Wow, great video. We have a setup similar to Configuration 7. Though I have had zero issues with it, this last weekend I was at a campsite that was well shaded. Our 3@100watt panels (connected in series mounted on the roof) was just not powerful enough to charge the 200Ah Renogy battery fully. So I was thinking that in cases where we are in shade, can I add a portable solar panel? How would I charge the battery? Could I somehow plug the solar panel with its own controller into a cigarette lighter (that is powered by the RV battery), or possibly connect the portable panel (with controller) directly to the RV battery? So we'd have two ways that the battery is being charged.... We have a 20A Renogy MPPT controller, 3@100 watt panels connected in series to a 200Ah Renogy 12V battery. One possibility: Can I add a 20A PWM controller with a 200 watt portable solar panel directly to the battery with alligator clips?
Great job on the videos! I wish I saw these videos before I bought my 200 watt Renogy suitcase panels. Question - I have a factory installed furrion solar charging port on the side of my trailer with a 10 apm fuse. Your comment it is limited to 10 amps, Can I change out the fuse to 15 or 20 amps? so I can use this port? or should I set up a charging port on the side of the battery case. Any inpot you can give would be great.
Excellent Solar tutorials! I have a question as well. I have a factory installed rooftop 190 watt setup with it's own 30amp PWM Controller inside the camper, and I would like to use my 200w Suitcase setup with 20amp MPPT Controller on the outside. I know the Suitcase setup will attach to my Zamp plug, but the concern I have is will one controller override, or cancel out the other, and will there be any conflicts. OR will both controllers just work indepently, in harmony, to keep the battery charged. Thanks in advance for your time.
Just stumbled across this, thanks for the helpful info. I will have a 100w roof mount and 2 100 w portable panels with a Renogy 40A MPPT. Can I wire them in series and then enter the contoller and not blow myself up? Sorry, new to all this and trying to do it right. Thanks again.
I always have to put out a disclaimer that refer any electrical work to a qualified person if you are not skilled. Not sure if your comment was humor, but I will take it as such. Yes, with a NPPT controller you can put panels in series. However, when you do so, the voltage increases for each panel. For example, most panels have a 20v characteristic voltage. Wiring those two panels in parallel will still result in 20V (although the current will be doubled). Wiring them in series will result in 40V (while the current stays the same). So, when wiring two panels in series, you double the voltage and the current is unchanged. Wiring the panels in parallel doubles the current and the voltage stays the same. And the same thing happens with 3 panels. In series, the panel voltage is 3x, and in parallel the current is 3x. One of the main benefits of wiring the panels in series is it is more efficient for the current flowing from the panels to the controller from a voltage drop perspective. One thing you must determine is if the MPPT controller can handle the increased voltage you will apply to it by putting the panels in series.
Excellent. I have a question. Let's say that you have 150 watts on your RV roof and an RV built-in MPPT charge controller that is 30amp. You know that the roof panel's VMP is 18 volts, IMP is 8.38 amps and well below the charge controller max. You buy two Renogy 100 watt suitcases that share the VMP of 18 volts and have IMP of 2.78x2 or 5.56 amps. You have a Zamp plug on the exterior of your RV that goes to the controller and connection shared with the roof panel. Would you just combine the suitcases' positive and negative leads to make a parallel circuit then to the Zamp? I know that my controller is 30 amp so this is my thought but what do you think?
I have a 2016 Rockwood 2304DS TT with a prewired Zamp sae type connector. Do I need a controller between the battery and solar panel for a 100w or 200w panel? I don’t know if a controller is already installed.
I'm in the process of working with Renogy now to upgrade my system. I have my tag along camper at an off grid site. I use an inverter generator when I'm there on the weekends. My camper is a 2020 with a 12v only fridge that we keep running all week. I have 2 6v golf cart batteires wired in series on the tongue of the camper. I've been using a 200w Renogy suitcase but it just doesn't put out enough to charge the batteries while we aren't there. It slows the discharge down but still doesn't provide enough to charge. I'm thinking to upgrade to 400w total. They told me to get a 40a MPPT charger but then I have to do entry and exit wiring connections to the camper wall which I'd rather not unless I HAVE to. I don't want water issues. I'm wondering if I can simply get another 200w suitcase setup with the 20a controller they come with and wire both setups in parallel to the battery terminals on the tongue. I'm waiting for their support to get back to me on that. I have read that both controllers will not fight one another and it will be fine. Thoughts?
If you have a suitcase, I am assuming you are using it on the ground. You should be able to add another suitcase to your array. You can wire it in either serial or parallel, but to provide maximum energy transfer, serial is a better connection. Serial connection requires a MPPT controller. Renogy should be able to help you with that.
@@RVProject yes I do have it on the ground. I was hoping I could just use another one and have the 2 controllers not fight one another. I was hoping to now have to use a new controller because I wasn't thrilled about making holes in the rv wall for the wiring. The batteries are on the tongue and the controller would have to go inside. So id need a few sets of holes. I'd rather not have to do that.
@@patrickm6000 If you already have a MPPT controller, all you have to do for the second panel is to wire it to the first panel. No need to run wires back to the controller. Refer to part 5 of my solar panel series: www.rv-project.com/projects/suitcase4.php ruclips.net/video/0Ufm9HHGdQs/видео.html
@@patrickm6000 Are there MC4 connectors on the solar side of the charge controller? If so, that is where you would make the serial connection. I would advise against paralleling two controllers. The proper way would be to put the panels in parallel or serial before connection to the controller.
Did your RV have a charge controller already wired into the "solar ready plug"? Or did you connect the panels to a newly purchased controller and the battery end of the controller to the RV solar plug you rewired?
