320w panel question.

[Boundless Buckeyes]

Wanting to add solar to my new (Late October 23) 2022 Paradigm 295mk. Solar prepped. 2000w inverter. The super solar package from Alliance, has an 800w max 60amp. Renogy charge controller, but Alliance uses 3-320w panels. Is this because no panel really works at 100%? What happens when you send more than the max for the controller? Should I just buy 4 -200w panels? I've purchased most of what I need to make the super solar package, Renogy 60a controller, 300amp hr. worth of 12v lithium, fuses, cables, MC4 connectors. Just needing some help with what the best panel might be. One last question. Is the 320w panel 12v or 24v and does that really matter? I would be running the 4 panels in series- parallel(24v) and the 3 panels in parallel.

 

[Oregon_Camper]

** I am not a solar professional...please validate all numbers yourself **

OK...there is a lot to unpack in your question. Alliance must use a different controller when then install 3x320 watt panels as watts increase regarless of series or parellel connections.

Do you have any solar now? Are you hoping to have 7 panels, as you wrote... "I would be running the 4 panels in series- parallel(24v) and the 3 panels in parallel."

If your plan is 4x320w panels you need to get a much larger MPPT controller (like Victron 250/100) or wire sets of panel in series to two different smaller controllers, like the Victron 150/60
Here is how I calc your set up using just the single Victron 250/100 controller

 

[Boundless Buckeyes]

Dang, that was fast. Thanks for the response. Now for me to clarify some things. It should have read 4–200-watt Renogy panels in a series -parallel or 3–320-watt Renogy panels in a parallel. Not both sets of panels. The 8awg wire from Alliance in the solar prep running from the roof port to the battery bay should be ample to handle either set of panels. The Renogy 60amp charge controller seems a little undersized for the 320-watt panels, but that is the controller that Alliance uses for those three panels in the super solar package. I know the safe bet is with the 4-200-watt panels, but if the 3-320-watt panels work for Alliance why not for me? My guess would be that no solar panel produces at the max rating, and even if it did, not all of the panels on an RV would produce 100% at the same time. Keeping the total watts being delivered at any given time to less than the 800-watt max of the controller. Trying to understand Alliance thought process. Would the additional 160-watt additional power burn up the controller or just not be processed? Having the extra 160-watts would help on cloudy days.

 

[Boundless Buckeyes]

After talking to a Renogy "tech"!! I got nowhere. Just someone reading from a manual and had no idea how to help. I turned to An AllianceRV professional (Carter Cantrell). What a wealth of information. The man knows his stuff about AllianceRV products. And he took his time to make sure we were both on the same page. Listened and offered up suggestions to make sure I was comfortable and being safe in what I will be customizing my 2022 Paradigm 295MK with.

Solar here I come.
Thank You Carter Cantrell

 

[Oregon_Camper]

After talking to a Renogy "tech"!! I got nowhere. Just someone reading from a manual and had no idea how to help. I turned to An AllianceRV professional (Carter Cantrell). What a wealth of information. The man knows his stuff about AllianceRV products. And he took his time to make sure we were both on the same page. Listened and offered up suggestions to make sure I was comfortable and being safe in what I will be customizing my 2022 Paradigm 295MK with.

Solar here I come.
Thank You Carter Cantrell

and what did he recommend for the solar MPPT controller if you were to have a total of 3x320w panels?

 

[Boundless Buckeyes]

Wasn't really looking for recommendations. I was trying to understand how AllianceRV was using the Renogy 60amp MPPT controller and 3-320-watt panels in the super solar upgrade. In theory the 960 total watts is over wattage for the controller. In real world application you would be hard pressed to generate those 960 watts at any given time. Panels notoriously underdeliver the specified wattage. So between using 4-200-watt panels vs 3-320-watt panels, your chances of generating closer to 800 watts of usable power for the Renogy 60amp controller, is better with the 3-320-watt panels. For me, I already have the same Renogy 60amp controller that AllianceRV uses in their Paradigms and didn't want to burn it up with too many watts but wanted to use all of its capacity. I'll update when I get the everything installed later this spring. Still snowy and cold here in Ohio. I won't be changing, or adding any outlets already connected to the inverter. Not trying to run the air conditioner. Just looking to boon dock a little more comfortable and longer than overnight.

