Very good explaining. I have a portable suitcase and needed a 10 meter extension but I had a guess that I should mount the controller closer to the battery. This video confirmed my guess. Thank you so much
This s a GREAT video and explains what people really need to understand and almost no one does understand!! Must see TV! lol. I learned this big time when I moved from Lead Acid batteries to Lithium Batteries (Battleborn) and moved them to under the bed in my trailer, and did not move the battery charger. I had a 90amp charger but only got 15amp charging! The wire run was way to long and the wire gauge was way to small, the voltage drop was huge. Lithium REQUIRES that high voltage to charge appropriately. You can sort of get away with it for Lead Acid, but not with Lithium. I upgraded my wiring to 1o and worked hard to cut the wire length and I now can get almost 80amp charging rates to my 2 100ah batteries.
It seems to be a common mistake. I saw a video of a guy that used 50ft of extension cord and put MC4 connectors on the ends, which is why I keep mentioning it in my videos. He said it still worked, but I bet he never looked at the maximum charge rate.
Why do you not mention putting the panels in series and using a MPPT controller at the battery end of the wiring? Your voltage drop calculator does not allow voltages higher than 14 volts.
In my suitcase video series, I cover MPPT controllers in videos 5 and 6. Here is the complete Project Video List: Video 1: Review of the Renogy 100Watt Solar Suitcase: th-cam.com/video/A3j5PwwWwiI/w-d-xo.html Video 2: Connecting a Suitcase panel to your RV: th-cam.com/video/7-rsq3Wc5as/w-d-xo.html Video 3: Voltage Drop Issues and extension cables: th-cam.com/video/A6PxSvuGc5U/w-d-xo.html Video 4: Installing a PWM Charge Controller in a RV: th-cam.com/video/_hDwUKKs7q0/w-d-xo.html Video 5: PWM vs. MPPT Charge Controllers: th-cam.com/video/EjCUR9jFphc/w-d-xo.html Video 6: Upgrading to a MPPT Charge Controller: th-cam.com/video/yxVfId-TW9A/w-d-xo.html Video 7: Series and Parallel Solar Panel connections: th-cam.com/video/0Ufm9HHGdQs/w-d-xo.html Video 8: Charging a Jackery 500 with the Renogy Suitcase: th-cam.com/video/7Peqe4CyUH8/w-d-xo.html Video 9: Upgrade the Furrion solar port for more Amps: th-cam.com/video/cbKWRvz0SOU/w-d-xo.html Video 10: Eight common connection configurations: th-cam.com/video/VUoZ7AO94w8/w-d-xo.html Video 11: Yet another Furrion Solar Port Video: th-cam.com/video/0hYQzNuXikc/w-d-xo.html You are correct that the voltage drop calculator only goes up to 14V, because I had to quit somewhere. Depending on the calculator you use, the voltage is not really a significant factor. For example, if you use the "acceptable voltage drop" calculator, the "supply voltage" is used to determine what a 3% or 10% voltage drop would result in. Or, in the "voltage drop for a given wire size" calculator, the resulting voltage will be accurate regardless of what voltage you enter for the "supply voltage". The supply voltage in this case is only used to determine the percentage of voltage drop, not the actual voltage. So you can work around the 14V limit of the calculator, especially if you use the "given wire size" calculator. You can use any input voltage, and the "Voltage Drop" value will still be the same. You would disregard the voltage drop percent and load voltage values if you used a voltage outside of the supply voltage. For example, if you needed to solve for 48V, you could enter 12V into the calculator's source voltage in the "given wire size" calculator. The voltage drop would be an accurate voltage, but the percent and load voltage would not, as those are based on 12V. However, on my High Power DC Wiring page - which is an associated page to the voltage drop calculator (www.rv-project.com/tips/dcwiring.php) I do provide the actual formula for determining the voltage drop. Voltage drop or other values can be calculated from the different iterations of the formula: CM = (K x I x L) / E I = (E x CM) / (K x L) L = (E x CM) / (K x I) E = (K x I x L) / CM Where E = voltage K = 10.75, which is a constant for copper wire I = Current in Amps L = Round Trip distance in feet. CM = Circular Mils. Circular mils is essentially the cross section of the wire, and I have a chart on that webpage for each AWG of common wire. However, this is somewhat generic as individual wire manufacturers sometimes publish slightly different CMs for their wire, especially if the wire is SAE (which is 10% or so smaller than AWG). Hope this helps.
