Solar on Impact 359

[Drazul]

A SolarFlex 200 system can be ugraded to a 400 watt system. But can the 200 watt panels be replced by 300-500 watt panels andm if yes, can two be connected? Figuring this out is really educational, but also . . . . you know.

[NH_Bulldog]

You will have a few technical limitations to consider: the physical size of the panels and the mounting hardware. The presence or lack of presence of a suitable penetration on the roof for the upgraded wiring. The capacity of the existing wiring from the roof and the likelihood that it is insufficient for the higher wattage. You will need to upgrade the solar charge controller from the existing 15A. Increasing solar capacity by that much usually means you will be buying and installing an inverter and shunt.

It’s all doable, but likely will require a good deal of time and expense. I have been shopping for a new 5th wheel and was thinking I might get by with a SolarFlex 200 but when I looked into what it would take to upgrade to a 400 or 600 system myself, I decided to have the factory do it instead. I don’t see where we would be doing any longterm off grid camping, so a 400i system will probably meet my needs for the foreseeable future.

[Drazul]

Thanx. Keystone website states that one can upgrade to two 300 watts panels, but a 30 amp solar controller is necessary. The wiring is 10 gauge so that should be sufficient because the panels are 12 gauge. I’m looking at two Renogy 320 watts 24 volts panels with a Victron 100/50 controller. I have three 100 ah Renogy lithium batteries. If I connect the panels in serial, it will not effect the amps so the existing 30 amp solar port should be sufficient. Since the Impact 359 appears to only power certain outlets with inverted power, and not the a/c, this should be doable, And given that the Impact is 39 feet log, space is not an issue. It think I am correction all this, but can always use advice.

[JRTJH]

If you haven't already, I'd recommend you read the Keystone SolarFlex Quick Start Guide at: https://keystone-rv-dealer-app.cdn.p...DF_QSG_WEB.pdf

On about page 15 is a question: Why can't I build out my SolarFlex 200 to be like the SolarFlex 400i ?

In Keystone's answer to that question you'll find their explanation to some of your limitations. They also provide a recommendation in that paragraph which will take you back to the SolarFlex 200 information page where you'll find an "expand your system" section where you'll find a list of factory recommended "upgrade options".

I'd start there, and then start weighing the "user recommendations" to supplement what the factory provides and their upgrade components.

[Stircrazy]

Originally Posted by Drazul

Thanx. Keystone website states that one can upgrade to two 300 watts panels, but a 30 amp solar controller is necessary. The wiring is 10 gauge so that should be sufficient because the panels are 12 gauge. I’m looking at two Renogy 320 watts 24 volts panels with a Victron 100/50 controller. I have three 100 ah Renogy lithium batteries. If I connect the panels in serial, it will not effect the amps so the existing 30 amp solar port should be sufficient. Since the Impact 359 appears to only power certain outlets with inverted power, and not the a/c, this should be doable, And given that the Impact is 39 feet log, space is not an issue. It think I am correction all this, but can always use advice.

is there any reason you're not looking at the renogy rover MPPT controller, I use the 40amp one in my camper and when I upgrade to larger panels in the 5th wheel, I will go with a renogy controler again.

[NH_Bulldog]

Just a thought; you mention that the current 200w panel has 12-gauge wiring and that the wiring from the roof is 10-gauge? If there is one 10-gauge wire from the roof, you cannot just add another panel and run two panels through that single 10-gauge wire, you will need to add a second 10-gauge wire or upgrade the existing 10-gauge to 8-gauge to accommodate the increased power. Like Stircrazy mentioned, a 40A controller (or larger) would also be needed.

For example;
14 AWG for 15A
12 AWG for 20A
10 AWG for 30A
8 AWG for 40A
6AWG for 55A

As for roof space, that is a question only you can answer. Between roof vents, AC units, attic vents, skylight(s) and tank vents, there may not be as much free space up there as you might think. It may require spreading the panels out across the roof as opposed to locating them in one central area. I would get the panel and mount measurements and cut a carboard template the same size and then head up to the roof and see what your layout might be and whether it is feasible for your situation.

[Drazul]

The solar connector port on the roof that connects to the solar panel controller is 10 gauge wire. However, the wire on the solar panel that connects to the solar connector on the roof (not to the controller) is 12 gauge. From what I gather, so long as the increased amps from adding a second solar panel do not exceed the capacity of the 10 gauge wire (30 amps), there should not be a problem. If the two solar panels are connected in serial, the amps do not increase and the 10 gauge wire should be sufficient. ?????