Great video. I will head over and start studying your webpage closer. In the meantime, I’m in the planning stages of a setup for my travel trailer and looking to connect two 100w, 12v panels in series which makes it 24v through mc4 connectors and 10awg cable to the trailer’s SAE input, into a 100/15 MPPT controller and then to the 12v battery. I’m feeling stumped or maybe just overthinking it. Even though it’s 24v going into the controller, the controller will “control” that down to 12v to safely charge my 12v (or 2x 6v batteries in series? Am I missing something? It also confuses me that the panels are listed as 12v but the specs say optimum operating voltage of 18.5v and open circuit voltage of 22.6v. As you can probably tell, I’m still in the research/learning phase.
The panels will put out about 18V or so when connected to a charge controller. The open circuit voltage is when they are not connected to anything, which means they are not under load. So in series, you essentially have 18V x 2 = 36V for the solar panels. In this configuration, you need a MPPT controller. This controller can take that excess voltage (above the 12-14V required by the battery) and convert it into additional charge current. The side benefit of this is not only increased efficiency, but you can extend the solar panels further as the voltage drop issue is not as bad as with the panels wired in parallel with a PWM controller. Therefore, the primary reason to put panels in series is to reduce voltage drop issues, and allow smaller AWG wiring to be used. Again, this can only be done with a MPPT controller. A PWM controller cannot convert excess voltage to current. It must dissipate any excess voltage so placing 36V on the input would likely overheat and fry the controller. It is simply not designed to dissipate that much energy. Regardless of the charge controller used, the output to the battery will be dropped down to about 12.9V to 14.4V depending on the charger state. The higher the voltage on the battery, the faster it will charge. 14.4V will charge the battery faster, but it can damage the battery when it goes into overcharge. For that reason, the charger drops down to 12.9V (trickle charge), which keeps the battery topped off. A fully charged battery is about 12.6V. Whenever a higher voltage is applied to the battery, it will charge. Thus the reason for the charge controller output of 12.9 to 14.4V Since there are a few inefficiencies involved, a PWM charger needs around 2V overhead to work properly - which means about 16V to 20V on it's input (where the solar panel is connected) to produce the required 14.4V for the fast-charge mode. If the solar voltage drops below 16V, then the output of the charge controller can never be as high as 14.4V, due to the 2V overhead it needs. So the result is the charger can never charge as fast as it could. The primary reason for the loss in input voltage is again, the distance of the extension cable to the solar panels. Back to the MPPT controller, it also needs a bit of an overhead - the same 16V. But remember, the voltage is 36V, so the voltage loss in the extension cable will never affect the ability of the MPPT controller to output 14.4V on the battery. And with it's ability to convert voltage into current, it gains more efficiency vs. the PWM charger. IF you watch the other videos, you should figure it out. Thanks for your support.
@@RVProject wow. Seriously wow. The way you explain things is so clear and concise. I am rally looking forward to watching the entire series. Subscribed and liked!
Thanks for making and sharing this video. Two quick questions on configurations 5 and 7. 1) What size of a fuse should you use between the controller and the battery? 2) Will using 10AWG vs 12AWG be of much benefit for the extension cable? Thanks again for your efforts here.
The fuse should be sized for the maximum charge current the panels are capable of. Fuses are rated for the maximum current it will allow to pass - not at which point it will blow. See my video "All about fuses": ruclips.net/video/tUomOpNUjHE/видео.html In video 3 of my suitcase solar panel playlist, I cover the reasons why 10AWG wire should be used: ruclips.net/video/A6PxSvuGc5U/видео.html Finally, here is the suitcase solar panel playlist: ruclips.net/p/PL9L2lLziJeInW0EznBZhIYsnG1tQlHTOJ
Excellent video on fuses, thanks for the education. So, a 7.-5 to 10a should be used? Any thoughts on question #2 in benefits using 10AWG vs 12 AWG for the extension cable?
@@TheCabinman Watch video 3: ruclips.net/video/A6PxSvuGc5U/видео.html Say you have a 100Watt Suitcase Solar panel. It will produce 5.5A peak at 18V or so. If you have a PWM controller, it will convert that voltage to 12.9~14.4V or so to charge the battery. A 3 stage (Smart) charger will output 14.4V for Fast charging. 13.5V for Normal (or Absorption) charging, and 12.9V for Trickle charging. If you apply a smart charger to a battery that is less than 80% charged, it will start off with fast charging to bring it up to 80%. Then it will go into Normal mode to bring it up to 100%. And finally, it will go into overcharge with a Trickle charge. The Trickle charge is designed to keep the battery topped off without damaging or gassing the battery. So essentially, the charger varies the voltage on the battery to go into the different charge states. But no charger is 100% efficient. Even though the maximum voltage at the charger output is around 14.4V, it takes around 16V on it's input to produce that voltage. The solar panel output is 18V, so the minimum input voltage to the charger to produce a 14.4V rapid charge is 16V. Therefore, we have a 2V margin between the solar panel and charger for proper operation. Anytime current flows through a wire, it is an electro-mechanical process, and causes friction. The more friction, the more voltage required to push the electrons through the wire. This essentially reduces the voltage at the end of the wire. In other words, the wire more-or-less absorbs some voltage. The amount of voltage loss is dependent on the wire size, length of wire, and amount of current flowing through the wire. There are Voltage Drop calculators on the internet, and I have one on my website as well ( www.rv-project.com/tips/wirecalc.php ). It does all the math for you, and all you need to do is input wire size, distance and current. Lets say you want to add 20ft of extension from the RV to the solar panel. And lets also assume the charge controller is located at the solar panel. From the voltage drop calculator, the following voltage drops will occur when the maximum 5.5A current from the solar panel is applied to the charger: 14AWG = 0.577V 12AWG = 0.364V 10AWG = 0.225V When the charger goes into rapid (Bulk) charge, and applies 14.4V to the battery, by the time it reaches the battery, the voltage will be: 14AWG = 13.52V 12AWG = 14.03V 10AWG = 14.17V In all of these situations, the ability of the battery to be rapidly charged will be diminished. In fact, with 14AWG wire, the charger is in Bulk mode, but the voltage at the battery is at the Normal mode level. Even at 10AWG, there is some loss in charger efficiency - but at least it's manageable. You paid for 100Watts of charge power from your solar panel, but some of it is absorbed by the wiring, and you will never get that 100Watts to the battery. What confuses people is that an Ampacity chart will show that a 14AWG wire can handle 15A, 12AWG - 20A, and 10AWG - 30A, so they figure they can use 14AWG wire given the current load is 5.5A maximum. But they fail to realize there is an associated voltage drop. You have to use the larger wire NOT because of the current carrying capability, you need the larger wire due to the voltage drop. This is the major issue with locating the charge controller next to the solar panel. For this reason, I highly recommend relocating the charge controller to the RV, as close as possible to the battery. When you do that, the voltage drop in the wiring is between the solar panel and charger, not between the charger and battery. And I have shown that you have a 2V margin between the charger and solar panel. So, in this situation, you could use up to 50ft of 14AWG wire for an extension - which would drop the voltage by 1.5V. But since this is at the input of the charger - not the battery, it is still higher than the required voltage of the charger, you have no voltage loss at the battery in bulk charge mode. I do discuss this in my video series - check out the playlist. So to recap. My recommendation is that if the charger is located on the solar panel, you should minimize the extension cord to 20ft using 10AWG wire - and even then, you will have some loss of charge voltage in bulk charge. But if you locate the charge controller at the battery, you can use 50ft of 14AWG wire for an extension and have no loss in charger performance in bulk charging.