Although there is significant voltage drop if you use an extension cord greater than 15 ft,, a lower voltage is better than no voltage at 15 ft if the is no sun when surrounded by trees parked in the shade.
From my website, there is an overall webpage for the project. All of the videos are indexed here: www.rv-project.com/projects/suitcase.php Video 1: th-cam.com/video/A3j5PwwWwiI/w-d-xo.html Video 2: th-cam.com/video/7-rsq3Wc5as/w-d-xo.html In the video description, I also list all of the videos in the series.
Well I use 20 ft + extensions on 8mm barrel connectors to several brand solar 100w briefcase panels. I just see 70-80w produced instead of closer to 100w, which is not a big deal to me if my TT can be in shade and I can move the panels around to catch the sun. I have found that short extensions (10ft) are a waste of time for my needs
Hello. Last week, I bought a Renogy foldable 200w solar panels SKU #RNG-KIT-STCS200D-VOY20. I am looking for answer concerning the possibility to add an extension to my kit. I read alote on the subject but it's not very clear for me because I am newbie with solar and I don't want to waste my money. With this kit, can I add an extension somewhere between the controler and the battery? All the wires that came with the kit are gauge #14 (verified with Renogy staff) Do I have to use #10 gauge for this extension and what is the maximum for the lenght? What is the voltage loss expected? Actually, the kit is hooked directly to the battery 12V lead acid 105 ah because I realized that Renogy made this kit to be installed on the battery and not by using any pre installed port on the rv trailer (their graphic show the installation this way!) Maybe to optimize the kit! On my rv trailer, there is a SAE port ( ZAMP) and the wire seem to be 12 or 14 gauge. Another option is maybe to replace the entire wires between the controler and the battery with all gauge # 10 instead of gauge # 14 ?
So I understand you want to add another 200W solar panel to your portable setup? A 200W panel pair will output maybe 11A max and around 18VDC at the best angle and brightest sun. Two 200W panels will obviously double the output. You have basically two options, both of which would require configuration of the panels. First you can wire the two panel pairs in parallel with the charge controller at the panels. Your charge controller would have to be rated at least for 25A, so that might mean you may have to replace the controller with a heavier duty unit. And you can use my on-line voltage drop calculator ( www.rv-project.com/tips/wirecalc.php ) to figure this out, but with a 10AWG wire and 25A current, you would drop 1/2volt for every 10ft of wire. This is a very significant voltage drop, and I would not be comfortable with it. You are paying more for the additional charge controller, yet you will not be able to use all of the power out of the charge controller as the voltage drop will reduce the charging output. You can run the figures by using my calculator, but even with 6AWG, you are looking at 0.2V per 10ft which is still fairly significant. You will end up spending a lot of money on wiring, and potentially have to buy a new charge controller. My recommendation would be to wire the two panel pairs in series, which would result in doubling the voltage output from the solar panels, but the current would still be no more than the 200W panels - which is 11A. This requires a MPPT controller as the PWM controller that probably came with the Renogy panels cannot handle the higher voltage of the panels in series. Secondly, I would wire the MPPT controller to the battery rather than at the solar panels themselves. This means the voltage drop issue is not nearly as significant, and you could get by with up to a 25ft run of 12AWG wire between the panels and battery/charge controller. The reason for this is the charge controller will output a maximum of 14.4VDC, while the panels would be at around 36VDC. This would result in around 1V voltage drop along the 12AWG wire, but since it is on the input side of the charge controller, the lower voltage will not affect the charger's ability to output the maximum current it is capable of. I have over 10 videos in my suitcase solar panel series, and you can find links to them in the description of of this video.
