Adding solar panel for Micro Minnie FLX

[Marine359]

This is an excellent explanation of why both Vmp and Voc are important, lifted from an energy forum:

Voc is the open circuit voltage which means it is the voltage the PV panel will measure when it is not connected to a circuit. So normally this will not be the case in a working system. But say you trip the PV breaker/fuse then Voc will apply. You might hit that high voltage around full sun (mid day for a norht facing array) if you then close the breaker or reconnect the fuse, but it will quickly be pulled lower by anything using that power (charging the batteries, using the lights, etc.)

Vmp on the other hand is the the maximum power under load. The load is trying use the power, pulling down the voltage. So you normally see that Vmp is about 75% less that the Voc values. Except when there is a break (circuit breaker, fuse) this would be what you will see in your system.

[Herbiered]

Hello,

I have been reading many of the threads here regarding solar modifications in an attempt to gather information for my project. So today I joined the message board to share my upcoming solar addon project. I own a Winnebago Micro Minnie FLX 2108FBS. I purchased the travel trailer in April of 2022. I mostly camp where there is power hookups. I did do some boondock camping in Colorado this past fall. I was able to use a portable generator to assist in recharging the RV battery during the boondocking experience. I decided that I would increase my solar power production this spring before the camping season starts up. The solar system on my FLX contains Go Power solar products so I decided to stay with that brand. From the factory my RV has two Go Power 190 watt solar panels (GP-PV-190M) wired in series mounted on the roof, one Go Power MPPT 30 amp solar controller (GP-RVC-30-MPPT) installed in the storage pass through, one Go Power remote controller installed on the wall inside the RV, and a SAE/Zamp solar power port installed on the driver side of the travel trailer.

I am going to add a Go Power 190 watt solar panel (GP-PV-190M) on the roof of the RV, and wire it in series with the two current solar panels. Each solar panel has a Voc rating of 24.09. My total Voc will be 72.3 with the solar panels in series. The Go Power MPPT solar controller's max PV input is just under 100 volts. The amperage will not be an issue with each solar panel rated at 9.45 amps. The wattage I believe will be okay too. The Go Power MPPT is rated for a max PV input at 12 volts of 600 watts. All three solar panels will be wired into the factory Go Power MPPT solar controller.

I am going to add a Go Power 30 amp MPPT solar controller in the storage pass through. I will wire it in parallel with the current MPPT solar controller. I am going to disconnect the SAE solar port wiring from the original MPPT solar controller, and wire it to the new MPPT solar controller.

I am also going to use a portable solar suitcase. Go Power GP-PSK-200 portable solar kit. It contains two 100 watt panels. The portable kit does contain its own controller that I will have to remove from the suitcase kit since I will be wiring to the new 30 amp MPPT controller.

From what I have read on the Go Power remote controller user manual I should be able to address both MPPT solar controllers either with the remote controller in the RV or from the mobile phone app.

Well that is my planned additions to my Micro Minnie FLX solar system. I am including a rough wiring drawing that I tried to create on PaintShop software.

Let me know if you see any issues with my planned updates.

Thank you,

Larry

[electric]

I only see one issue here - controller amp rating is for the output side, not input side, which means it will cap it's output at 30A at battery voltage, averaging around 13.8V during bulk charge, which means cap power at 414W, which means you are not fully using your 3rd panel when it's full sun at the best angle. In reality PV panels rarely get to their full rating, so most of the time controller's limit of 414W will be pretty close to actual PV power output limit.

[Herbiered]

Thank you for the quick response. I appreciate your advice and input. I will report back in the spring when I perform the installation.

Thanks again,

Larry

[jrg3170]

Hi everyone - good discussion here. I have a 2024 FLX (2100 BH) - the solar on the side port read 13V which I assume means it is wired to the battery.

The side port wiring was easily accessible and after popping off the wire nuts I was able to add a new Victron charge controller right there. I'm using a 200W portable panel from Renogy. I did need to reverse the polarity as part of the MC4 to Zamp adaptor.

Two questions:

1) Any specific settings I need to adjust in the Victron app? I didn't see anywhere to specify battery type, etc... is this all automatically configured? I have the standard Lithionics 320ah battery.
2) Do I need to ground the solar charge controller?
3) Dumb question - the Lithionics battery can accept charge from two different solar charge controllers at the same time? Wow!

In looking at the Lithionics app I do see an increase of ~100W in net energy inflow after plugging in the solar on the side panel (Victron showed 130W production), so I'm assuming it's working properly and I'm getting separate, simultaneous power from both the 400W on the roof (2x200 factory panels) and the 200W suitcase. I can post screenshots of the volts and amps from both charge controllers if anyone is interested.

Overall I was a) surprised that the side port is not wired thru the Gopower charge controller and b) pleasantly surprised at how easy it was to mount and install the new, 2nd charge controller.

[Marine359]

Didn’t have an FLX, but I think this still applies. After the Victron app identifies your controller, you should go in and set it for Lithium. And, yes your controller should be grounded between controller and battery. Easy to do if you connect it to negative bus bar, which is then grounded to chassis. I never installed a breaker for my sidewall portable because you will just be pulling the plug often. A LFP ability to accept charge amperage from multiple sources, including two controllers is not unique to Lithionics. The bms will only allow the battery to accept its maximum rated charge amperage. It doesn’t care where that amperage is coming from. Case in point: it’s normal to have a converter/charger or inverter/charger connected to the battery at the same time as one or more charge controllers. Never an issue unless the inverter /charger is set such that total charge amperage exceeds battery input rating. But bms protects against over amping.