[ScottA]

Correct, when you wire panels in series you double the voltage but keep the amps the same. Parallel doubles the amps and keeps the voltage the same. Amps are what are important for wire size.


None of the above takes into account the other benefits or pitfalls of doing each - shading, bypass diodes etc.


The renology controller is the toyota vs the victron is the cadillac. (But with toyota reliability


Scott

[Stircrazy]

Originally Posted by NH_Bulldog

Just a thought; you mention that the current 200w panel has 12-gauge wiring and that the wiring from the roof is 10-gauge? If there is one 10-gauge wire from the roof, you cannot just add another panel and run two panels through that single 10-gauge wire, you will need to add a second 10-gauge wire or upgrade the existing 10-gauge to 8-gauge to accommodate the increased power. Like Stircrazy mentioned, a 40A controller (or larger) would also be needed.

For example;
14 AWG for 15A
12 AWG for 20A
10 AWG for 30A
8 AWG for 40A
6AWG for 55A
.

not necessarily, if you run them in series, you will not increase the amperage just the voltage, which is what I would do in his situation. he would still need a new controller that is a MPPT one to do it and to make sure that controler will handle the two panels in series which a renogy 40 amp will as it can handle two 24V panels in series without spending the extra money on the Victron if you don't need to.

[firestation12]

Originally Posted by Stircrazy

not necessarily, if you run them in series, you will not increase the amperage just the voltage, which is what I would do in his situation. he would still need a new controller that is a MPPT one to do it and to make sure that controler will handle the two panels in series which a renogy 40 amp will as it can handle two 24V panels in series without spending the extra money on the Victron if you don't need to.

I agree with stir crazy, putting the panels the OP described (320 watts 24 volts) in series, will easily be within the capabilities of the 10 gauge wire. I would only suggest buying panels with a higher voltage output. Two 37.5 volt panels in series is 8.33 amps. The higher voltage panels begin to output a voltage (suitable for charging your battery bank) sooner in the morning and later before sunset. As long as the solar controller is rated to handle the voltage output of the panels you’ll be ok.

[Stircrazy]

Originally Posted by firestation12

I agree with stir crazy, putting the panels the OP described (320 watts 24 volts) in series, will easily be within the capabilities of the 10 gauge wire. I would only suggest buying panels with a higher voltage output. Two 37.5 volt panels in series is 8.33 amps. The higher voltage panels begin to output a voltage (suitable for charging your battery bank) sooner in the morning and later before sunset. As long as the solar controller is rated to handle the voltage output of the panels you’ll be ok.

solar controllers are usually rated by max input voltage like you said, but you have to use the open circuit voltage (VOC) of the panel, which on a 24V (nominal) panel is usually about 35 to 40V. so the 37.5 Volt panels you are talking about are 24V panels. confusing enough haha

[firestation12]

Originally Posted by Stircrazy

solar controllers are usually rated by max input voltage like you said, but you have to use the open circuit voltage (VOC) of the panel, which on a 24V (nominal) panel is usually about 35 to 40V. so the 37.5 Volt panels you are talking about are 24V panels. confusing enough haha

VOC is what I always refer to when researching panel output. My Renogy 60 solar controller reports the 2 solar panel volts in in series, in that voltage range (70ish). I’ll have to find a pic of my panel data, and see why I missed the 24 volt thing. Thx

[Stircrazy]

Originally Posted by firestation12

VOC is what I always refer to when researching panel output. My Renogy 60 solar controller reports the 2 solar panel volts in in series, in that voltage range (70ish). I’ll have to find a pic of my panel data, and see why I missed the 24 volt thing. Thx

ya the only time you actually see VOC is when there is no load and it's an open circuit. The only reason I even care about it is you can check to see the condition of a bare panel using it and you have to know what the voltage could go up to if a cable brakes or component fails.

[firestation12]

Originally Posted by Stircrazy

ya the only time you actually see VOC is when there is no load and it's an open circuit. The only reason I even care about it is you can check to see the condition of a bare panel using it and you have to know what the voltage could go up to if a cable brakes or component fails.

Here is the data for my 2 REC Panels. I checked the volts entering the solar controller today. It maxed at 69.6. This was considerably higher than the predicted 24 volts per panel. We’ve had rain the last 2 days. Today there was about 5 hours of sunshine. In any event the point of this thread was to assure the OP he would be fine using the 10 gauge pre-wire from the roof to the solar controller.