@@RVProject I don't want to add another 200 watts to my original kit but simply, I want to know if I can replace the actual wiring (14 awg) with 10 awg to reduce voltage loss if any? It is not a big job to do it but I don't want to waste money doing so if the genuine kit don't loose too much voltage. With the wiring (14 awg) supplied by Renogy, It measure 12 feet long from the controler to the battery. I would like to have a wiring between 15 feet and 20 feet with 20 awg. Actually, I have just made a 8 days trip with this original kit and I am quite impress with the performance even with cloudy days. Definitly, I recommend it all the ways:)
@@aguertin3846 Sorry for my confusion. Yes you can and should replace your wiring with 10AWG. Renogy also recommends using 10AWG if your cable run is more than 10ft. This is especially true when the charge controller is located at the solar panel. Most modern chargers, including the typical solar chargers are three state chargers. The three states are Bulk/Boost charge (14.4V), Normal/Absorption charge (13.5V), and Trickle/Float charge (12.9V). And for reference, a fully charged battery is 12.6V. You can see here that there is not a lot of difference in voltage from one charge state to another, so that means the charger-to-battery circuit is very voltage sensitive. The best practice would be to locate the charge controller as close as possible to the battery as voltage losses between the solar panel and charge controller are not as critical. So here is what can happen if the voltage drop between the battery and charger is excessive. When a battery is less than 80% charged, the Bulk mode is active, which rapidly charges the battery. This can be thought of as the rapid charge phase. When the battery is between 80% and 100% charged the charger enters normal/absorption charge, which is a moderate charge. It will charge the battery more slowly, but allows the battery to cool down from the Bulk charge. And finally, when the battery becomes 100% charged, the charger enters the trickle mode which is a low level charge designed to keep the battery topped off. While a battery can be fully charged using trickle charge, it might take 16-20 hours to charge. But in the Bulk-Normal-Trickle stages, a battery might charge in 2 hours. So lets say you have a 0.75V drop in your cables from the charger to the battery, and your battery is less than 80% charged, so the boost charge would kick in, which is 14.5VDC. However, after dropping 0.75V along the cable, only 13.75V would reach the battery. This reduces the rapid battery charge rate, so it will take longer to charge the battery in rapid mode. So in effect, you may be paying for a 200W panel, but only getting 100W worth of performance. However, since the charge rate is lower in Normal and Trickle mode, the current will be less, meaning less voltage drop along the wires, so in these two modes, the charging will be fairly unaffected. I would absolutely not use anything less than 14AWG if you are under 10ft, and 10AWG for more than 10ft. The higher the AWG, the better the charge performance during rapid charge. If you go much more than 10ft, I would recommend moving the charger from the solar panel to the battery. A Renogy 200W solar panel should output about 18V. In this situation, the voltage drop is not as much of an issue. The charger can handle one or two volt loss along the wire from the solar panel and still output it's rated voltage in rapid charge. Also, 20AWG wire cannot handle 11A from a 200W solar panel, so you would risk melting the wire. The maximum current for 20AWG varies due to the temperature rating of it's insulation, but it is in the range of 3A. And if it could handle the current, you would have such an excessive voltage drop along the wires, the battery would not likely be charged.
@@RVProject sorry again. I made a mistake with the awg size. I don't know why I wrote 20 AWG but the real awg is 10 AWG. Sorry! You are absolutly right when you write about trickle stage. I have noticed that the charger seem to stall after the third light green come on. The fourth light doesnt come on but the charger indicate the battery seem to be charged at 12.9 Volts. So my plan is to change the wires from the charger to direcly to the battery. Renogy sell pigtails and extension and a fuse mounted in a MC4 socket. I could buy 2 pigtails ( one from the charger and the other plugged directly to the battery) 1 x 15 feet extension and a 15 amp fuse. All this wiring in 10 awg and would measure around 17 feet. Good move or not? 10 feet better ? I have use your calculators to see what was going on with voltage drop and let see if I am good or not :) lenght load awg Vdrop % load voltage supply voltage 12 10.5 14 0.661 4.59 13.739 14.4 12 10.5 10 0.258 1.79 14.142 14.4 17 10.5 14 0.936 6.50 13.464 14.4 17 10.5 10 0.365 2.54 14.034 14.4 Thanks again for all info you give
@@aguertin3846 You will have to play with the tradeoffs here. The shorter the cable distance and the largest AWG your pocketbook will tolerate, the better. Even at 10AWG, there is going to be some voltage drop. I would try to keep the voltage loss under 1/2V. Under 1/4V would be all the better.