 

[Oregon_Camper]

I would highly recommend a different MPPT controller. With 3x320w panels you have the potential to be 20% over the rated max for that controller. This will most likely occur as you are driving on a freeway in the summer, with no trees shading the panels.

Here is your numbers with the 3x320w panels and the Renogy controller. For sure you want to wire them in series vs parrallel.

 

[HCL]

Oregon Camper
I'm confused because the super solar package is with 3x320wt panels and Renogy 60amp MPPT controller directly installed from Alliance, at least on my Valor 36v11 and your saying the controller is too small to handle this load or has the potential to be to small? Or did I misunderstand?
Thanks
Mike

 

[Oregon_Camper]

Oregon Camper
I'm confused because the super solar package is with 3x320wt panels and Renogy 60amp MPPT controller directly installed from Alliance, at least on my Valor 36v11 and your saying the controller is too small to handle this load or has the potential to be to small? Or did I misunderstand?
Thanks
Mike

First...as I stated above....** I am not a solar professional...please validate all numbers yourself ** I provide numbers I know are mathmatically correct via stated limits of devices. I am more than willing to listen and learn from others if my thinking is incorrect.

Based on the stated specs for the panel and the controller, if you were to hit stated wattage from 3x panels, then yes you would be exceeding the rated watts for that controller by 20%. Some will say the MPPT controll will simply ignore the wattage over stated limit (in your case potentailly 160 watts). If true, then you're ok. However, getting a MPPT controller that can use all the watts, will only help in creating more power for the batteries. Would you pay for 6 gallons of gas but only put in 5 gallons? I struggle with the fact there are stated watt limits. If the controller does in fact simply ignore the additional watts, then why even list a max?

This seems like a question to ponder more over a few beers around a campfire

I would replace the Renogy with a Victron 150/70 MPPT controller. They are ~$350 on Amazon. Here is the same calculations, but with the Victron 150/70 unit

 

[HCL]

Jim
Thanks, I agree with beers and campfires!
Not disputing your numbers at all and agree with you. I looked at all the numbers hard before we went with the solar upgrade and after talking with folks and in my mind, Renogy or Alliance or both knew and know (or they would not keep mounting that system) that those 320 panels were never efficient enough to be a danger of overpowering that controller or wires and causing a problem, ie fire etc. Tons of stuff to factor in, how clean the panels are, line loss, sun angle, brightness, temp of sun, temp of wires, draw on system etc.
Anyhow hope to link up with ya on the road sometime sounds like we could have some interesting conversations.
Thanks
Mike

 

[Oregon_Camper]

Jim
Thanks, I agree with beers and campfires!
Not disputing your numbers at all and agree with you. I looked at all the numbers hard before we went with the solar upgrade and after talking with folks and in my mind, Renogy or Alliance or both knew and know (or they would not keep mounting that system) that those 320 panels were never efficient enough to be a danger of overpowering that controller or wires and causing a problem, ie fire etc. Tons of stuff to factor in, how clean the panels are, line loss, sun angle, brightness, temp of sun, temp of wires, draw on system etc.
Anyhow hope to link up with ya on the road sometime sounds like we could have some interesting conversations.
Thanks
Mike

I started a solar group on Facebook a few years ago (just under 62,000 members now) and the answer I see there is it is ok to go over on watts....IF you're using a Victron controller. A few said they had issues when trying this with Renogy. Now...who knows what panels they were using and perhaps Alliance knows these 320w Renogy panels will never hit more than say ~250w each, which means you're pefectly fine.

 

[CornCrib]

While I don't have the same level of experience and knowledge as Jim, I do concur with his math as it is consistent with my understanding and how we were taught at the NRVTA Solar Class. I went with 4 of the Renogy 320w panels (2s, 2p), and chose the Victron 150/100 after applying the same math logic as Jim has shown in his work above (@Oregon_Camper , somewhere a former math teacher of yours is smiling for showing your work). So far, I've seen a max of 920 watts produced by the potential of 1280 watts available (72%). That was full sun in mid Feb in Florida, so it will be interesting to see how much closer to 100% I can get as the sun is directly above me later this year.

