Excellent explanation. I'm starting in solar and we'll need assistance and will probably reach out to you guys I would rather have someone with the knowledge and expertise as a vendor
+closertothetruth Excellent point. Cheap off-brand "MPPT" charge controllers don't do true multipoint tracking. Be sure to look for brand name MPPT charge controllers. If the price is too good to be true, it probably is.
Well i have a EPEVER MPPT and it is soooo slow tracking when its cloudy. It takes forever for it to deside which voltage is best. And when its found, the sun is gone behind a cloud.Why does it have to take soo long time?
Ok so to be sure, can I put a 24v nominal solar panel on a pwm controller? I have had many customers at my place of employment have pwm controllers nearly set fire to their homes doing this type of connection. I'm confused as to why.
You can put a 24V nominal panel on a PWM charge controller to a 24V battery bank. The people having problems were probably trying to get it to charge a 12V battery, which then tries to put far too high of a voltage at the battery.
@@AltEStore that's exactly it. I've had actual electricians tell me that you can put a 24v panels on a 12v system using a pwm controller. Friends of mine told me that they are wrong but I wanted to be sure.
Why is pwm charge controller called "PWM"(pulse width modulation) where the is pulse width modulation in pwm charge controller? Can someone explain that to me ?
Thanks, you clearly demonstrated the MPPT controllers advantages. However, you are noting panels specs at STC, i.e., with a panel surface temp of 25 C. This is somewhat of an artificial or laboratory setup. As we all know summertime conditions would significantly raise the panels surface temp and consequentially reduce the panel Vmp by on average (-) 0.4 V per degree C. So this will reduce both overall system voltage and max power output. Therefore, driving down the voltage closer to that of the storage batteries. This, therefore, may make the analysis of which charge controller to use a little more tricky.
If I have two 100w solar panels hooked up in series 17.8Vmp x 2 = 35.6Vmp, The battery bank is 21V - 29.4V or 25.2V nominal, What is best for this scenario?
Are you losing a lot of power if you are using a 24 volt PWM charge controller, 24 volt solar array (38 Voc) to charge a 24 volt battery bank - compared to MPPT?
Under some conditions, an MPPT can increase the output over PWM by as much as 25- 30%. But on smaller systems, the difference isn't as great. We'll be doing a video some comparing actual charge controllers.
i am kinda new to this and I've already ordered my parts to make an off grid system. Will a 17V solar panel (which is supposedly be 12 volt panel when i bought it) be able to charge a 14.5 V rechargeable battery(that is suppose to be 12 volt when i ordered)? And i don't get the amps in the charge controllers. (i just ordered a 10 amp since many people say it'll work in a 12-24 volt system)
+Killerfrozen The 12V is nominal, it is the category it is in. They use that for the exact reason you are talking about; a 12V panel actually puts out 17V and a 12V battery bank when full is around 14V. You need a higher voltage power source (the solar panel) to charge a lower voltage battery.
+Killerfrozen I assume you mean you have a 7 amp hour (Ah) battery. If you have a 10W solar panel, that is 10 Watts / 17 Volts = .58 amps. So you could use a tiny charge controller, less than an amp. 20A is much bigger than you needed. To use very rough numbers, if you have a 7Ah battery, and use only 50%, that is 3.5Ah that you need to recharge. If your solar panel is putting out .5 amps, it will take 3.5Ah / .5A = 7 hours of full sun. So it will take about 2 days to charge.
I'm not sure in what context you are referring to the terms, but I can answer in general. A constant current source provides a steady amperage, regardless of if the voltage is changing. For example, if the power is changing from the source, the amps will stay the same, while the voltage changes. Likewise, a constant voltage source will vary the current, while keeping the volts the same. I hope that helps.
+Joseph Joe When the charge controller drops the solar panels volts down to the battery voltage, the amps are raised up by the same percentage. So the solar panels drop from 18V down to 13V of the battery, 18V / 13V = 1.38. Then the current is raised the same amount, 5.56A x 1.38 = 7.7A.