Awesome video thank you! I'm watching the entire series and learning so much
this is like the high school science teacher that I never had but always needed :(
Very good explaining. I have a portable suitcase and needed a 10 meter extension but I had a guess that I should mount the controller closer to the battery. This video confirmed my guess. Thank you so much
This s a GREAT video and explains what people really need to understand and almost no one does understand!! Must see TV! lol. I learned this big time when I moved from Lead Acid batteries to Lithium Batteries (Battleborn) and moved them to under the bed in my trailer, and did not move the battery charger. I had a 90amp charger but only got 15amp charging! The wire run was way to long and the wire gauge was way to small, the voltage drop was huge. Lithium REQUIRES that high voltage to charge appropriately. You can sort of get away with it for Lead Acid, but not with Lithium. I upgraded my wiring to 1o and worked hard to cut the wire length and I now can get almost 80amp charging rates to my 2 100ah batteries.
It seems to be a common mistake. I saw a video of a guy that used 50ft of extension cord and put MC4 connectors on the ends, which is why I keep mentioning it in my videos. He said it still worked, but I bet he never looked at the maximum charge rate.
👍👌❤️🇨🇦, gr8 info
Why do you not mention putting the panels in series and using a MPPT controller at the battery end of the wiring? Your voltage drop calculator does not allow voltages higher than 14 volts.
In my suitcase video series, I cover MPPT controllers in videos 5 and 6. Here is the complete Project Video List:
Video 1: Review of the Renogy 100Watt Solar Suitcase: th-cam.com/video/A3j5PwwWwiI/w-d-xo.html
Video 2: Connecting a Suitcase panel to your RV: th-cam.com/video/7-rsq3Wc5as/w-d-xo.html
Video 3: Voltage Drop Issues and extension cables: th-cam.com/video/A6PxSvuGc5U/w-d-xo.html
Video 4: Installing a PWM Charge Controller in a RV: th-cam.com/video/_hDwUKKs7q0/w-d-xo.html
Video 5: PWM vs. MPPT Charge Controllers: th-cam.com/video/EjCUR9jFphc/w-d-xo.html
Video 6: Upgrading to a MPPT Charge Controller: th-cam.com/video/yxVfId-TW9A/w-d-xo.html
Video 7: Series and Parallel Solar Panel connections: th-cam.com/video/0Ufm9HHGdQs/w-d-xo.html
Video 8: Charging a Jackery 500 with the Renogy Suitcase: th-cam.com/video/7Peqe4CyUH8/w-d-xo.html
Video 9: Upgrade the Furrion solar port for more Amps: th-cam.com/video/cbKWRvz0SOU/w-d-xo.html
Video 10: Eight common connection configurations: th-cam.com/video/VUoZ7AO94w8/w-d-xo.html
Video 11: Yet another Furrion Solar Port Video: th-cam.com/video/0hYQzNuXikc/w-d-xo.html
You are correct that the voltage drop calculator only goes up to 14V, because I had to quit somewhere. Depending on the calculator you use, the voltage is not really a significant factor.
For example, if you use the "acceptable voltage drop" calculator, the "supply voltage" is used to determine what a 3% or 10% voltage drop would result in.
Or, in the "voltage drop for a given wire size" calculator, the resulting voltage will be accurate regardless of what voltage you enter for the "supply voltage". The supply voltage in this case is only used to determine the percentage of voltage drop, not the actual voltage.
So you can work around the 14V limit of the calculator, especially if you use the "given wire size" calculator. You can use any input voltage, and the "Voltage Drop" value will still be the same. You would disregard the voltage drop percent and load voltage values if you used a voltage outside of the supply voltage.
For example, if you needed to solve for 48V, you could enter 12V into the calculator's source voltage in the "given wire size" calculator. The voltage drop would be an accurate voltage, but the percent and load voltage would not, as those are based on 12V.
However, on my High Power DC Wiring page - which is an associated page to the voltage drop calculator (www.rv-project.com/tips/dcwiring.php) I do provide the actual formula for determining the voltage drop.
Voltage drop or other values can be calculated from the different iterations of the formula:
CM = (K x I x L) / E
I = (E x CM) / (K x L)
L = (E x CM) / (K x I)
E = (K x I x L) / CM
Where E = voltage
K = 10.75, which is a constant for copper wire
I = Current in Amps
L = Round Trip distance in feet.
CM = Circular Mils.
Circular mils is essentially the cross section of the wire, and I have a chart on that webpage for each AWG of common wire. However, this is somewhat generic as individual wire manufacturers sometimes publish slightly different CMs for their wire, especially if the wire is SAE (which is 10% or so smaller than AWG).
