Replace/Upgrade Factory Solar 260RD?

[nogascans]

We own a 2021 260RD that came equipped with a Furrion 165W solar panel and 30A controller. When I upgraded the existing 12V/100A lead acid battery to a LiTime 280Ah LiFePO4 battery, I had some issues with Furrion controller. I replaced that unit with a LiTIme 60A 12V-48V smart solar controller. Functionally, for the light loads and short trips, this has been fine to keep the internal 12V Fridge happy. RV also came with inverter wiring package, but we are not currently looking to add inverter.

Specs as follows:

System Voltage 12V/24V/36V/48V, Rated charging voltage 60A, Rated load current 20A. Max solar panel input as follows: 900W for 12V/1800W for 24V/ 2600W for 36V/3200W for 48V, Max solar input voltage 150V.

We are looking to do some more extensive camping this summer, and possibly a day or two boondocking and are interested in upgrading the solar package on roof to more capacity. Probably stay with the Z-Clip design for mounting since existing panel is secured that way.

I have been looking at the new Renogy 200W ShadowFlux (w/Anti-Shading tech N-Type) panels as a replacement.

Specs as follows:

Max Power at STC (200W). Open Circuit Voltage (36.5V). Short Circuit Current (6.86A). Optimum Operating Voltage (31.3V)

This panel has a very similar footprint which would make replacement a snap. Looking at roof, with the dual AC/venting layout, we could add an additional (3) three panels. I was thinking that if I added the extra panels, I would need to wire them as each two panel group in parallel, and then use MC4 branch connectors to tie each 2-panel group back to solar connection on roof, correct?

Is this possibility our best solution for wiring up with the current equipment (12V battery)? If we were to add an additional battery (same), would there be any benefits (other than additional storage) like running at higher voltage?

Thanks in advance for any feedback!

Sincerely,

David

 

[Soundsailor]

While I'm not familiar with that controller, your plan sounds fine. When I upgraded my solar system, I got a Victron controller, which has been a great investment. I used eight 100-watt panels coupled with the original 180-watt panel (I am only getting 100 watts from it, but it was already there). The nine panels are wired in series (three each) and then parallel. You'll need to pay attention to the limited capacity of the cable going from the roof to the controller.

 

[nogascans]

Soundsailor,

thanks for the feedback. I had it on my list to check the gauge of that run to make sure there wouldn't be an issue with amperage. Seem to recall when I did the replacement MPPT that it was a 10 gauge wire, but I do need to re-check.

On your rig, did you stay with a 12V (battery) bank/system or go to a higher voltage? Inverter?

Sincerely,

David

 

[Soundsailor]

Yes, as far as I know, it is 10 gauge. When I did my project, I didn't know much about solar, so I stayed with 12-volt. I believe @SolarPoweredRV recommends 24-volt, I might have gone that way if I had it to do over.

I do have a 3,000-watt inverter. In retrospect, I probably would have gone with the Renogy 2,000-watt inverter with a built-in ATS.

 

[Soundsailor]

Some info on my install here: 2022 260RD 12Volt LiFePO4/Solar/Inverter Install

 

[Rovers]

Soundsailor,

thanks for the feedback. I had it on my list to check the gauge of that run to make sure there wouldn't be an issue with amperage. Seem to recall when I did the replacement MPPT that it was a 10 gauge wire, but I do need to re-check.

On your rig, did you stay with a 12V (battery) bank/system or go to a higher voltage? Inverter?

Sincerely,

David

Just a thought… if you wire your panels in series then you don’t need heavier wire since you’ll be adding volts together and keeping the amps the same. Only question then becomes the voltage capacity of your charge controller which I don’t see in your specs. Given the Renogy panels’ optimum voltage of 31 volts your charge controller would need to be able to handle 125 volts or so (allowing for some headroom.)

Your panel wiring would be straightforward: Neg from panel 1 to Pos on panel 2; POS on panel 1 to charge controller; Neg on 2 to POS on 3; Neg on 3 to Pos 4; Neg on 4 to charge controller.

I have the same layout as you but different panels - 4, 200W panels wired in series as above to a Victron 150/60 charge controller (rated for 150 volts and 60 amp input.)