Thank you so much for the detailed response. I do plan on locating the Victron 75/15 near the battery and will use 12AWG or 14AWG for the extension wire (50ft). To your point, the voltage from the Victron to the battery (in my case Battleborn LiFePO4 battery) will be charging at 14.4v, so the fuse there should be 20v between the controller and the battery, correct? Thanks again for taking the time to share you knowledge.
My head is spinning with scenarios but I still don’t see the one I want so I’ll ask the question. I have a 200w Renogy suitcase panel. If I moved the 20a PWM controller over to the battery(200wh AGM), how long of a 10awg extension could I use? Thanks in advance.
Im subscribing ...can you show us how to connect a folding solar panel which has a charging box not charge controller (?? But i know the battery needs charge controller i think??) to a deep cycle battery to charge it??? ...minivan camper......Im.looking for a video that does this but cant find it ....you seem SUPER knowledgeable and im kinda begging for myself. ....a newbie Goal for me is to use a deep cycle 100 aH and a charge controller and folding 100 or 120 watt panel ...but all those panels come with a charging box??? Not charge controller...i need to learn how to connect all those and then alligator clip to the battery i think?? ....can you help ?
I am not sure what a "charging box" is. Every portable suitcase I have seen more than 50AH includes a charge controller. A charge controller takes the 18VDC (or more) from the solar panel and runs it through a battery charging circuit to the battery. There are some small solar panels that have a charging mechanism built into the panel, but even those are charge controllers. Can you elaborate a bit more on what you have?
Great series. Thx! Question please. I am currently using Config 5 with my Renogy 100w briefcase on my camper. I was thinking about going to Config 7 which is why I found your videos. I think you are saying that if I add a panel I must switch out the PWM controller for a MPPT? Is that correct? And why if don't mind. Thx again? Scott
It might be helpful to review my video on the differences between PWM and MPPT controllers: ruclips.net/video/EjCUR9jFphc/видео.html In configuration 7, a second solar panel is added in series with the first one. This results in the voltage on the solar input terminals of the PWM controller to be 36V. It cannot handle this voltage, and it's a waste of a panel. The PWM controller cannot convert one voltage to another, but it simply discards the additional voltage as heat. So it would have to discard 36V (solar panel voltage) - 14V (battery charge voltage)... or 22V. 22V@5.5A = 121 Watts. This excess energy would burn up the controller. So when you add a second panel in series to a PWM controller, you increase the voltage which requires the controller to get rid of, but you see no improvement in charger performance. A MPPT controller can convert a higher voltage to a lower voltage, so it converts 36V @ 5.5A from the solar panel to 14V @ 13A at the battery. While you could wire the second panel in parallel with the existing panel and use your existing PWM controller, you are again wasting energy because the series resistance in the wiring will start to become an issue. You would likely have to increase the AWG of the wiring to obtain the best performance in this situation. A high quality Victron 75/15 controller is about $100, so it is not a really costly item. In fact, compared to wiring the two panels in parallel, the cost new heavy duty wire would offset much of the cost of the MPPT controller. And a MPPT controller is also about 10% more efficient than a PWM controller. Also, if you are going to add new panels, especially in series, I highly recommend buying the same brand, model, and specification panel.
Another really good video, love these, you said something that got me worried though, (some rv manufacturers dont actually plug the furrion port to the battery, therefore you have to do that yourself). 2 months ago, i purchased a forest river salem fsx, actual model is the 178bhsk. Anyhow, one of the things i liked so much about it was the furrion port, being, solar ready...Was your Grand Design furrion port already plugged to the battery? I hope my forrest river is...
I just looked back at one of the videos, noticed your furrion port wasnt already plugged to the battery...Is that complicating to do? Can you make a video showing how to do that?
I think it's typical that the RV companies don't connect the port of the battery. But it is simple to do, Red wire from the solar port to the battery positive, black wire to battery negative.
@@49ers49ers Grand Design ships their units without a battery, and as part of the sale, the dealer typically installs the battery, so it's up to them whether or not the Furrion port is connected. The dealer did not connect the port when I bought my Grand Design 29RS, and feedback from many other owners of GD and other brand RV, it appears that dealers typically leave the port disconnected. I would suggest looking in the battery compartment and see if it looks like there is a set of mystery wires not connected to anything. Or, using a multimeter (voltage scale) measure the pins on the Furrion connector. If connected, it will read the battery voltage.