Why wouldn't you just use 14.5 volt panels instead of 18 volt ?? ( .52V x 28 = 14.5V) The improvement of MPPT is then only 12% (not the 29% of 18 volt panels)
Panels are designed with higher voltage than required under lab conditions to deal with temperature derating, dirty glass, etc. If you want to run lower Voc panels you can look at amorphous; they tend to run lower than poly or mono.
Ignoring the efficiencies as stated, Technically speaking, there is some misinformation in this video. (Marketing I guess) It is impossible to charge a battery with no potential difference. Charge current would not flow. PWM Charge controllers do not lower their voltage to match the battery until the final stage of charging. Pulse Width Modulation is a technique for controlling the output voltage by means of ON/OFF time averaging. During bulk charge cycles the PWM circuit is passing full array voltage @ 100% pulse width to the batteries. As the battery voltage raises the PWM circuit begins to reduce it's output to prevent gassing and over-charging. During the float phase of charge the PWM circuit maintains the output voltage slightly above the full charge voltage of the batteries.
These examples exaggerate realistic performance. For example, the battery charging at 11 volts scenario is not merely a "low" battery, it is one that has probably been damaged beyond any real hope of recovery. Comparing MPPT with PWM where the panel voltage is mismatched for the controller is a silly comparison. The video neglects to mention some significant limitations and some benefits of MPPT. During the absorption charging cycle, which is where a properly sized battery bank and solar array should be operating the majority of the time, batteries are not able to accept a charge at as high a rate as the panels and controller are able to produce and any efficiency advantage of MPPT is irrelevant. During low light conditions an MPPT may be able to deliver a small charge when PWM delivers little or nothing. Most of the extreme efficiency examples of MPPT will seldom be a significant factor under normal conditions. If you want a controller to charge your batteries efficiently with solar power, the charging set point voltages must be matched to the maximum limits of the batteries that are being charged. Many MPPT controllers have set point voltages that are too low for optimum performance and can not be adjusted to correctly match the requirements of the batteries. Many controllers are set to protect batteries from over charging but instead damage the batteries through persistent under charging. Buyers Beware: it is easier for merchants to sell the higher profit MPPT controllers on their efficiency advantages than it is to take the time to match a controller to a battery banks charging set point voltage requirements. Pay close attention to the final two minutes of this video comparing MPPT to PWM. MPPT's are seldom the wisest choice for systems of 500 watts or less except when there is no unshaded space left to add more panels or it is impractical to use large enough wire to carry the current loads of panels with output voltage that is matched to a PWM controller.
Thanks for your feedback. We are planning some outdoor demo videos showing MPPT and PWM charge controllers working with different size systems, from 50W to around 500-600W. We'll try to show some of the points you are making.
Add a load during absorption and see how irrelevant MPPT is. Not sure why you think MPPT setpoints are more likely to be set incorrectly and nonconfigurable.
The way most sellers calculates is right but not and I will explain why. A PWM controller is only a switch on and off . When your battery bank reaches 13.8 volt the switch turns off and when they reach 13.2 volts it turns back on again. So the real way to calculate the PWM is 18 volts in your battery bank at 5.56 amps now this is 100 watts. The solar industry increase the sales of MPPT by calculating the way its done in this video. This not a wrong video its just the way the industry teaches us. Now the MPPT is a much better controller and I must say 90% of people go back and buy a MPPT after a year or so. Lets say you have a draw of 1.3 amps the MPPT will send a charge to the battery bank of 1.3 amps with your voltage staying virtually the same. But both controller are both charging the full 100 watt in this case just wrong measurements.
Check out our video where we show you a PWM vs MPPT charge controller with a 24V solar panel and a 12V battery, using both an MPPT and a PWM charge controller. ua-cam.com/video/V2b7z2eTb5o/v-deo.html
+Whats GoingOn -- That is so wrong I don't think it would be worth trying to explain to you how it really works. I am replying only to let newbs know not to pay any attention to your nonsense.
why use the given (value) wattage of 12v 100w sys (18Vmp 5.56A) to get 2.78A for ex. 12v 100w +12v 100w series= 24v 200w ; same(( (36Vmp 5.56A) so 24v 200w sys just add 1 panel(100w) to reciprocate the value of 12v sys... what i observed the bottom line is the budget and space for the set-up.... why i defend pwm coz i used it hahahahaa....
