). Also, what is the max Ah the bms’s in the batteries can deliver?

On a project like this I like to rule out avenues that you cannot do.

You talked about using it on both a travel trailer and a van? That may be a bit problematic. Also eight batteries in a smaller travel trailer? Were you planning on mounting all this stuff in the trailer? Or maybe in a “power shed” next to the trailer? How often do you move the trailer?

Hopefully your batteries can be hooked up in series. Then you need to decide on 24v or 48v - with either of these you will need to replace the inverter.

Also will you need 12v off the system to run the 12v stuff on the trailer? If so what are the amps needed for that stuff - is it only lights and water pump or do you have slides and leveling jacks that need ran?

 

[BulldawgSolar]

The van thing is off the table for now. My thought was to just take 3 panels and 2/4 batteries.... scratch that.

My batteries are 3 of these:

SOKERDY 12.8V 150Ah LiFePO4 Deep Cycle Battery,1920WH,150A BMS,4000+ Cycles Lithium Iron Phosphate Rechargeable Battery​

My understanding was a 48V system was more efficient for charging and sustaining the batteries.

The trailer has a big deep cycle marine battery that I was going to just have a trickle charge,

BUT

the trailer can be ran by just plugging into a 220V outlet or standard 120V

and 5 if these:

ECO-WORTHY 12V 150AH Lithium Battery, Rechargeable LiFePO4 Lithium Ion Phosphate Deep Cycle Battery with BMS,​

 

[Rocketman]

I tried looking those batteries up and failed… do both of them say they can be hooked up in both serial and parallel arrangements?

 

[BulldawgSolar]

I believe they can be, but now I'm nervous and going to call the companies.

 

[sunshine]

I anticipate having a 1.5-2 HP submersible pump (which I haven't bought yet) running pretty much full time filling up a cistern from a lake 32' below and when full running back down to the lake aerating the water as waterfall/water feature. But it can be switched off. The AC running at night in Georgia is the priority

Time for a reality check!

The off-grid calculator says I need a 6 KW system. 3,850 Total Watt peak load, 13,000 total watt hours per day. Dang

Or replace the A/C with a fan and the pump with a 200w unit that only runs off surplus.

 

[BulldawgSolar]

You're still going to want at least 1 more panel so you can set up a 3s setup, but that'd be the only issue I can see with the plan. Prime numbers are a pain to divide by.

So buy 1 more 200W panel to 2 3 panel series of 200W?
1- 5 X 100W
1- 5 X 100W
1- 3 X 200W
1- 3 X 200W

????