You’ll save on wiring and should be able to use MC4 connectors right to your existing solar panel wiring assuming it’s 10 gauge or thicker.

My 2 cents,

Bob

 

[Redapple63]

Just a thought… if you wire your panels in series then you don’t need heavier wire since you’ll be adding volts together and keeping the amps the same. Only question then becomes the voltage capacity of your charge controller which I don’t see in your specs. Given the Renogy panels’ optimum voltage of 31 volts your charge controller would need to be able to handle 125 volts or so (allowing for some headroom.)

Your panel wiring would be straightforward: Neg from panel 1 to Pos on panel 2; POS on panel 1 to charge controller; Neg on 2 to POS on 3; Neg on 3 to Pos 4; Neg on 4 to charge controller.

I have the same layout as you but different panels - 4, 200W panels wired in series as above to a Victron 150/60 charge controller (rated for 150 volts and 60 amp input.)

You’ll save on wiring and should be able to use MC4 connectors right to your existing solar panel wiring assuming it’s 10 gauge or thicker.

My 2 cents,

Bob

Agree with this with one twist. Do a 2s2p configuration. 2 strings of 2 panels in series, tied together in parallel.

 

[Redapple63]

I hit the post reply button too soon. I wanted to elaborate on the 2s2p configuration. Connecting 2 strings of 2 panels in series will double the voltage (36.2 x2) 72.4 and keep the amperage the same I think it was 6.72 or something close to that. Then you connect the two strings in parallel to double the amperage to 13.44.

That configuration would give your solar charge controller 72.4 volts and 13.44 amps. It would also minimize panel loss to shading, and it’s easily run with 10 awg wire down to the controller. I think you would be very happy with that set up.

Bill

 

[nogascans]

Just a thought… if you wire your panels in series then you don’t need heavier wire since you’ll be adding volts together and keeping the amps the same. Only question then becomes the voltage capacity of your charge controller which I don’t see in your specs. Given the Renogy panels’ optimum voltage of 31 volts your charge controller would need to be able to handle 125 volts or so (allowing for some headroom.)

Your panel wiring would be straightforward: Neg from panel 1 to Pos on panel 2; POS on panel 1 to charge controller; Neg on 2 to POS on 3; Neg on 3 to Pos 4; Neg on 4 to charge controller.

I have the same layout as you but different panels - 4, 200W panels wired in series as above to a Victron 150/60 charge controller (rated for 150 volts and 60 amp input.)

You’ll save on wiring and should be able to use MC4 connectors right to your existing solar panel wiring assuming it’s 10 gauge or thicker.

My 2 cents,

Bob

Bob, input voltage on the MPPT is rated at: Max. Solar Input Voltage- 150V

Sincerely,

David

 

[huntindog]

The OP needs to read this link;Mixing solar panels – Dos and Don’ts • SOLAR POWER SECRETS

 

[nogascans]

The OP needs to read this link;Mixing solar panels – Dos and Don’ts • SOLAR POWER SECRETS

Thanks for link. I had already decided that the differences between the new 200w Renogy panels and factory 165w Furrion panel was too much to have any benefit.

I was able to remove the factory 165w panel and remounted a new Renogy panel in its general location on drivers side next to front AC unit, and a 2nd on passenger side roughly in same place (slightly more rearward). Have both working and at peak in SE GA sun I am hitting around 350 watts (measured thru LiTime MPPT App).

I have also cleaned up my front storage bay and associated electrical. Plan on adding a 2nd 270Ah LiTIme battery to setup later this week for some added storage.

I understand the basics of the wiring design, and currently I have a 300A T-fuse within 6" of 280Ah battery positive (+). When I add the second 280Ah battery, which I plan to stage right next to primary, I will end up with a pair of short interconnect cables (12V use) along with moving battery ground negative from old battery (-) to new battery (-).

With the addition of new battery, should I be looking at adding a MBRF fuse to either (or both) of the battery positives (in addition to the existing 300A T-fuse)? If so, any suggestions on fuse size? Using #2 copper inverter wire for both Battery (+) and (-).

Thanks in advance for any help!

Sincerely,

David