I'm surely missing something so my apologies but referencing configuration 8, why is the upgraded MPPT controller needed if 11amps are coming in and it's rated for 15amps?
Because the two panels are wired in series, which results in almost 40VDC input to the controller. Only a MPPT controller can handle this higher voltage, and in effect, it converts the higher voltage into additional current. A PWM controller can only handle around 18VDC or so coming from the solar panels. The excess voltage would need to be dissipated by the controller, which it is really not designed to do, and would likely overheat and eventually damage the PWM controller. To look at it another way: MPPT controller connected to two 200W solar panels in series will provide 14.4VDC @ 22 to 26Watts (the MPPT controller is efficient at converting voltage to current). PWM controller connect to two 200W solar panels in series will provide 14.4VDC @ 11Watts - with 11Watts needing to be dissipated. So you are really wasting money on the second panel as all of it's energy is being converted to waste heat. So in reality, when connecting these panels in series, you must use a MPPT controller as a PWM controller cannot handle the higher input voltage. Of course, you could connect the panels in parallel with a PWM controller, but then you are going to have some voltage loss in the extension wire, and loss of conversion efficiency. Comparing the two; the MPPT controller will be something like 93% efficient, while the PWM controller might only be around 75% efficient, depending on the AWG and length of extension cable from the controller to the panels. I do explain the differences between PWM and MPPT and series vs. parallel in my suitcase video series: www.rv-project.com/projects/suitcase.php
@@RVProject I understand the need for an MPPT vs. PWM, but for example I'm running a Victron MPPT 100/15 and thought I could upgrade my 200w system later to 400w (configured like your #8) and because my voltage would be coming in at 36v and amperage at 11amps I would not need to upgrade the MPPT controller but it appears the output amperage from the MPPT controller to the battery is too high, thus requiring the updated MPPT controller?
@@joshhaas2410 The Victron part number scheme is a bit confusing, but: MPPT Input Voltage/Output Current So MPPT 75/15 can handle up to 75V input, but can only deliver 15A output. MPPT 100/30 has a 100V input capability, and 30A output capability. Since you can potentially see up to 26A on the output current of the controller with two 200W solar panels, a 15A controller won't work.
@@RVProject Thank you, that explains it. I wish I had read the specs closer when I originally purchased the controller as I thought I was good for the upgrade but should not have assumed 15amp was only pointing to the input side when it's both input and output. Darn.
I can't figure this out :( - I hope someone can help me. I have a 100W Jackery solar panel - How do I connect it to my Winnebago Micro Mini camper? Do I need an 8mm to MC4 connector? Please help!
I loved the series! Thank you so much for putting this together. May I get clarification on Configuration 8? You upgraded the MPPT controller to 100/30 to accommodate the potential for 26 amps of charge current. Is this just in case the panels are hooked up in parallel? If hooked up in series (as shown in the diagram), wouldn't it stay at 11 amps and still be within specs of the original MPPT controller?
My setup has turned out pretty awesome however I’m noticing my 2x 100w panels in series are very picky with the sun and any tiny amount of shading seriously degrades the output given the 2 panels are in series. Like from 175w down to 30w. Wow! It’s left me wondering; even though I’ve gained in the area of very little voltage line loss what are your thoughts on switching to parallel, having a bit of line loss and not having shade on one cell completely screwing the output of both, being they’re wired as a string?
Make sure you have bypass diodes installed in your setup. These diodes are critical when wiring the panels in series as they prevent the exact issue you are describing.
Are you concerned with someone walking away with your solar panels? I want to use them, but usually go hiking during daytime and am concerned with someone possibly walking away with them from the campsite if I am not there. Any thoughts?
If we are going to be absent any length of time we put our solar suitcase on the roof, lean an unfurled patio umbrella against the cords to somewhat disguise them to a casual glance and block the ladder access.
Can you charge and discharge at the same time. If we are using a battery bank and charging that from solar, is there any reason why I can't use the power from the battery bank at the same time I am charging that battery bank.
Yes. If you connect a solar panel to your RV battery while it is in use, then you are both charging and discharging at the same time. This is the typical method of operation.
@@RVProject Now that wouldn't work on a solar generator would it ?, or is that still the same? I know you can obviously charge a solar generator from a solar panel, that's one of the ways of recharging, but I've never really heard anyone say anything about being able to discharge at the same time your charging on a solar generator.
The creator of these amazing videos passed away in June 2022
😢
🙏
Oh no! That is terrible!!!! I just fund him and have been watching them all. What a shame. So sad to hear this.
I watched many many of this kind of videos and this one so far has been the best, Thank you.
Thank you for your kind words.
Love your videos. Thank you!
Really good information here, instead of saying awg you could just say gauge and we will all know what you’re talking about. 8 gauge, 10 gauge etc..
Great video, thank you!
Glad you liked it!
Wow, great video. We have a setup similar to Configuration 7. Though I have had zero issues with it, this last weekend I was at a campsite that was well shaded. Our 3@100watt panels (connected in series mounted on the roof) was just not powerful enough to charge the 200Ah Renogy battery fully. So I was thinking that in cases where we are in shade, can I add a portable solar panel? How would I charge the battery? Could I somehow plug the solar panel with its own controller into a cigarette lighter (that is powered by the RV battery), or possibly connect the portable panel (with controller) directly to the RV battery? So we'd have two ways that the battery is being charged.... We have a 20A Renogy MPPT controller, 3@100 watt panels connected in series to a 200Ah Renogy 12V battery. One possibility: Can I add a 20A PWM controller with a 200 watt portable solar panel directly to the battery with alligator clips?
Great job on the videos! I wish I saw these videos before I bought my 200 watt Renogy suitcase panels. Question - I have a factory installed furrion solar charging port on the side of my trailer with a 10 apm fuse. Your comment it is limited to 10 amps, Can I change out the fuse to 15 or 20 amps? so I can use this port? or should I set up a charging port on the side of the battery case. Any inpot you can give would be great.
