I don't think shaded panels are a problem, because they usually produce full voltage anyway. Also, night leakage is negligible, since the cells are diodes themselves, with a reverse breakdown voltage of -13V per cell. I think blocking diodes could be useful to prevent a short circuit fault, in a parallel array. You are supposed to put fuses on every panel, in case one decides to take all the 50A of the array through it. Blocking diodes could prevent this, at the cost of 4-5W per string.
I love your explanation....i have a question...the question is some of my solar panels had problems (voltage drop)in each of them(all).finds out the diodes are bad (changed all) while some work and others stil maintain voltage drop... please need your help..thanks from Nigeria.thanks.
I purchased Rich Solar Panels, 190 W. I tested it today using a Watt meter. The day was a clear sunny day, at approximately 12:00 hrs, and the sun at about 80 degrees off the horizon. I had a person angle the solar panel, to try and make it perpendicular to the angle of the sun. I got approximately 111 Watts, 8.5 amps, at 13.5 volts. And when partially shaded by one "Hand" of one person, the current dropped by a factor of 50% from 8.5amps to 4 amps. Under what conditions should I be getting an output of 190 watts? Should I check the diodes, or is there something else that I am doing wrong? I live in Boise, Idaho, and the skys were clear today at approximately 90 degrees outside temperature.
I'm convinced based on what you say here that my cheap USB charging panel does not have a blocking diode. My battery was almost full and leaving it connected overnight, by morning it's almost empty. What is weird is that the USB cable is hooked up to an "input" so I didn't think it possible for reverse current to flow.
I had a back feed of voltage to one of my panels,and it broke two of the four diodes, It is a 12 volt (220 watt) panel, and the voltage read about 4.7 volts. I replaced the two bad diodes and the output voltage is still around 4.7 volts. Do I need to replace all of the diodes ? Any information will be of great help. Thank You.
at a later date,, when i start building my home built micro camper i to tow behind my moped scooter,, i am going to be wanting to order some solar panels. i subscribed to your youtube cannel and i clicked on liked.
Dear altE Store. I have seen some PV systems which use capacitors right after the DC breakers. It is claimed that these capacitors are used to make the fluctuation of the voltage and current from the PV panels to the controller more smooth. Please, explain this to us. Many thanks to your other videos.
+Sufi Shah Hamid Jalali Unlike batteries, capacitors are able to to be charged and discharged very quickly. As a result, some people use high capacitance super capacitors in parallel with their battery bank to basically absorb the voltage spikes from surges from motors, creating a smooth power load. However, a properly sized solar system should not need capacitors. Providing a big enough battery bank that can handle the momentary voltage drop from a surge, and an inverter that is capable of handling the surge, should be enough for most off grid solar systems.
+altE Store, thanks for the quick and great reply. That was useful information. My system is like this click on link: goo.gl/ZsHAVG. If you study the block diagram, there are capacitors between the solar panels and the charge controllers. They are placed right after the DC circuit breakers and DC SPDs.
You have also "ideal diodes modules" on the market that perform as blocking diodes practically without voltage loss. A pair of them is ways cheaper than an additional controler.
This is a well done informative video. Question- looks like I blew the diodes in 2x 100W panels. I am guessing by disconnecting them in full sun or an intermittent short I created when installing a transformer on the load side of my 2x Morningstar SunSaver controllers. Still seems odd as the controllers are full featured and I would have guessed they would protect in this scenario. If I replace the diodes is it possible the panels will still work?
Yes. I admit I have also blown up a diode (wired backwards to a battery without a controller. Don't do that.), and can confirm that replacing them does repair the panel. Hopefully your panel has a junction box that you can get into and just buy a diode and replace it. We have some smaller ones, but they are only big enough for 50W panels. www.altestore.com/store/enclosures-electrical-safety/miscellaneous-electrical-parts/diodes/blocking-diode-for-solar-panels-5a-60v-dc-p196/
Are in night with out solar controller charger solar panel connected directly in this case damages for solar panel or solar panel diodes please inform us or me
Could you do a demonstration of a 2S2P panel configuration with one panel shaded and show what the power out of the charge controller does before and after the panel is partially and fully shaded. My concern is with the Bypass diode when it bypasses the Shaded PV....? Does the power drop ~50% or ~75%?