+Tabangi Ginoo We sell many PWM charge controllers. I'm also a big fan of the price/performance. But if you have limited space, and can't add a 3rd panel, for example on a boat or RV, or a small cabin, sometimes adding a 3rd panel is not an option. And also, as described, if you don't have 12V panels, but instead are using 20V panels, an MPPT can be worth the extra money. Squeezing an extra 25 - 30% of power out of your panels is a pretty nice thing to have an MPPT for.
Even the cheapest PWM controller will have a max input voltage of 50 volts. Older MPPT models some would be a max input of 75 volt . Go look at specks and try to find a true MPPT under 75 volt . I'm not saying it can't be done . What I'm saying is if your going to buy an MPPT controller today and you want to make sure its a real MPPT look for a max PV input of 100 volts and it will be a true MPPT
Wow, this video is almost identical to a video by Australian Direct. ua-cam.com/video/wmyuxKmlBCk/v-deo.html Did this example come from a solar controller manufacturer's website, or a sales
Woah, you are right. I wrote the presentation in 2014, picked a random example to use. Theirs is in 2016. So unless time travelling is involved, somebody's got some explaining to do. They do say imitation is a form of flattery....
Well, I think there are a lot of people like me who really appreciate all the time and effort that goes into making these videos. They have really helped me learn enough about solar to get started planning the kind of system I want to install in a few years (as soon as we replace our old roof).
Thanks so much Jess. I just met a woman at the big SPI show in Las Vegas this week. She's in the Middle East, and translates a bunch of our videos into Arabic and records her own version for them to learn. Not for profit, but just to spread knowledge. I thought that was really cool.
This doesn't make any sense. The charge controllers have to overcome the internal resistance of the battery and its voltage in order to charge the battery. Lowering the voltage does not increase the current going into the battery. On the contrary, it will only slow it it down. The formula, I=V/R, expresses is very clearly. Those things you explained in the video will only work if batteries have no internal resistance. Unfortunately, No such battery exist.
As the MPPT charge controller isolates the solar panel from the battery, it is able to increase the current output capability of the charge controller. With PWM, the panel is just connected straight to the battery with pulses, so any extra power potential is just thrown away. So it's more than just ohm's law at play. You can see us do a demo of it here, ua-cam.com/video/V2b7z2eTb5o/v-deo.html
I've watched the video and also researched more about the topic. I think I understand now how both Charge controllers work. Thanks for clarifying it for me.
Why is pwm charge controller called "PWM"(pulse width modulation) where the is pulse width modulation in pwm charge controller? Can someone explain that to me ?
Why is pwm charge controller called "PWM"(pulse width modulation) where the is pulse width modulation in pwm charge controller? Can someone explain that to me ?
I’m not 100% confident, but I believe once the bulk charge stage has occurred and the charger controller is going into “float” mode, because it doesn’t have a DC-DC converter like MPPT does, the only way it can provide smaller currents is to use pulses, where width is the amount of current desired.
Best breakdown and info I've seen on UA-cam on these two yet.
Very informative presentation. Thank you.
Thanks for the video very Educative
Very informative
Thanks a lot
I have a question pls. Which kind of method of control do you use in MPPT? sliding mode control?
I love this, very informative thank you
Excellent explanation. I'm starting in solar and we'll need assistance and will probably reach out to you guys I would rather have someone with the knowledge and expertise as a vendor
Very informative, Great Video nice tutorial Thanks William Orange county, ca.
good explanations 👍
a key point also to watch out for fake mppts . True mppt's, and high speed tracking is great.
+closertothetruth Excellent point. Cheap off-brand "MPPT" charge controllers don't do true multipoint tracking. Be sure to look for brand name MPPT charge controllers. If the price is too good to be true, it probably is.
Well i have a EPEVER MPPT and it is soooo slow tracking when its cloudy. It takes forever for it to deside which voltage is best. And when its found, the sun is gone behind a cloud.Why does it have to take soo long time?
Very Helpful video!
Ok so to be sure, can I put a 24v nominal solar panel on a pwm controller? I have had many customers at my place of employment have pwm controllers nearly set fire to their homes doing this type of connection. I'm confused as to why.