Excellent Solar tutorials! I have a question as well. I have a factory installed rooftop 190 watt setup with it's own 30amp PWM Controller inside the camper, and I would like to use my 200w Suitcase setup with 20amp MPPT Controller on the outside. I know the Suitcase setup will attach to my Zamp plug, but the concern I have is will one controller override, or cancel out the other, and will there be any conflicts. OR will both controllers just work indepently, in harmony, to keep the battery charged. Thanks in advance for your time.
Good day, I have the same question. Did you figure this one out?
The creator of these amazing videos passed away in June 2022. So he won't be answering your question.
@@campusa8742 How sad, and what a loss!
Just stumbled across this, thanks for the helpful info. I will have a 100w roof mount and 2 100 w portable panels with a Renogy 40A MPPT. Can I wire them in series and then enter the contoller and not blow myself up? Sorry, new to all this and trying to do it right. Thanks again.
I always have to put out a disclaimer that refer any electrical work to a qualified person if you are not skilled. Not sure if your comment was humor, but I will take it as such.
Yes, with a NPPT controller you can put panels in series. However, when you do so, the voltage increases for each panel.
For example, most panels have a 20v characteristic voltage. Wiring those two panels in parallel will still result in 20V (although the current will be doubled). Wiring them in series will result in 40V (while the current stays the same).
So, when wiring two panels in series, you double the voltage and the current is unchanged. Wiring the panels in parallel doubles the current and the voltage stays the same.
And the same thing happens with 3 panels. In series, the panel voltage is 3x, and in parallel the current is 3x.
One of the main benefits of wiring the panels in series is it is more efficient for the current flowing from the panels to the controller from a voltage drop perspective.
One thing you must determine is if the MPPT controller can handle the increased voltage you will apply to it by putting the panels in series.
@@RVProject Thank you, appreciate your help!
Excellent. I have a question. Let's say that you have 150 watts on your RV roof and an RV built-in MPPT charge controller that is 30amp. You know that the roof panel's VMP is 18 volts, IMP is 8.38 amps and well below the charge controller max. You buy two Renogy 100 watt suitcases that share the VMP of 18 volts and have IMP of 2.78x2 or 5.56 amps. You have a Zamp plug on the exterior of your RV that goes to the controller and connection shared with the roof panel. Would you just combine the suitcases' positive and negative leads to make a parallel circuit then to the Zamp? I know that my controller is 30 amp so this is my thought but what do you think?
The creator of these amazing videos passed away in June 2022.
I have a 2016 Rockwood 2304DS TT with a prewired Zamp sae type connector. Do I need a controller between the battery and solar panel for a 100w or 200w panel? I don’t know if a controller is already installed.
I'm in the process of working with Renogy now to upgrade my system. I have my tag along camper at an off grid site. I use an inverter generator when I'm there on the weekends. My camper is a 2020 with a 12v only fridge that we keep running all week. I have 2 6v golf cart batteires wired in series on the tongue of the camper. I've been using a 200w Renogy suitcase but it just doesn't put out enough to charge the batteries while we aren't there. It slows the discharge down but still doesn't provide enough to charge. I'm thinking to upgrade to 400w total. They told me to get a 40a MPPT charger but then I have to do entry and exit wiring connections to the camper wall which I'd rather not unless I HAVE to. I don't want water issues. I'm wondering if I can simply get another 200w suitcase setup with the 20a controller they come with and wire both setups in parallel to the battery terminals on the tongue. I'm waiting for their support to get back to me on that. I have read that both controllers will not fight one another and it will be fine.
Thoughts?
If you have a suitcase, I am assuming you are using it on the ground. You should be able to add another suitcase to your array. You can wire it in either serial or parallel, but to provide maximum energy transfer, serial is a better connection.
Serial connection requires a MPPT controller.
Renogy should be able to help you with that.
@@RVProject yes I do have it on the ground. I was hoping I could just use another one and have the 2 controllers not fight one another. I was hoping to now have to use a new controller because I wasn't thrilled about making holes in the rv wall for the wiring. The batteries are on the tongue and the controller would have to go inside. So id need a few sets of holes. I'd rather not have to do that.
@@patrickm6000 If you already have a MPPT controller, all you have to do for the second panel is to wire it to the first panel. No need to run wires back to the controller.
Refer to part 5 of my solar panel series:
www.rv-project.com/projects/suitcase4.php
ruclips.net/video/0Ufm9HHGdQs/видео.html
@@RVProject no sir. Currently all I have is the factory suitcase with the voyager 20a controller. I'm planning the rest of it now.
@@patrickm6000 Are there MC4 connectors on the solar side of the charge controller? If so, that is where you would make the serial connection.
I would advise against paralleling two controllers. The proper way would be to put the panels in parallel or serial before connection to the controller.
Did your RV have a charge controller already wired into the "solar ready plug"? Or did you connect the panels to a newly purchased controller and the battery end of the controller to the RV solar plug you rewired?
The creator of these amazing videos passed away in June 2022.
@@campusa8742 very sorry to hear that, glad his legacy lives on
Great video. I will head over and start studying your webpage closer. In the meantime, I’m in the planning stages of a setup for my travel trailer and looking to connect two 100w, 12v panels in series which makes it 24v through mc4 connectors and 10awg cable to the trailer’s SAE input, into a 100/15 MPPT controller and then to the 12v battery. I’m feeling stumped or maybe just overthinking it. Even though it’s 24v going into the controller, the controller will “control” that down to 12v to safely charge my 12v (or 2x 6v batteries in series? Am I missing something? It also confuses me that the panels are listed as 12v but the specs say optimum operating voltage of 18.5v and open circuit voltage of 22.6v. As you can probably tell, I’m still in the research/learning phase.
