Mixed Solar Panels and Mixed Solar Controllers - Solution?

[Yoda]

I decided to start a new thread so other folks can learn also to keep the existing threads on track. First the sources I used - there were others, but these best sum up my situation.

https://solarpanelsvenue.com/mixing-solar-panels/
https://www.youtube.com/watch?v=rBbVIiOBuT4 They have a series of videos. One shows why the MPPT controller is better.

About 75% of the way through the document is a section titled How to squeeze more solar power from different solar panels by breaking the best practice rules?

This is my situation exactly. I have the 160W system, don't want to waste it, got new and need to maximize what I have.

What I have now - Go Power 160W panel with a GP-PMW-30 same specifications as this https://gpelectric.com/products/30-a...ler-bluetooth/ It has been doing fine with my 2 -12V interstate deep cycle battery's - dealer installed.
Panel specifications from Go Power

SPECIFICATIONS
Rated power (Pm)	160W
Maximum power voltage (Vmp)	18.60V
Maximum power current (Imp)	8.60A
Open circuit voltage (Voc)	22.50V
Short circuit current (Isc)	9.29A
Power coefficient	–0.39% / °C
Voltage coefficient	–0.31% / °C
Current coefficient	0.045% / °C
Max power tolerance	+/- 5W
Cell type	Monocrystalline
Module efficiency	16.4%
Series fuse rating	20A
Maximum system voltage	1000VDC (UL / IEC)
Weight	26.4 lb (12 kg)
Dimensions	59.1 x 26.3 x 1.97 in 1500 x 668 x 50 mm
Frame type / material	Clear anodized aluminum frame

Power Specifications calculated at STC:

• Irradiance: 1000 W/m2
• Cell Temperature: 77 °F (25 °C)
• Air Mass: 1.5

What I am trying to do

I plan to upgrade to Battle Born or other Lithium battery's, so I need a compatible solar controller. My exiting one will work if set to AGM per Battle Born but not get them to full charge.

On Black Friday I found a great deal on 2-190W Go Power panels

SPECIFICATIONS
Rated power (Pm)	190W
Maximum power voltage (Vmp)	20.4V
Maximum power current (Imp)	9.45A
Open circuit voltage (Voc)	24.09V
Short circuit current (Isc)	9.98A

*These were taken off the back of the panel and dont exactly match the specifications on thier web page.

I also picked up the GP-PWM-30-UL controller that is Lithium compatible - Wrong choice as you all have told me I think I can return the one I got (waiting to hear)

After reading the above document (and others) and to not loose output from the existing panel (or remove it - a real pain) I need to run separate controllers and tie them in parallel at the battery's. It also appears to get the best out of the new panels and for my future Lithium battery bank I should wire the two 190W panels in Series and get a MPPT charge controller. In short if you have mixed panels and cant match them up using series/parallel combinations, its best to run them through separate solar controllers. I hope I got that right?

From what I have read leaving the existing system in place wont hurt anything - its there and can operate as a backup in case anything goes wrong. Removing it will leave holes including a large hole in my living room wall.

So my problem now is I really know nothing about MPPT controllers or how to size them.

My 2 -190 watt panels in series per the resources will possibly produce 40.8V @ 9.95 amps. However at Max output (short circuit) 48.18V @ 9.98 amps. I am not sure which to use for sizing, but for now I will go with the higher numbers. If I understand the advantage of the MPPT controller is that it will reduce the voltage to the battery specifications and increase the amps accordingly. Increasing the amps is something the PWM controller can not do - It matches the voltage to the battery profile selected only and passes the amps through. Not as efficient. Did I get that right? Is series the right way to go? I remember being told that the panel voltage output need to be significantly higher than the battery voltage for proper charging.

So it appears I need a MPPT controller rated at about 50V and say 15 amps to be safe - correct? For the future as panels keep changing, I should probably plan on a second MPPT unit . I would need to remove the existing 160 watt panel at that time to have room I believe. However I will probably be fine with what I have, especially with the PWWM controller. I am not full timing and with the 5th wheel I have there is not a huge power need - only a 30A unit.

The only ones I have looked at are Victron https://invertersrus.com/product/vic...ppt-100-30-50/ would the 75 /15 work? It has the bluetooth built in so I can program it - assuming I learn how to use my smart phone.

Another plus side it will work with the Multiplus and color control if I go that way.

Thoughts? Recommendations?

Thanks Keith

[ncitro]

Yoda That logic seems sound. I am pretty sure that Victron should work, but I would lay out your plan to your dealer and make sure they agree. Make sure you get the Smart Solar, thats the one with bluetooth built in. I have the 150/100 for my 1200 watts of panels. I am wired in three sets of two series panels, so should be a max of 50v @ 30 Amps, but I wanted room to add more panels and the extra cost from the next model down was not huge. Definitely lean of your dealer for advice, I had many conversations with AM Solar about my setup before I pulled the trigger.