You can put a 24V nominal panel on a PWM charge controller to a 24V battery bank. The people having problems were probably trying to get it to charge a 12V battery, which then tries to put far too high of a voltage at the battery.
@@AltEStore that's exactly it. I've had actual electricians tell me that you can put a 24v panels on a 12v system using a pwm controller. Friends of mine told me that they are wrong but I wanted to be sure.
Why is pwm charge controller called "PWM"(pulse width modulation) where the is pulse width modulation in pwm charge controller?
Can someone explain that to me ?
Thanks, you clearly demonstrated the MPPT controllers advantages. However, you are noting panels specs at STC, i.e., with a panel surface temp of 25 C. This is somewhat of an artificial or laboratory setup. As we all know summertime conditions would significantly raise the panels surface temp and consequentially reduce the panel Vmp by on average (-) 0.4 V per degree C. So this will reduce both overall system voltage and max power output. Therefore, driving down the voltage closer to that of the storage batteries. This, therefore, may make the analysis of which charge controller to use a little more tricky.
Thank you!
If I have two 100w solar panels hooked up in series 17.8Vmp x 2 = 35.6Vmp, The battery bank is 21V - 29.4V or 25.2V nominal, What is best for this scenario?
Two 12V panels in series is 24V nominal. Your battery bank is also 24V nominal. With only 200W, you can certainly use a PWM charge controller.
Good comparison
Are you losing a lot of power if you are using a 24 volt PWM charge controller, 24 volt solar array (38 Voc) to charge a 24 volt battery bank - compared to MPPT?
Under some conditions, an MPPT can increase the output over PWM by as much as 25- 30%. But on smaller systems, the difference isn't as great. We'll be doing a video some comparing actual charge controllers.
Maybe you can do a comparison with 60 cell modules versus smaller ones.
i am kinda new to this and I've already ordered my parts to make an off grid system. Will a 17V solar panel (which is supposedly be 12 volt panel when i bought it) be able to charge a 14.5 V rechargeable battery(that is suppose to be 12 volt when i ordered)? And i don't get the amps in the charge controllers. (i just ordered a 10 amp since many people say it'll work in a 12-24 volt system)
the panel is 10 watt so.... i have no idea if t'll effect the 7 amp rechargeable battery or not..
+Killerfrozen i meant a 20 a 12/24 V charge controller
+Killerfrozen The 12V is nominal, it is the category it is in. They use that for the exact reason you are talking about; a 12V panel actually puts out 17V and a 12V battery bank when full is around 14V. You need a higher voltage power source (the solar panel) to charge a lower voltage battery.
+Killerfrozen I assume you mean you have a 7 amp hour (Ah) battery. If you have a 10W solar panel, that is 10 Watts / 17 Volts = .58 amps. So you could use a tiny charge controller, less than an amp. 20A is much bigger than you needed. To use very rough numbers, if you have a 7Ah battery, and use only 50%, that is 3.5Ah that you need to recharge. If your solar panel is putting out .5 amps, it will take 3.5Ah / .5A = 7 hours of full sun. So it will take about 2 days to charge.
Thank you! Will the solar panel still charge the battery through the controller? :-:
I have a 4x100w 17.5v array, is my mppt epever 4215bn 40a cc overkill?
Hi, so your panels are about 100/17,5=5,7a and you have 4
Hi, friend!
You forgot to answer my question. What is constant current and constant voltage?
Thank you!
I'm not sure in what context you are referring to the terms, but I can answer in general. A constant current source provides a steady amperage, regardless of if the voltage is changing. For example, if the power is changing from the source, the amps will stay the same, while the voltage changes. Likewise, a constant voltage source will vary the current, while keeping the volts the same. I hope that helps.
this is what i look for.
Hi.. How did you get the 7.7A? Was that 1.38 + 5.56? The total is not 7.7....
+Joseph Joe When the charge controller drops the solar panels volts down to the battery voltage, the amps are raised up by the same percentage. So the solar panels drop from 18V down to 13V of the battery, 18V / 13V = 1.38. Then the current is raised the same amount, 5.56A x 1.38 = 7.7A.