The panels will put out about 18V or so when connected to a charge controller. The open circuit voltage is when they are not connected to anything, which means they are not under load.
So in series, you essentially have 18V x 2 = 36V for the solar panels.
In this configuration, you need a MPPT controller. This controller can take that excess voltage (above the 12-14V required by the battery) and convert it into additional charge current.
The side benefit of this is not only increased efficiency, but you can extend the solar panels further as the voltage drop issue is not as bad as with the panels wired in parallel with a PWM controller.
Therefore, the primary reason to put panels in series is to reduce voltage drop issues, and allow smaller AWG wiring to be used. Again, this can only be done with a MPPT controller.
A PWM controller cannot convert excess voltage to current. It must dissipate any excess voltage so placing 36V on the input would likely overheat and fry the controller. It is simply not designed to dissipate that much energy.
Regardless of the charge controller used, the output to the battery will be dropped down to about 12.9V to 14.4V depending on the charger state. The higher the voltage on the battery, the faster it will charge. 14.4V will charge the battery faster, but it can damage the battery when it goes into overcharge. For that reason, the charger drops down to 12.9V (trickle charge), which keeps the battery topped off.
A fully charged battery is about 12.6V. Whenever a higher voltage is applied to the battery, it will charge. Thus the reason for the charge controller output of 12.9 to 14.4V
Since there are a few inefficiencies involved, a PWM charger needs around 2V overhead to work properly - which means about 16V to 20V on it's input (where the solar panel is connected) to produce the required 14.4V for the fast-charge mode.
If the solar voltage drops below 16V, then the output of the charge controller can never be as high as 14.4V, due to the 2V overhead it needs. So the result is the charger can never charge as fast as it could. The primary reason for the loss in input voltage is again, the distance of the extension cable to the solar panels.
Back to the MPPT controller, it also needs a bit of an overhead - the same 16V. But remember, the voltage is 36V, so the voltage loss in the extension cable will never affect the ability of the MPPT controller to output 14.4V on the battery. And with it's ability to convert voltage into current, it gains more efficiency vs. the PWM charger.
IF you watch the other videos, you should figure it out. Thanks for your support.
@@RVProject wow. Seriously wow. The way you explain things is so clear and concise. I am rally looking forward to watching the entire series. Subscribed and liked!
Thanks for making and sharing this video. Two quick questions on configurations 5 and 7. 1) What size of a fuse should you use between the controller and the battery? 2) Will using 10AWG vs 12AWG be of much benefit for the extension cable? Thanks again for your efforts here.
The fuse should be sized for the maximum charge current the panels are capable of. Fuses are rated for the maximum current it will allow to pass - not at which point it will blow. See my video "All about fuses": ruclips.net/video/tUomOpNUjHE/видео.html
In video 3 of my suitcase solar panel playlist, I cover the reasons why 10AWG wire should be used: ruclips.net/video/A6PxSvuGc5U/видео.html
Finally, here is the suitcase solar panel playlist: ruclips.net/p/PL9L2lLziJeInW0EznBZhIYsnG1tQlHTOJ
Excellent video on fuses, thanks for the education. So, a 7.-5 to 10a should be used? Any thoughts on question #2 in benefits using 10AWG vs 12 AWG for the extension cable?
@@TheCabinman Watch video 3: ruclips.net/video/A6PxSvuGc5U/видео.html
Say you have a 100Watt Suitcase Solar panel. It will produce 5.5A peak at 18V or so. If you have a PWM controller, it will convert that voltage to 12.9~14.4V or so to charge the battery.
A 3 stage (Smart) charger will output 14.4V for Fast charging. 13.5V for Normal (or Absorption) charging, and 12.9V for Trickle charging.
If you apply a smart charger to a battery that is less than 80% charged, it will start off with fast charging to bring it up to 80%. Then it will go into Normal mode to bring it up to 100%. And finally, it will go into overcharge with a Trickle charge.
The Trickle charge is designed to keep the battery topped off without damaging or gassing the battery.
So essentially, the charger varies the voltage on the battery to go into the different charge states.
But no charger is 100% efficient. Even though the maximum voltage at the charger output is around 14.4V, it takes around 16V on it's input to produce that voltage. The solar panel output is 18V, so the minimum input voltage to the charger to produce a 14.4V rapid charge is 16V. Therefore, we have a 2V margin between the solar panel and charger for proper operation.
Anytime current flows through a wire, it is an electro-mechanical process, and causes friction. The more friction, the more voltage required to push the electrons through the wire.
This essentially reduces the voltage at the end of the wire. In other words, the wire more-or-less absorbs some voltage.
The amount of voltage loss is dependent on the wire size, length of wire, and amount of current flowing through the wire.
There are Voltage Drop calculators on the internet, and I have one on my website as well ( www.rv-project.com/tips/wirecalc.php ). It does all the math for you, and all you need to do is input wire size, distance and current.
Lets say you want to add 20ft of extension from the RV to the solar panel. And lets also assume the charge controller is located at the solar panel.
From the voltage drop calculator, the following voltage drops will occur when the maximum 5.5A current from the solar panel is applied to the charger:
14AWG = 0.577V
12AWG = 0.364V
10AWG = 0.225V
When the charger goes into rapid (Bulk) charge, and applies 14.4V to the battery, by the time it reaches the battery, the voltage will be:
14AWG = 13.52V
12AWG = 14.03V
10AWG = 14.17V
In all of these situations, the ability of the battery to be rapidly charged will be diminished. In fact, with 14AWG wire, the charger is in Bulk mode, but the voltage at the battery is at the Normal mode level.
Even at 10AWG, there is some loss in charger efficiency - but at least it's manageable. You paid for 100Watts of charge power from your solar panel, but some of it is absorbed by the wiring, and you will never get that 100Watts to the battery.
