Solar Install Preparation

[NYRV'R]

Sorry if this is a repost but something happened with the internet gremlins and it did not appear my first post was submitted successfully.

I have some basic questions for the Solar Wizards of the group.

I plan on install 4 (four) 200 watt solar panels on the roof, connecting them to a Victron MPPT 100/20 in the basement storage area utilizing the Jayco solar prep wires (8 awg). I will place disconnect and fusing between the panels and the MPPT and again between the MPPT and the batteries. Lastly, I would place a shunt and monitor off the neg side of the batteries to monitor usage.

Is it that simple? What am I missing?

Will the onboard standard Jayco converter/charger work with Lithium batteries for now? I plan on having 4-6 lithium batteries in the upfront storage area.

Next year after my wallet has a rest, I want to install a Victron Multiplus 3000 converter charger and Smart Phase Selector Switch.

Yes I have a res fridge hence the need for 800 wats of solar and probably 6 lithium batts.

Thanks in advance for your replys and recommendations.

[klassic]

Your Victron sounds little on the light side at 20a for 800 watts.
You need at least a 50a.
My Mornigstar MPPT 30 hits 30a at peak sun with 530watts of solar. Morningstar told me that unless I followed the sun, then maxing at 30 during the hour that I have full sun would be efficient enough. With 530 watts I wouldn’t be hitting 30a after that anyways.
Unless your going series with your panels, then I think the 8ga wire might be too small for parallel. I’m not positive, but that’s close.

I connected one 260watt panel that was near the pre installed roof connector, and the other 260watt panel was farther away, so I dropped new 10ga cable pair down the stink vent pipe...drilled a hole where the pipe is behind the wall and pulled the wire out there...sealed up the hole with caulking...connected it to the 8ga jayco pre wire that came from the roof connector.

Then I have breakers positioned like you’re thinking, instead of fuses. I use the breakers to shut it down instead of switches.

I have a residential fridge and 435 ah of batteries..I can go with out power for a week with fairly consistent sun. And that’s with a kid pretty much all day playing an Xbox. You should do great with your lithium setup.

[Scottenj]

Originally Posted by NYRV'R

Sorry if this is a repost but something happened with the internet gremlins and it did not appear my first post was submitted successfully.

I have some basic questions for the Solar Wizards of the group.

I plan on install 4 (four) 200 watt solar panels on the roof, connecting them to a Victron MPPT 100/20 in the basement storage area utilizing the Jayco solar prep wires (8 awg). I will place disconnect and fusing between the panels and the MPPT and again between the MPPT and the batteries. Lastly, I would place a shunt and monitor off the neg side of the batteries to monitor usage.

Is it that simple? What am I missing?

Will the onboard standard Jayco converter/charger work with Lithium batteries for now? I plan on having 4-6 lithium batteries in the upfront storage area.

Next year after my wallet has a rest, I want to install a Victron Multiplus 3000 converter charger and Smart Phase Selector Switch.

Yes I have a res fridge hence the need for 800 wats of solar and probably 6 lithium batts.

Thanks in advance for your replys and recommendations.

I have 800 watts of solar and three lithium batteries.

You have to be careful how you wire the panels not to overload the Jayco wiring and the 100/20 controller is way too small!

I have written up what I did and bunch of other modifications here: https://www.scottenjones.com/JaycoEa...QSUpgrades.pdf

[billcf7]

If you connect panels in series/parallel configuration you will be putting approx. 22 amps to controller. Here is a good site to use for reference
https://ressupply.com/learning-cente...rt-and-formula

[mini4mw]

I'd do some more research and power calculations for 800W for safety. 100-200W is generally straight forward and little calculations need to be done. Over that you could burn things up quickly, faster as you increase wattage. Based on what you are planning, I'd start with the below and put the numbers together to verify power doesn't exceed max anywhere.

60 amp MPPT
mixed series/parallel wiring for solar panels
- best for partial shade
- increases voltage and decreases amps (better for 8 awg and power loss over length of wire)

If you put 800W straight through the 8awg ( I believe is default wire gauge for solar prep) it will most likely melt from 800W at 12V from amps, which could also melt wires nearby and cause a short (or just burn some plastic) and then bad stuff happens.

Number of good links already here. Below are a few more:
https://www.riversidetrailer.com/how...ge-controller/
https://zhcsolar.com/mppt-charge-controller-size-tool/

[Scottenj]

Originally Posted by billcf7

If you connect panels in series/parallel configuration you will be putting approx. 22 amps to controller. Here is a good site to use for reference
https://ressupply.com/learning-cente...rt-and-formula

That's not how you size the controller plus instead of using an on-line calculator you should get the specs for the actual panel.

Here is my install calculations:

I have 4 - 200 watt panels on my camper.

Max power for my panels is 21.05 volts and 9.5 amps.

I created 2 - pairs of panels in series, series adds the voltages and keeps the current the same so each pair is 42.1 volts and 9.5 amps.