 

[Oregon_Camper]

While I don't have the same level of experience and knowledge as Jim, I do concur with his math as it is consistent with my understanding and how we were taught at the NRVTA Solar Class. I went with 4 of the Renogy 320w panels (2s, 2p), and chose the Victron 150/100 after applying the same math logic as Jim has shown in his work above (@Oregon_Camper , somewhere a former math teacher of yours is smiling for showing your work). So far, I've seen a max of 920 watts produced by the potential of 1280 watts available (72%). That was full sun in mid Feb in Florida, so it will be interesting to see how much closer to 100% I can get as the sun is directly above me later this year.

Question...how long does it take your system to wake up in the morning? I ask, as you have 66 volts total going to the controller vs 132 if they were in series. I know the controller need to hit a little over 17 volts to start charging.

BTW...I did LOVE math in High School and College...might have something to do with my EE and CS degree's.

For those wondering, here is CornCribs numbers, using the 2S-2P wiring setup he has with the Victron 150/100 controller.

 

[CornCrib]

I haven't noted the exact timing, but I'll take a look at my VRM history and see if I can determine exact timing. Just anecdotally, it seems to start and complete charging pretty quickly in the AM, then maintain it until around 5ish ... sunset here is just after 6. Even in a heavy rainstorm yesterday, I was still pulling a small amount from the solar panels.

 

[tmartin000]

Remember, Victron controllers will simply work based in their rating, regardless of how much is over in voltage or current. Which means whatever you have, it will work to its maximum capacity rating. All other current or voltage is simply ignored. The problem is you give up free energy if it’s not perfectly sized, but again, Victron will just run at its max rating and ignore anything above.

 

[terminalhour]

Wasn't really looking for recommendations. I was trying to understand how AllianceRV was using the Renogy 60amp MPPT controller and 3-320-watt panels in the super solar upgrade. In theory the 960 total watts is over wattage for the controller. In real world application you would be hard pressed to generate those 960 watts at any given time. Panels notoriously underdeliver the specified wattage. So between using 4-200-watt panels vs 3-320-watt panels, your chances of generating closer to 800 watts of usable power for the Renogy 60amp controller, is better with the 3-320-watt panels. For me, I already have the same Renogy 60amp controller that AllianceRV uses in their Paradigms and didn't want to burn it up with too many watts but wanted to use all of its capacity. I'll update when I get the everything installed later this spring. Still snowy and cold here in Ohio. I won't be changing, or adding any outlets already connected to the inverter. Not trying to run the air conditioner. Just looking to boon dock a little more comfortable and longer than overnight.

I think I’m on the same journey as you are, Boundless.
In the process of understanding Alliance’s use of the Renogy 60A mppt, I understand the 800W rating is for 12V panels. I believe the 320W panel that they use is 24V. When using 24V panels with the Renogy 60A mppt the max wattage increases to 1600W, well within the limitations for 3 of the 320W panels. Again, this is just from me trying to research the crap out of this stuff

 

[Oregon_Camper]

I think I’m on the same journey as you are, Boundless.
In the process of understanding Alliance’s use of the Renogy 60A mppt, I understand the 800W rating is for 12V panels. I believe the 320W panel that they use is 24V. When using 24V panels with the Renogy 60A mppt the max wattage increases to 1600W, well within the limitations for 3 of the 320W panels. Again, this is just from me trying to research the crap out of this stuff

You're confusing solar panel voltage vs nominal system voltage of the RV's power bank.

 

[Boundless Buckeyes]

Like Oregon-camper said. If your batteries are 24volt, the wattage of the charge controller can accept is 1600 for the 60amp Renogy. Not the voltage of the panel.

 

[tmartin000]

After many years of installing equipment for a living, if it were me, I would have the factory install as many 320w panels as you can afford. It’s so easy to manipulate how you want those panels to be wired with the way alliance does their wiring down to the Renenegy unit, that creating whatever solar system you want is so dang easy. And the reason I would have them do the panels is because if it leaks it’s on them and it’s the hardest part to do for an RV owner to do. (Mounting wiring and waterproofing.). Then I would just remove the Renergy piece and buy a far better brand that’s more reliable at 10 times the features that are usable. There are many that can tell you exactly what to use and it’s easier and be done with it. The funny part is the hardest part already done for the potential installer or RV owner. It’s literally plug-in play at that point.