What confuses people is that an Ampacity chart will show that a 14AWG wire can handle 15A, 12AWG - 20A, and 10AWG - 30A, so they figure they can use 14AWG wire given the current load is 5.5A maximum. But they fail to realize there is an associated voltage drop. You have to use the larger wire NOT because of the current carrying capability, you need the larger wire due to the voltage drop.
This is the major issue with locating the charge controller next to the solar panel. For this reason, I highly recommend relocating the charge controller to the RV, as close as possible to the battery.
When you do that, the voltage drop in the wiring is between the solar panel and charger, not between the charger and battery. And I have shown that you have a 2V margin between the charger and solar panel.
So, in this situation, you could use up to 50ft of 14AWG wire for an extension - which would drop the voltage by 1.5V. But since this is at the input of the charger - not the battery, it is still higher than the required voltage of the charger, you have no voltage loss at the battery in bulk charge mode. I do discuss this in my video series - check out the playlist.
So to recap. My recommendation is that if the charger is located on the solar panel, you should minimize the extension cord to 20ft using 10AWG wire - and even then, you will have some loss of charge voltage in bulk charge. But if you locate the charge controller at the battery, you can use 50ft of 14AWG wire for an extension and have no loss in charger performance in bulk charging.
Thank you so much for the detailed response. I do plan on locating the Victron 75/15 near the battery and will use 12AWG or 14AWG for the extension wire (50ft). To your point, the voltage from the Victron to the battery (in my case Battleborn LiFePO4 battery) will be charging at 14.4v, so the fuse there should be 20v between the controller and the battery, correct? Thanks again for taking the time to share you knowledge.
@@TheCabinman The max output of the Victron 75/15 is 15A, so either 15A or 20A fuse would work, depending on wire size from the charger to battery.
My head is spinning with scenarios but I still don’t see the one I want so I’ll ask the question. I have a 200w Renogy suitcase panel. If I moved the 20a PWM controller over to the battery(200wh AGM), how long of a 10awg extension could I use? Thanks in advance.
The creator of these amazing videos passed away in June 2022
I used a female 7 pin connector for my 100 W suitcase solar panel, I just plug it in to the 7 pin connector of the trailer.
That will work. I produced a video on how to make such a connector.
I love all your content, but I do not care for your website. I cannot find the project notes or photos.
Im subscribing ...can you show us how to connect a folding solar panel which has a charging box not charge controller (?? But i know the battery needs charge controller i think??) to a deep cycle battery to charge it??? ...minivan camper......Im.looking for a video that does this but cant find it ....you seem SUPER knowledgeable and im kinda begging for myself. ....a newbie
Goal for me is to use a deep cycle 100 aH and a charge controller and folding 100 or 120 watt panel ...but all those panels come with a charging box??? Not charge controller...i need to learn how to connect all those and then alligator clip to the battery i think?? ....can you help ?
I am not sure what a "charging box" is. Every portable suitcase I have seen more than 50AH includes a charge controller. A charge controller takes the 18VDC (or more) from the solar panel and runs it through a battery charging circuit to the battery.
There are some small solar panels that have a charging mechanism built into the panel, but even those are charge controllers.
Can you elaborate a bit more on what you have?
Renogy told me to use a 12 AWG extension for 20 feet. What's the benefit of 10 AWG?
The benefit of a thicker gauge cable is less loss of voltage. And by the way, the creator of these amazing videos passed away in June 2022.
What if rv has solar is it safe to connect both?
Great series. Thx! Question please. I am currently using Config 5 with my Renogy 100w briefcase on my camper. I was thinking about going to Config 7 which is why I found your videos. I think you are saying that if I add a panel I must switch out the PWM controller for a MPPT? Is that correct? And why if don't mind. Thx again? Scott
PS: It's a 20a PWM controller. I would like to add a 100w Renogy Eclipse to my 100w Renogy briefcase.
It might be helpful to review my video on the differences between PWM and MPPT controllers: ruclips.net/video/EjCUR9jFphc/видео.html
In configuration 7, a second solar panel is added in series with the first one. This results in the voltage on the solar input terminals of the PWM controller to be 36V. It cannot handle this voltage, and it's a waste of a panel.
The PWM controller cannot convert one voltage to another, but it simply discards the additional voltage as heat. So it would have to discard 36V (solar panel voltage) - 14V (battery charge voltage)... or 22V. 22V@5.5A = 121 Watts. This excess energy would burn up the controller.
So when you add a second panel in series to a PWM controller, you increase the voltage which requires the controller to get rid of, but you see no improvement in charger performance.
A MPPT controller can convert a higher voltage to a lower voltage, so it converts 36V @ 5.5A from the solar panel to 14V @ 13A at the battery.
While you could wire the second panel in parallel with the existing panel and use your existing PWM controller, you are again wasting energy because the series resistance in the wiring will start to become an issue. You would likely have to increase the AWG of the wiring to obtain the best performance in this situation.
A high quality Victron 75/15 controller is about $100, so it is not a really costly item. In fact, compared to wiring the two panels in parallel, the cost new heavy duty wire would offset much of the cost of the MPPT controller.
And a MPPT controller is also about 10% more efficient than a PWM controller.
Also, if you are going to add new panels, especially in series, I highly recommend buying the same brand, model, and specification panel.
That is so clear and helpful. I really appreciate it. Thx!
Scott
Oh thank you!
Welcome.
Just a question, if the fuse pops with no power to the mppt will that cause any damage to the controller. Thank you.
Fuses blow for one reason only - an overcurrent condition. Depending on why the fuse blows, it could cause damage to something.
Another really good video, love these, you said something that got me worried though, (some rv manufacturers dont actually plug the furrion port to the battery, therefore you have to do that yourself). 2 months ago, i purchased a forest river salem fsx, actual model is the 178bhsk. Anyhow, one of the things i liked so much about it was the furrion port, being, solar ready...Was your Grand Design furrion port already plugged to the battery? I hope my forrest river is...