I then tied the two pairs together in parallel, parallel adds currents and keeps voltage the same resulting in 42.1 volts and 19 amps. The Jayco 8 gauge wire is rated for 30 amps and at 19 amps, I am well inside the rating.

Now the controller takes the 19 amps at 42.1 volts and converts it to 14.4 volts and up to 55.5 amps, therefore I needed a 60 amp converter. If the original poster put in a 20 amp controller he would at most get 288 watts into the batteries.

[Scottenj]

Originally Posted by mini4mw

I'd do some more research and power calculations for 800W for safety. 100-200W is generally straight forward and little calculations need to be done. Over that you could burn things up quickly, faster as you increase wattage. Based on what you are planning, I'd start with the below and put the numbers together to verify power doesn't exceed max anywhere.

60 amp MPPT
mixed series/parallel wiring for solar panels
- best for partial shade
- increases voltage and decreases amps (better for 8 awg and power loss over length of wire)

If you put 800W straight through the 8awg ( I believe is default wire gauge for solar prep) it will most likely melt from 800W at 12V from amps, which could also melt wires nearby and cause a short (or just burn some plastic) and then bad stuff happens.

Number of good links already here. Below are a few more:
https://www.riversidetrailer.com/how...ge-controller/
https://zhcsolar.com/mppt-charge-controller-size-tool/

The Jayco wire is rated for 30 amps.

See my post above but take 4 - 200 watt panels, with the ones I have 2 sets in series then tied in parallel gives 42.1 volts and 19 amps. The 19 amps being well inside the Jayco rating.

The controller takes the 19 amps at 42.1 volts and converts it to 14.4 volts at up to 55.5 amps to charge the batteries so a controller needs to handle at least 50 volts and 60 amps, the Victron I have is 150 volts and 60 amps.

Best for partial shade would be all parallel but the current would be 38 amps and exceed the Jayco wire rating so the best you can do is the mixed series/parallel. In series if you shade one panel the output of the pair goes to zero, in parallel if you shade one panel of a pair the power is cut in half.

[Mopar_Earl]

Another option is to use 24v 200 watt panels. They will have less amps. So while the factory prep is limited to 30a you could run 800w at 24v and not overload the wiring. You can also upgrade the wiring to 6 or 4 gauge.

Rich 200w 24v has 5.83 short circuit amps
Rich 200w 12v has 10.2 short circuit amps

4 200w panels at 12v would be 40.8 max possible amps. To much for the factory wiring with all panels in parallel.

4 200w panels at 24v would be 23.32 max possible amps. Within the factory wiring with all panels in parallel.


Earl

[Scottenj]

Originally Posted by Mopar_Earl

Another option is to use 24v 200 watt panels. They will have less amps. So while the factory prep is limited to 30a you could run 800w at 24v and not overload the wiring. You can also upgrade the wiring to 6 or 4 gauge.

Rich 200w 24v has 5.83 short circuit amps
Rich 200w 12v has 10.2 short circuit amps

4 200w panels at 12v would be 40.8 max possible amps. To much for the factory wiring with all panels in parallel.

4 200w panels at 24v would be 23.32 max possible amps. Within the factory wiring with all panels in parallel.


Earl

I don't understand your math, a 200 watt panel at 24 volts is 8.33amps, 200/24 = 8.33 amps

800 watts at 24 volts is 33.33 amps, 800/24 = 33.33 and that would be over the wire rating.

Plus when you size the controller it has to be sized for the output at around 14 volts to charge the batteries so >50amps, therefore a 60 amp controller, not a 20 amp one like the original poster was planning.

[Mopar_Earl]

Originally Posted by Scottenj

He still needs a bigger charge controller because whatever the input current is it gets down converted to around 14 volts to charge the batteries and that means >50 amp, so he needs a 60 amp charge controller, not a 20 amp one.

My post was strictly getting around the limiting 8ga factory prep wiring by using 24v panels. But yes, I agree the 100/20 controller wouldn't cut it on 12 or 24v panels in parallel of 4 200w panels.


Earl

[Scottenj]

Originally Posted by NYRV'R

Sorry if this is a repost but something happened with the internet gremlins and it did not appear my first post was submitted successfully.

I have some basic questions for the Solar Wizards of the group.

I plan on install 4 (four) 200 watt solar panels on the roof, connecting them to a Victron MPPT 100/20 in the basement storage area utilizing the Jayco solar prep wires (8 awg). I will place disconnect and fusing between the panels and the MPPT and again between the MPPT and the batteries. Lastly, I would place a shunt and monitor off the neg side of the batteries to monitor usage.

Is it that simple? What am I missing?

Will the onboard standard Jayco converter/charger work with Lithium batteries for now? I plan on having 4-6 lithium batteries in the upfront storage area.

Next year after my wallet has a rest, I want to install a Victron Multiplus 3000 converter charger and Smart Phase Selector Switch.