Very well explained. Thanks alot. Could you maybe make a video for using fuses instead of blocking diodes in the case of shading on parallel PV panels. Thanks again
Can you list bypass and blocking diodes with redundant capacity both amperage and voltage wise…? I plan to combine both fence style and panels that are close to solstice angles in parallel….best example is your sailboat solution. All strings are in 3s and approximately 80 to 100 volts…and between 5 and ten amps…..prefer using ideal style but have no track record on their failure rates….also higher efficiency ones…? Thank you.
Hi Amy, interesting that you bring up the two parallel system issue. I have a 600W wind turbine with a MPPT controller and will be adding the Renogy 600 W 6 panel system with the 60 amp MPPT controller going to the same 12 V battery bank. I would think that with two different MPPT charge controllers running in parallel to the batteries that each would have diodes blocking backflow, thus negating the need for additional blocking diodes. Am I doing the right thing or are there other precautions I should take ? Thanks Jim K RV Prepper
@@AltEStore I meant suppose there are three strings in parallel connected to a common bus. In case one string outputs drop resulting in a drop in output voltage, then what will happen to the other two healthy strings connected to the same bus. Will try to drive power into the impaired one or what will will happen. Please kindly clear my doubt.
Does is matter were i put the solar controle battery wires on the battery bank if its more than one battery in parallel. Also great video learning alot.
Is that a Genasun boost charge controller..? I have a question about the diodes. With a flexible solar panel rated at: 19v, 6.7a, 120w, how many OMS should the diode read if working properly..? (or does it matter how many amps the panel is rated at, do the diodes all read the same when tested..? (How do the amp rating affect reading the multimeter..?
If a panel has bypass diodes in the junction box, why would we have to add a diode to bypass a panel in a series? The internal diodes would provide a current path of the panel for shaded, no?
You mentioned in your video, that it is best to install separete charge controllers for each string of panel, although it is more expensive. What do you mean by that? Do you have a video on this subject? Thanks.
If you have shading on one string and not on the other, you can have them each on their own charge controller so the shaded string doesn't pull down the output of the sunny string. Then wire the outputs of the charge controllers to their own breakers, and to the battery bank. Like in this schematic. i.imgur.com/g3LHozV.jpg
If string a and b are matched in power but string a gets half power due to shade, then even with a diode won’t the total power be brought down in combiner since amperage is suffering?
My solar panel works fine in the morning hours, but falls off dramatically from mid-day on. Typically I will see 15a coming in at 10:30-11am, but around noon it falls down to 1-1.5a. I have checked all wiring, connectors and terminals and everything looks fine. I have one 250w panel connected to a Victron 100/20 MPPT feeding a 200ah LiFePo house bank on my boat. The MPPT was removed and bench tested by a shop and it passed. Do you think I may have bad diodes? Can I test the diodes without removing them from the black box? Thanks.
since glass envelope diodes are allowing uv or sun light to goes through in it and it has a p-n junction,is there way that i can use bunch of glass diodes as a photo voltaic and works like solar cell that procuce voltage?
I currently have this problem. One of the panels connected in parallel to other panels is partially shaded during the day, and as the day progresses the panel that is shaded changes during the course of the day. I thought of using an individual charge controller per panel, but this will not work for several reasons. First, the smallest charge controller that I thought off placing per panel has a higher activation voltage than the maximum voltage per panel. Second, even if the first problem was not an issue, the maximum power point would not be reached, and last but not least the charge controller that I need is part of a group of charge controllers connected as slaves and master. I thought of using optimizers, but the optimizers have an MPPT feature that conflicts with the MPPT of the charge controllers. So, far I have not found an ideal solution for this problem. Any suggestions?
my name is Bobby. my profile picture here is of my girlfriend Patty who she sadly passed away from heart failure about 17 years ago. you did a very great job on your video on blocking diodes. i do have a question i like to ask you,, i understand that a blocking diode lets electricity travel one way but blocks it from going the other way,,,, i do understand that in the blocking mode that the diode blocks most of the electricity but there is a little voltage loss of some electricity passing through,,,,,,, now here is my question,,, could i use 2 diodes or better yet even 3 or even 4 diodes in series and have less of a voltage loss,,, or is that something that by using 2 diodes in series will be a bad idea.
i have a solar panels installed there and recently i have installed hybrid system with generator and now my question is that when there is bright sunshine the solar mppt modules get burned ? so what could be the reason ?