[Yoda]

Yoda That logic seems sound. I am pretty sure that Victron should work, but I would lay out your plan to your dealer and make sure they agree. Make sure you get the Smart Solar, thats the one with bluetooth built in. I have the 150/100 for my 1200 watts of panels. I am wired in three sets of two series panels, so should be a max of 50v @ 30 Amps, but I wanted room to add more panels and the extra cost from the next model down was not huge. Definitely lean of your dealer for advice, I had many conversations with AM Solar about my setup before I pulled the trigger.

Whew!!!!!!!!

I though you were going to say I was nuts again

I will definitely talk to the dealer and possibly consider a larger unit for the future. Its amazing when you re-read something you learn twice as much.
Thanks for the help
Keith

[ncitro]

Whew!!!!!!!!

I though you were going to say I was nuts again

I will definitely talk to the dealer and possibly consider a larger unit for the future. Its amazing when you re-read something you learn twice as much.
Thanks for the help
Keith

Lol I would never call you nuts

No worries, I totally get where you are coming from. I think you are on a good path, but given the specifics of mixing the controllers I would defer to a dealer with more experience in that portion. The part that worries me is the old controller is going to be running at a lower voltage than the new one, so I am not sure how that is going to play out.

[Yoda]

Lol I would never call you nuts

No worries, I totally get where you are coming from. I think you are on a good path, but given the specifics of mixing the controllers I would defer to a dealer with more experience in that portion. The part that worries me is the old controller is going to be running at a lower voltage than the new one, so I am not sure how that is going to play out.

Go Power said it would contribute to the battery charge until the battery reached 14.4V then the higher output controller would control. But I will check that with the Victron folks

[TucsonJim]

Go Power said it would contribute to the battery charge until the battery reached 14.4V then the higher output controller would control. But I will check that with the Victron folks

That is correct. You could conceivably have three charging sources at the same time. Shore power, Solar 1, and Solar 2. Or TV power, Solar 1, and Solar 2. I know it's not intuitive, but they really do play well together. Or, you could selectively power down one or two of the sources and rely on whichever one you set as primary.

Jim

[Yoda]

That is correct. You could conceivably have three charging sources at the same time. Shore power, Solar 1, and Solar 2. Or TV power, Solar 1, and Solar 2. I know it's not intuitive, but they really do play well together. Or, you could selectively power down one or two of the sources and rely on whichever one you set as primary.

Jim

Thanks Jim

Good news - Etrailer will take the controller back - I'm out expensive shipping, but lesson learned. So now to choose the correct MPPT. I have an inquiry into invertersRUs as their sale is still on. https://invertersrus.com/product-cat...ictron-energy/ Code IRV2VICTRON15 still works for 15% off.

BTW - do I need a DC-DC converter for my new to come Ford F350? or is that a whole can of worms? I have searched and read on it, but don't want to do the big wiring upgrade - for now. Just wondering if it would work with the stock system.

Anyway

Thanks Keith

[Yoda]

I just heard back from invertersRUs they wanted to talk to me so I sent my phone number. 3 minutes later Steve was on the line verifying what I was wanting to do. Said it would definitely work, but recommended I go the next size up 100/20 due to the PV power out of the panels. I went and checked the specifications and it makes sense. If I want to plan for a future (2 more 190's) to get the 100/50. Or he agreed depending when that might be and just get the required MPPT for the new panel ratings.

He then mentioned as Victron is Europian based their product ratings on (VA) not just amps so the Multiplus 2000 is not a 2000w inverter but 1600Watt in our system. Didn't know that so I learned a new thing. Looks like I need the 3000 which is rated 2500W If I go this route. Steve also mentioned if I was not smart phone savvy to go with the Color Control over the touch 50 and GCX to monitor my MultiPlus when the time came.

So back to budgeting.

[ncitro]

That sounds good, and I am glad they made contact with you. Sounds like they are giving you some good advice. I forgot about the VA vs Watt issue, one of the reasons its good to speak with your dealer. The surge rating is in watts though. 4000 watts for the 2kVA unit and 6000 watts for the 3kVA unit. Depending what you are looking to power you still might be okay with the 2kVA. I have the 3kVA and its a beast. It runs everything I throw at it with no issue. I have even used it to run my AC unit with no EasyStart as a test and it did so just fine.

As far as the DC to DC charger it is not needed, its a get it if you want it. It was a huge improvement for me. I have the 40 amp version and did the wiring upgrade. It allows me to get back a ton of power on driving days. The solar does great, but on rainy drive days (more often than I would have thought) truck charging is all there is. If we are going to from a dry site to a Walmart stop over or something, its good to get there charged up and no need to break out the generator. That said Guest installed the 20 amp Renogy DC to DC charger and was able to use the factory truck wiring.

All that said it's not required. I ran my rig with 4 golf cart batteries for two years, and my four Lithiums for a year with just the stock charging system. No issue to the truck, however the most charge I ever saw going into the batteries from the truck was a paltry 7 amps. If my lithiums were at half, and I was using no power in the trailer while driving, it would take 25 hours to charge them. I am running a residential fridge, so the upgrade made good sense for me. If you do not plan to do a lot of dry camping, or dry stops on drive days it may not be an issue for you. I can tell you its been a godsend for us on the rainy or cloudy drive days.