Why wouldn't you just use 14.5 volt panels instead of 18 volt ?? ( .52V x 28 = 14.5V)
The improvement of MPPT is then only 12% (not the 29% of 18 volt panels)
Panels are designed with higher voltage than required under lab conditions to deal with temperature derating, dirty glass, etc. If you want to run lower Voc panels you can look at amorphous; they tend to run lower than poly or mono.
Ignoring the efficiencies as stated, Technically speaking, there is some misinformation in this video. (Marketing I guess) It is impossible to charge a battery with no potential difference. Charge current would not flow. PWM Charge controllers do not lower their voltage to match the battery until the final stage of charging. Pulse Width Modulation is a technique for controlling the output voltage by means of ON/OFF time averaging. During bulk charge cycles the PWM circuit is passing full array voltage @ 100% pulse width to the batteries. As the battery voltage raises the PWM circuit begins to reduce it's output to prevent gassing and over-charging. During the float phase of charge the PWM circuit maintains the output voltage slightly above the full charge voltage of the batteries.
Totally correct....
These examples exaggerate realistic performance. For example, the battery charging at 11 volts scenario is not merely a "low" battery, it is one that has probably been damaged beyond any real hope of recovery. Comparing MPPT with PWM where the panel voltage is mismatched for the controller is a silly comparison. The video neglects to mention some significant limitations and some benefits of MPPT. During the absorption charging cycle, which is where a properly sized battery bank and solar array should be operating the majority of the time, batteries are not able to accept a charge at as high a rate as the panels and controller are able to produce and any efficiency advantage of MPPT is irrelevant. During low light conditions an MPPT may be able to deliver a small charge when PWM delivers little or nothing. Most of the extreme efficiency examples of MPPT will seldom be a significant factor under normal conditions. If you want a controller to charge your batteries efficiently with solar power, the charging set point voltages must be matched to the maximum limits of the batteries that are being charged. Many MPPT controllers have set point voltages that are too low for optimum performance and can not be adjusted to correctly match the requirements of the batteries. Many controllers are set to protect batteries from over charging but instead damage the batteries through persistent under charging. Buyers Beware: it is easier for merchants to sell the higher profit MPPT controllers on their efficiency advantages than it is to take the time to match a controller to a battery banks charging set point voltage requirements. Pay close attention to the final two minutes of this video comparing MPPT to PWM. MPPT's are seldom the wisest choice for systems of 500 watts or less except when there is no unshaded space left to add more panels or it is impractical to use large enough wire to carry the current loads of panels with output voltage that is matched to a PWM controller.
Thanks for your feedback. We are planning some outdoor demo videos showing MPPT and PWM charge controllers working with different size systems, from 50W to around 500-600W. We'll try to show some of the points you are making.
Add a load during absorption and see how irrelevant MPPT is. Not sure why you think MPPT setpoints are more likely to be set incorrectly and nonconfigurable.
The way most sellers calculates is right but not and I will explain why. A PWM controller is only a switch on and off . When your battery bank reaches 13.8 volt the switch turns off and when they reach 13.2 volts it turns back on again. So the real way to calculate the PWM is 18 volts in your battery bank at 5.56 amps now this is 100 watts. The solar industry increase the sales of MPPT by calculating the way its done in this video. This not a wrong video its just the way the industry teaches us.
Now the MPPT is a much better controller and I must say 90% of people go back and buy a MPPT after a year or so. Lets say you have a draw of 1.3 amps the MPPT will send a charge to the battery bank of 1.3 amps with your voltage staying virtually the same.
But both controller are both charging the full 100 watt in this case just wrong measurements.
+Whats GoingOn TRUE!
Check out our video where we show you a PWM vs MPPT charge controller with a 24V solar panel and a 12V battery, using both an MPPT and a PWM charge controller. ua-cam.com/video/V2b7z2eTb5o/v-deo.html
+Whats GoingOn -- That is so wrong I don't think it would be worth trying to explain to you how it really works. I am replying only to let newbs know not to pay any attention to your nonsense.
+Leo Elo -- FALSE! He has zero clue.
@Whats GoingOn
You don't got a clue ..about simpel math
Volt x Amp = Watt ..