I just looked back at one of the videos, noticed your furrion port wasnt already plugged to the battery...Is that complicating to do? Can you make a video showing how to do that?
I think it's typical that the RV companies don't connect the port of the battery. But it is simple to do, Red wire from the solar port to the battery positive, black wire to battery negative.
@@RVProject curious to what that look like
@@49ers49ers Grand Design ships their units without a battery, and as part of the sale, the dealer typically installs the battery, so it's up to them whether or not the Furrion port is connected.
The dealer did not connect the port when I bought my Grand Design 29RS, and feedback from many other owners of GD and other brand RV, it appears that dealers typically leave the port disconnected.
I would suggest looking in the battery compartment and see if it looks like there is a set of mystery wires not connected to anything.
Or, using a multimeter (voltage scale) measure the pins on the Furrion connector. If connected, it will read the battery voltage.
I'm surely missing something so my apologies but referencing configuration 8, why is the upgraded MPPT controller needed if 11amps are coming in and it's rated for 15amps?
Because the two panels are wired in series, which results in almost 40VDC input to the controller. Only a MPPT controller can handle this higher voltage, and in effect, it converts the higher voltage into additional current.
A PWM controller can only handle around 18VDC or so coming from the solar panels. The excess voltage would need to be dissipated by the controller, which it is really not designed to do, and would likely overheat and eventually damage the PWM controller.
To look at it another way:
MPPT controller connected to two 200W solar panels in series will provide 14.4VDC @ 22 to 26Watts (the MPPT controller is efficient at converting voltage to current).
PWM controller connect to two 200W solar panels in series will provide 14.4VDC @ 11Watts - with 11Watts needing to be dissipated. So you are really wasting money on the second panel as all of it's energy is being converted to waste heat.
So in reality, when connecting these panels in series, you must use a MPPT controller as a PWM controller cannot handle the higher input voltage.
Of course, you could connect the panels in parallel with a PWM controller, but then you are going to have some voltage loss in the extension wire, and loss of conversion efficiency.
Comparing the two; the MPPT controller will be something like 93% efficient, while the PWM controller might only be around 75% efficient, depending on the AWG and length of extension cable from the controller to the panels.
I do explain the differences between PWM and MPPT and series vs. parallel in my suitcase video series: www.rv-project.com/projects/suitcase.php
@@RVProject I understand the need for an MPPT vs. PWM, but for example I'm running a Victron MPPT 100/15 and thought I could upgrade my 200w system later to 400w (configured like your #8) and because my voltage would be coming in at 36v and amperage at 11amps I would not need to upgrade the MPPT controller but it appears the output amperage from the MPPT controller to the battery is too high, thus requiring the updated MPPT controller?
@@joshhaas2410 The Victron part number scheme is a bit confusing, but:
MPPT Input Voltage/Output Current
So MPPT 75/15 can handle up to 75V input, but can only deliver 15A output.
MPPT 100/30 has a 100V input capability, and 30A output capability.
Since you can potentially see up to 26A on the output current of the controller with two 200W solar panels, a 15A controller won't work.
@@RVProject Thank you, that explains it. I wish I had read the specs closer when I originally purchased the controller as I thought I was good for the upgrade but should not have assumed 15amp was only pointing to the input side when it's both input and output. Darn.
Help please . 100 watt panel / 20a mppt charge controller / 100 LiFePO4 battery ... what size fuse between charge controller & battery , thanks .
The creator of these amazing videos passed away in June 2022
@@campusa8742 So sorry .
I can't figure this out :( - I hope someone can help me. I have a 100W Jackery solar panel - How do I connect it to my Winnebago Micro Mini camper? Do I need an 8mm to MC4 connector? Please help!
The creator of these amazing videos passed away in June 2022. I hope somebody else will chime in and answer your question for you.
I loved the series! Thank you so much for putting this together. May I get clarification on Configuration 8? You upgraded the MPPT controller to 100/30 to accommodate the potential for 26 amps of charge current. Is this just in case the panels are hooked up in parallel? If hooked up in series (as shown in the diagram), wouldn't it stay at 11 amps and still be within specs of the original MPPT controller?
My setup has turned out pretty awesome however I’m noticing my 2x 100w panels in series are very picky with the sun and any tiny amount of shading seriously degrades the output given the 2 panels are in series. Like from 175w down to 30w. Wow! It’s left me wondering; even though I’ve gained in the area of very little voltage line loss what are your thoughts on switching to parallel, having a bit of line loss and not having shade on one cell completely screwing the output of both, being they’re wired as a string?
Make sure you have bypass diodes installed in your setup. These diodes are critical when wiring the panels in series as they prevent the exact issue you are describing.
@@RVProject Thanks, I'll being researching now. Another idea for a video! =)
@@RVProject According to Rich Solar, bypass diodes are already onboard.
@@RVProject Opened the box and verified as well. Hmmmm
@@joshhaas2410 I would verify it. Would not be the first time something like that was left off.
Are you concerned with someone walking away with your solar panels? I want to use them, but usually go hiking during daytime and am concerned with someone possibly walking away with them from the campsite if I am not there. Any thoughts?
There is always that possibility.
I was thinking the same thing. Maybe a chain connecting them and a dummy security camera pointing at them??
If we are going to be absent any length of time we put our solar suitcase on the roof, lean an unfurled patio umbrella against the cords to somewhat disguise them to a casual glance and block the ladder access.
Can you charge and discharge at the same time. If we are using a battery bank and charging that from solar, is there any reason why I can't use the power from the battery bank at the same time I am charging that battery bank.
Yes. If you connect a solar panel to your RV battery while it is in use, then you are both charging and discharging at the same time. This is the typical method of operation.
@@RVProject Now that wouldn't work on a solar generator would it ?, or is that still the same? I know you can obviously charge a solar generator from a solar panel, that's one of the ways of recharging, but I've never really heard anyone say anything about being able to discharge at the same time your charging on a solar generator.