Yes I have a res fridge hence the need for 800 wats of solar and probably 6 lithium batts.

Thanks in advance for your replys and recommendations.

If you go with Battle Born the Jayco controller won't damage them but they wont ever charge all the way, at least that was my experience. If you have the Progressive Dynamics panel you can swap the converter to a lithium one in about 15 minutes.

[Mopar_Earl]

Originally Posted by Scottenj

I don't understand your math, a 200 watt panel at 24 volts is 8.33amps, 200/24 = 8.33 amps

800 watts at 24 volts is 33.33 amps, 800/24 = 33.33 and that would be over the wire rating.

Plus when you size the controller it has to be sized for the output at around 14 volts to charge the batteries so >50amps, therefore a 60 amp controller, not a 20 amp one like the original poster was planning.

As stated, those are rich brand numbers for 200w 12v and 200 24v panels. No magic, factory specs.


Earl

[Mopar_Earl]

Originally Posted by Mopar_Earl

As stated, those are rich brand numbers for 200w 12v and 200 24v panels. No magic, factory specs.


Earl

Rich 200w 24v
Maximum Power(Pmax): 200W
Maximum Power Voltage(Vmp): 37.6V
Maximum Power Current(Imp): 5.32A
Open Circuit Voltage(Voc): 45.4V
Short Circuit Current(Isc): 5.83A
Maximum System Voltage(Vmax): 1000V DC
Weight: 26.5 lbs
Dimensions: 58.7 x 26.8 x 1.4 in

Rich 200w 12v
Maximum Power(Pmax): 200W
Maximum Power Voltage(Vmp): 20.4V
Maximum Power Current(Imp): 9.80A
Open Circuit Voltage(Voc): 24.3V
Short Circuit Current(Isc): 10.2A
Maximum System Voltage(Vmax): 1000V DC
Weight: 26.5 lbs
Dimensions: 58.7 x 26.8 x 1.4 in

Right from Rich, 5.83 amps on 24v panel and 10.2a on 12v panel. That's how you keep your 8ga wiring, run 24v panels.

Earl

[Scottenj]

Originally Posted by Mopar_Earl

Rich 200w 24v
Maximum Power(Pmax): 200W
Maximum Power Voltage(Vmp): 37.6V
Maximum Power Current(Imp): 5.32A
Open Circuit Voltage(Voc): 45.4V
Short Circuit Current(Isc): 5.83A
Maximum System Voltage(Vmax): 1000V DC
Weight: 26.5 lbs
Dimensions: 58.7 x 26.8 x 1.4 in

Rich 200w 12v
Maximum Power(Pmax): 200W
Maximum Power Voltage(Vmp): 20.4V
Maximum Power Current(Imp): 9.80A
Open Circuit Voltage(Voc): 24.3V
Short Circuit Current(Isc): 10.2A
Maximum System Voltage(Vmax): 1000V DC
Weight: 26.5 lbs
Dimensions: 58.7 x 26.8 x 1.4 in

Right from Rich, 5.83 amps on 24v panel and 10.2a on 12v panel. That's how you keep your 8ga wiring, run 24v panels.

Earl

So the 24 volt panel actually is 37.6 volts at max power, that explains it.

I didn't realize Rich was referring to a brand of solar panel.

[NYRV'R]

Thanks Klassic, good catch.

[NYRV'R]

Thanks for the suggestions on the MPPT. I have adjusted my plan to a Victron 150/60 MPPT.

[NYRV'R]

Yes I am going with Battle Born and will most likely jump into the Victron Multiplus 3000 charger/converter to upgrade from the PD charger/converter.

[Scottenj]

Originally Posted by NYRV'R

Yes I am going with Battle Born and will most likely jump into the Victron Multiplus 3000 charger/converter to upgrade from the PD charger/converter.

Make sure you disable the internal converter if you do that.

[Sola123]

With all this discussion...it seems I will be safe ......I am planning on 525 watts....3 panels at 175 watts @ 8.98 amps each max.....all in parallel...using the Jayco pre wire.....to a 40 amp controller.....should I be safe with this setup to not melt the 8 ga wire from factory.....???.....controller paperwork says up to 600 watts......any help much appreciated....

[Scottenj]

Originally Posted by Sola123

With all this discussion...it seems I will be safe ......I am planning on 525 watts....3 panels at 175 watts @ 8.98 amps each max.....all in parallel...using the Jayco pre wire.....to a 40 amp controller.....should I be safe with this setup to not melt the 8 ga wire from factory.....???.....controller paperwork says up to 600 watts......any help much appreciated....

Assuming 8.98amps is the current at max power, then the voltage at max power is 19.49. Make sure on the spec sheet that is the max current.

You are putting 26.94 amps through wire rated for 30 amps, that should be OK although personally I would want more margin.

At the controller the 19.49 volts and 26.94 amps will be converted to something like 36.46 amps at 14.4 volts, once again OK but close to the limits.