FLAT EARTH ZOMBI
MPPT stands for: Maximum Power Point Tracking.
my dingo plasmatonics pwm charge controller 20/20 ..12 24 48 volt it won't work with my single house solar panel 180 watts why ???
why use the given (value) wattage of 12v 100w sys (18Vmp 5.56A) to get 2.78A for ex. 12v 100w +12v 100w series= 24v 200w ; same(( (36Vmp 5.56A) so 24v 200w sys just add 1 panel(100w) to reciprocate the value of 12v sys... what i observed the bottom line is the budget and space for the set-up.... why i defend pwm coz i used it hahahahaa....
+Tabangi Ginoo We sell many PWM charge controllers. I'm also a big fan of the price/performance. But if you have limited space, and can't add a 3rd panel, for example on a boat or RV, or a small cabin, sometimes adding a 3rd panel is not an option. And also, as described, if you don't have 12V panels, but instead are using 20V panels, an MPPT can be worth the extra money. Squeezing an extra 25 - 30% of power out of your panels is a pretty nice thing to have an MPPT for.
One way to be sure its an MPPT is the max input voltage. A real MPPT as a min. of 100 max volt input if it don't well don't buy it
Even the cheapest PWM controller will have a max input voltage of 50 volts.
Older MPPT models some would be a max input of 75 volt .
Go look at specks and try to find a true MPPT under 75 volt . I'm not saying it can't be done . What I'm saying is if your going to buy an MPPT controller today and you want to make sure its a real MPPT look for a max PV input of 100 volts and it will be a true MPPT
Not true. It should be >= 2x Vbatt for efficiency, but MPPT will harvest more power than PWM even < 2x Vbatt.
MPPT stands for Maximum Power Point Tracking, not Multi Point
+Nicolae Mogoreanu You're right, thanks for catching y mistake. I put a note in the presentation to correct myself.
Wow, this video is almost identical to a video by Australian Direct.
ua-cam.com/video/wmyuxKmlBCk/v-deo.html
Did this example come from a solar controller manufacturer's website, or a sales
Woah, you are right. I wrote the presentation in 2014, picked a random example to use. Theirs is in 2016. So unless time travelling is involved, somebody's got some explaining to do. They do say imitation is a form of flattery....
Well, I think there are a lot of people like me who really appreciate all the time and effort that goes into making these videos. They have really helped me learn enough about solar to get started planning the kind of system I want to install in a few years (as soon as we replace our old roof).
Thanks so much Jess. I just met a woman at the big SPI show in Las Vegas this week. She's in the Middle East, and translates a bunch of our videos into Arabic and records her own version for them to learn. Not for profit, but just to spread knowledge. I thought that was really cool.
This doesn't make any sense. The charge controllers have to overcome the internal resistance of the battery and its voltage in order to charge the battery. Lowering the voltage does not increase the current going into the battery. On the contrary, it will only slow it it down. The formula, I=V/R, expresses is very clearly.
Those things you explained in the video will only work if batteries have no internal resistance. Unfortunately, No such battery exist.
As the MPPT charge controller isolates the solar panel from the battery, it is able to increase the current output capability of the charge controller. With PWM, the panel is just connected straight to the battery with pulses, so any extra power potential is just thrown away. So it's more than just ohm's law at play. You can see us do a demo of it here, ua-cam.com/video/V2b7z2eTb5o/v-deo.html
I've watched the video and also researched more about the topic. I think I understand now how both Charge controllers work. Thanks for clarifying it for me.
Same thing
that is copy
This is not in hindi, please send this video in hindi
I'm sorry, we don't have anyone here able to translate into Hindi.
NOPE!!!! this is a sales add.
Why is pwm charge controller called "PWM"(pulse width modulation) where the is pulse width modulation in pwm charge controller?
Can someone explain that to me ?
Why is pwm charge controller called "PWM"(pulse width modulation) where the is pulse width modulation in pwm charge controller?
Can someone explain that to me ?
I’m not 100% confident, but I believe once the bulk charge stage has occurred and the charger controller is going into “float” mode, because it doesn’t have a DC-DC converter like MPPT does, the only way it can provide smaller currents is to use pulses, where width is the amount of current desired.