Hope this helps.
Although there is significant voltage drop if you use an extension cord greater than 15 ft,, a lower voltage is better than no voltage at 15 ft if the is no sun when surrounded by trees parked in the shade.
There are always compromises, but at least you know what they are...
Help where is video 1 and 2? Cant find them
From my website, there is an overall webpage for the project. All of the videos are indexed here: www.rv-project.com/projects/suitcase.php
Video 1: th-cam.com/video/A3j5PwwWwiI/w-d-xo.html
Video 2: th-cam.com/video/7-rsq3Wc5as/w-d-xo.html
In the video description, I also list all of the videos in the series.
Well I use 20 ft + extensions on 8mm barrel connectors to several brand solar 100w briefcase panels. I just see 70-80w produced instead of closer to 100w, which is not a big deal to me if my TT can be in shade and I can move the panels around to catch the sun. I have found that short extensions (10ft) are a waste of time for my needs
As long as you know the tradeoffs between distance and length, you can make the best decision for you. Sounds like you did that.
Hello. Last week, I bought a Renogy foldable 200w solar panels SKU #RNG-KIT-STCS200D-VOY20. I am looking for answer concerning the possibility to add an extension to my kit. I read alote on the subject but it's not very clear for me because I am newbie with solar and I don't want to waste my money.
With this kit, can I add an extension somewhere between the controler and the battery? All the wires that came with the kit are gauge #14 (verified with Renogy staff) Do I have to use #10 gauge for this extension and what is the maximum for the lenght? What is the voltage loss expected? Actually, the kit is hooked directly to the battery 12V lead acid 105 ah because I realized that Renogy made this kit to be installed on the battery and not by using any pre installed port on the rv trailer (their graphic show the installation this way!) Maybe to optimize the kit!
On my rv trailer, there is a SAE port ( ZAMP) and the wire seem to be 12 or 14 gauge.
Another option is maybe to replace the entire wires between the controler and the battery with all gauge # 10 instead of gauge # 14 ?
So I understand you want to add another 200W solar panel to your portable setup?
A 200W panel pair will output maybe 11A max and around 18VDC at the best angle and brightest sun. Two 200W panels will obviously double the output.
You have basically two options, both of which would require configuration of the panels.
First you can wire the two panel pairs in parallel with the charge controller at the panels. Your charge controller would have to be rated at least for 25A, so that might mean you may have to replace the controller with a heavier duty unit.
And you can use my on-line voltage drop calculator ( www.rv-project.com/tips/wirecalc.php ) to figure this out, but with a 10AWG wire and 25A current, you would drop 1/2volt for every 10ft of wire.
This is a very significant voltage drop, and I would not be comfortable with it. You are paying more for the additional charge controller, yet you will not be able to use all of the power out of the charge controller as the voltage drop will reduce the charging output.
You can run the figures by using my calculator, but even with 6AWG, you are looking at 0.2V per 10ft which is still fairly significant.
You will end up spending a lot of money on wiring, and potentially have to buy a new charge controller.
My recommendation would be to wire the two panel pairs in series, which would result in doubling the voltage output from the solar panels, but the current would still be no more than the 200W panels - which is 11A.
This requires a MPPT controller as the PWM controller that probably came with the Renogy panels cannot handle the higher voltage of the panels in series.
Secondly, I would wire the MPPT controller to the battery rather than at the solar panels themselves. This means the voltage drop issue is not nearly as significant, and you could get by with up to a 25ft run of 12AWG wire between the panels and battery/charge controller.
The reason for this is the charge controller will output a maximum of 14.4VDC, while the panels would be at around 36VDC. This would result in around 1V voltage drop along the 12AWG wire, but since it is on the input side of the charge controller, the lower voltage will not affect the charger's ability to output the maximum current it is capable of.
I have over 10 videos in my suitcase solar panel series, and you can find links to them in the description of of this video.
@@RVProject I don't want to add another 200 watts to my original kit but simply, I want to know if I can replace the actual wiring (14 awg) with 10 awg to reduce voltage loss if any? It is not a big job to do it but I don't want to waste money doing so if the genuine kit don't loose too much voltage.
With the wiring (14 awg) supplied by Renogy, It measure 12 feet long from the controler to the battery.