[Stircrazy]

Originally Posted by firestation12

Here is the data for my 2 REC Panels. I checked the volts entering the solar controller today. It maxed at 69.6. This was considerably higher than the predicted 24 volts per panel. We’ve had rain the last 2 days. Today there was about 5 hours of sunshine. In any event the point of this thread was to assure the OP he would be fine using the 10 gauge pre-wire from the roof to the solar controller.

yup, if you blow a fuse or a wire breaks you will see up to 80 if there in series which is why you have to make sure the controller can handle the combined VOC. Plus, the output is never exactly 24V, that's just the classification of the panel just like how a 12V panel will output 17+ V to the controller. So, the working voltage for a 24V solar panel is approximately 32V so I would say you're running normally, what you got could even be a little high and if it is like that all the time, I wouldn't be that concerned about it. if it were always that high or gets higher, I would look for a source of extra resistance somewhere in the line, but it's not a lot higher than I would expect so it could just be an error in the voltage reading or a wire that is close to being maxed out and a bit extra resistance...

[firestation12]

Originally Posted by Stircrazy

yup, if you blow a fuse or a wire breaks you will see up to 80 if there in series which is why you have to make sure the controller can handle the combined VOC. Plus, the output is never exactly 24V, that's just the classification of the panel just like how a 12V panel will output 17+ V to the controller. So, the working voltage for a 24V solar panel is approximately 32V so I would say you're running normally, what you got could even be a little high and if it is like that all the time, I wouldn't be that concerned about it. if it were always that high or gets higher, I would look for a source of extra resistance somewhere in the line, but it's not a lot higher than I would expect so it could just be an error in the voltage reading or a wire that is close to being maxed out and a bit extra resistance...

So I get why one would be concerned about the voltage output for a single panel being used to provide maintenance for a 12 volt battery, but I see no usefulness in labeling a 34.2 Vmp panel a 24 volt panel. When installing my system 2 years ago I was concerned with how much current the 10 gauge wire would be carrying with 2 panels in series. The Renogy 60 moot controller was rated to handle 800 watts @ 12 volts and a maximum of 140 volts (VOC). I could have installed a 3rd panel in the series had the roof been able to accommodate it. I found no data from Rec that stated their panel was a “24 volt” (see the data sheet provided in a previous post).The panel manufacturer has no idea for what volt battery or system configuration it will be used. In my case the 2 280ah 12 volt LiPo4 batteries in parallel installation planning, didn’t require knowing a “category of 24 volts”.

[Stircrazy]

Originally Posted by firestation12

So I get why one would be concerned about the voltage output for a single panel being used to provide maintenance for a 12 volt battery, but I see no usefulness in labeling a 34.2 Vmp panel a 24 volt panel. When installing my system 2 years ago I was concerned with how much current the 10 gauge wire would be carrying with 2 panels in series. The Renogy 60 moot controller was rated to handle 800 watts @ 12 volts and a maximum of 140 volts (VOC). I could have installed a 3rd panel in the series had the roof been able to accommodate it. I found no data from Rec that stated their panel was a “24 volt” (see the data sheet provided in a previous post).The panel manufacturer has no idea for what volt battery or system configuration it will be used. In my case the 2 280ah 12 volt LiPo4 batteries in parallel installation planning, didn’t require knowing a “category of 24 volts”.

ya it's just a category based off the working voltage. its above 12V panels but below 48 volt commercial panels. its kinda like mains power in the US and Canada, they both work but one is 110V and in Canada we are 120V but both are 60hertz so we don't have a compatibility issue. they had to come up with a way to classify panels to make part selection easier so take my renogy, it says it will take 12v or 24V panels, you have the 60 amp so it probably lists 48V also. but mine also lists the maximum voltage input as Max. PV Input Voltage:100 VDC so now depending on which panels I use the open circuit voltage of those panels will tell me how many I can install.
Your 60amp controller can take a Max. PV Input Voltage:140VDC. so, for me I can install a second panel on mine which would give me a little over 80Vdc potential input. or I could have found a smaller panel that was under 33 VOC and installed 3. With two I have 650watts of solar you could install 3 of my panels and have 975 watts and be under the 140VDC. It's just a way of grouping panel types to make the initial design selection easier. The only way you will hit that VOC is if you have a condition where the system is not acceting power from the panel ie. broken wire, failed controler, batteries turned off so it can charge and so on. working voltage will be a lot lower as now you have flow so maybe it is based on the average working voltage at the rated wattage.