I would like to have a wiring between 15 feet and 20 feet with 20 awg.
Actually, I have just made a 8 days trip with this original kit and I am quite impress with the performance even with cloudy days. Definitly, I recommend it all the ways:)
@@aguertin3846 Sorry for my confusion.
Yes you can and should replace your wiring with 10AWG. Renogy also recommends using 10AWG if your cable run is more than 10ft.
This is especially true when the charge controller is located at the solar panel.
Most modern chargers, including the typical solar chargers are three state chargers. The three states are Bulk/Boost charge (14.4V), Normal/Absorption charge (13.5V), and Trickle/Float charge (12.9V).
And for reference, a fully charged battery is 12.6V.
You can see here that there is not a lot of difference in voltage from one charge state to another, so that means the charger-to-battery circuit is very voltage sensitive.
The best practice would be to locate the charge controller as close as possible to the battery as voltage losses between the solar panel and charge controller are not as critical.
So here is what can happen if the voltage drop between the battery and charger is excessive.
When a battery is less than 80% charged, the Bulk mode is active, which rapidly charges the battery. This can be thought of as the rapid charge phase.
When the battery is between 80% and 100% charged the charger enters normal/absorption charge, which is a moderate charge. It will charge the battery more slowly, but allows the battery to cool down from the Bulk charge.
And finally, when the battery becomes 100% charged, the charger enters the trickle mode which is a low level charge designed to keep the battery topped off.
While a battery can be fully charged using trickle charge, it might take 16-20 hours to charge. But in the Bulk-Normal-Trickle stages, a battery might charge in 2 hours.
So lets say you have a 0.75V drop in your cables from the charger to the battery, and your battery is less than 80% charged, so the boost charge would kick in, which is 14.5VDC. However, after dropping 0.75V along the cable, only 13.75V would reach the battery.
This reduces the rapid battery charge rate, so it will take longer to charge the battery in rapid mode. So in effect, you may be paying for a 200W panel, but only getting 100W worth of performance.
However, since the charge rate is lower in Normal and Trickle mode, the current will be less, meaning less voltage drop along the wires, so in these two modes, the charging will be fairly unaffected.
I would absolutely not use anything less than 14AWG if you are under 10ft, and 10AWG for more than 10ft. The higher the AWG, the better the charge performance during rapid charge.
If you go much more than 10ft, I would recommend moving the charger from the solar panel to the battery.
A Renogy 200W solar panel should output about 18V. In this situation, the voltage drop is not as much of an issue. The charger can handle one or two volt loss along the wire from the solar panel and still output it's rated voltage in rapid charge.
Also, 20AWG wire cannot handle 11A from a 200W solar panel, so you would risk melting the wire. The maximum current for 20AWG varies due to the temperature rating of it's insulation, but it is in the range of 3A.
And if it could handle the current, you would have such an excessive voltage drop along the wires, the battery would not likely be charged.
@@RVProject sorry again. I made a mistake with the awg size. I don't know why I wrote 20 AWG but the real awg is 10 AWG. Sorry!
You are absolutly right when you write about trickle stage. I have noticed that the charger seem to stall after the third light green come on. The fourth light doesnt come on but the charger indicate the battery seem to be charged at 12.9 Volts.
So my plan is to change the wires from the charger to direcly to the battery. Renogy sell pigtails and extension and a fuse mounted in a MC4 socket. I could buy 2 pigtails ( one from the charger and the other plugged directly to the battery) 1 x 15 feet extension and a 15 amp fuse. All this wiring in 10 awg and would measure around 17 feet. Good move or not? 10 feet better ?
I have use your calculators to see what was going on with voltage drop and let see if I am good or not :)
lenght load awg Vdrop % load voltage supply voltage
12 10.5 14 0.661 4.59 13.739 14.4
12 10.5 10 0.258 1.79 14.142 14.4
17 10.5 14 0.936 6.50 13.464 14.4
17 10.5 10 0.365 2.54 14.034 14.4
Thanks again for all info you give
@@aguertin3846 You will have to play with the tradeoffs here. The shorter the cable distance and the largest AWG your pocketbook will tolerate, the better. Even at 10AWG, there is going to be some voltage drop.
I would try to keep the voltage loss under 1/2V. Under 1/4V would be all the better.