[firestation12]

Originally Posted by Stircrazy

ya it's just a category based off the working voltage. its above 12V panels but below 48 volt commercial panels. its kinda like mains power in the US and Canada, they both work but one is 110V and in Canada we are 120V but both are 60hertz so we don't have a compatibility issue. they had to come up with a way to classify panels to make part selection easier so take my renogy, it says it will take 12v or 24V panels, you have the 60 amp so it probably lists 48V also. but mine also lists the maximum voltage input as Max. PV Input Voltage:100 VDC so now depending on which panels I use the open circuit voltage of those panels will tell me how many I can install.
Your 60amp controller can take a Max. PV Input Voltage:140VDC. so, for me I can install a second panel on mine which would give me a little over 80Vdc potential input. or I could have found a smaller panel that was under 33 VOC and installed 3. With two I have 650watts of solar you could install 3 of my panels and have 975 watts and be under the 140VDC. It's just a way of grouping panel types to make the initial design selection easier. The only way you will hit that VOC is if you have a condition where the system is not acceting power from the panel ie. broken wire, failed controler, batteries turned off so it can charge and so on. working voltage will be a lot lower as now you have flow so maybe it is based on the average working voltage at the rated wattage.

OK, this will be my last attempt to say there is no such thing as a “category 24v nominal panel” (your post #11, or “plus the output is never exactly 24 volt that’s just the classification” your post #15, or “ya it’s just a category based off the working voltage” your post #17. The information on the back of each panel is strictly controlled and nowhere will you find those terminologies posted on the panel manufacture’s website or on the back of a panel. You may find a search result on Amazon or eBay for “24 volt solar panel”, but that is nothing more than an attempt to help direct a buyer to a solar product. As for the 110 volt/120 volt comment of the difference in voltage in Canada versus the US, this is again just not true. The voltage standard is the same 120/240 volts (see the attachment) Canada supplies the northeast US with approx 35 feeds. The only difference is in some Canadian providences is motor voltage is provided at 600 volt three phase as opposed to 480 volt 3 phase used in the US. This is corrected by use of an onsite transformer that adjusts the power configuration desired by the facility receiving the electrical utility output. Canada has the same problem we have i.e. people still refer to their electricity as 110/220. Using the term “category 24 volt panels and 110/220 volts” may be what you like to use but it is not supported by fact. As the saying goes, “you have a right to your opinions but not to your facts”.

The rest of your quote leaves me dumbfounded. I have no idea what point you are trying to convey or how it is useful to the OP Drazul’s post #1.

[quote Your 60amp controller can take a Max. PV Input Voltage:140VDC. so, for me I can install a second panel on mine which would give me a little over 80Vdc potential input. or I could have found a smaller panel that was under 33 VOC and installed 3. With two I have 650watts of solar you could install 3 of my panels and have 975 watts and be under the 140VDC. It's just a way of grouping panel types to make the initial design selection easier. The only way you will hit that VOC is if you have a condition where the system is not acceting power from the panel ie. broken wire, failed controler, batteries turned off so it can charge and so on. working voltage will be a lot lower as now you have flow so maybe it is based on the average working voltage at the rated wattage.” End QUOTE]

Lastly your quote ” take my renogy, it says it will take 12v or 24V panels”. Perhaps you have a pic of that? Did you mean to say a Renogy solar controller’s OUTPUT may accommodate 12,24,36 or 48 volt battery configurations (depending on the controller model)? As stated earlier, solar panel manufacturers adhere to a strict standard of labeling. The information on the back of each solar panels conforms to that standard. No mention of a “24 voltage category” is found on any data sticker or data sheet. Panel selection starts with wattage, volts and amps. The rest is up to the installer to figure out. Please stop using “24 volt category”.

[Drazul]

Thank you all for the input. I have it all put together and installed. Planned for future expansion as well. Your comments were appreciated.

[snoobler]

Handy tool for putting panels on a Victron MPPT (don't be surprised if it allows for up to 30% over-paneling):

https://www.victronenergy.com/mppt-calculator

Rules for over-paneling:

https://www.victronenergy.com/blog/2...ge-regulators/

Short version: Never exceed MPPT rated voltage allowing suitable margin for cold temps and never exceed the PV input current limit.