Thank you for your kind and well presented video. Yet, one question begs clarity. When 3 panels are connected in parallel not serial, would a blocking diode or better yet MOSFET on each panel be best to prevent a shaded panel from drawing current from the others ? I only heard you mention it is a good idea for serial panels... but what about parallel panels ?
This statement cotradicts with the presentation. Which one is ccorrect ? Should we need blocking diodes when pannels are parallel ? I am confused. Please explain.
@@samangunasekara8216 Agreed. The sailboat wiring diagram presented shows each solar panel with a blocking diode on the panel output. So, I understand that parallel wired panels that incur partial shading do require blocking diodes.
Hello ma'am, this was quite fruitful but i have a doubt as to where are the charge controllers placed in MW plants as there are no batteries there? And only the bypass diodes are present in the modules and not the blocking ones?
@@AltEStore i have worked in MW plants upto 50mw and the question is as you said there is a possibility that at night the power might flow back to the modules,so what do we do there?
Suggesting i have say 4 panels in series, say 100w 12v, and i wish to add bypass diodes for each, would each need to be rated the same, and how much, and why?
i have two 100w 12v solar panels. each panel has a imax of 5.72A. and diode rating of 12a. and 10A fuse rating. if i wire 3 of these together in parallel to try and create a 300w. 12v panel will they destroy themselves? seeing as how the current together could rise to over 15Amps which is higher than the diode and fuse rating?
+CLIFTON RICARDO RUSSELL If you have more solar panels than can fit in a charge controller, you can add a second charge controller and wire the additional panels to them. Each charge controller would go through its own breaker to the battery bank. There are some charge controllers, like the Midnite Kid, that can be wired together to act like a single bigger charge controller. But most of them would just act independent of each other, each managing its own set of solar panels.
hi, i am make my only solar panel and i want to know how to pick the right blocking diode? i am boosting the voltage from 7.5 to 13.0 volt with a boost converter. and i plan to increase the amperage from .2 Amp to 3.5 Amps. So how do i calculate to get the right diode to charge a 12 volt car battery without a charge controller ?
I'm not sure how you are increasing both the volts and the amps. Also, you shouldn't charge a battery with more than a few watts without a charge controller. You will overcharge the battery. But regardless, if you have 13V x 3.5A = 45 watts. This diode is big enough for up to 50W. www.altestore.com/store/enclosures-electrical-safety/miscellaneous-electrical-parts/diodes/blocking-diode-for-solar-panels-5a-60v-dc-p196/
the regular voltage is 7.5, i increase the voltage to 13 by using a boost converter. i increase the amperage by wiring them in parallel until i reach 3.5 amps.
Ah, I didn't realize you had multiple. Yes, that would increase the current. So I definitely recommend you use a charge controller. That's a lot of power going into a battery with no control.
Hi, do you mind tell how can I charge different type same voltage battery in parallel connected to Hybrid Inverter. when the batteries can also be charged by grid when solar is not enough.
We did a 2 part blog about water pumping, you can read it here, www.altestore.com/blog/2016/05/solar-water-pumps-part-1/ . We also have a playlist of videos with ShurFlo pumps here, ruclips.net/p/PLoHd6hGDqS06tKkfgb9Kq8iP5TaXd0PAi.
If I have (12) 320 watt panels : 4 strings of 3 parallel panels feeding into one charge controller, and half of the panels (the eastern most) receive full sunlight an hour after the western most panels, do you think I should add blocking diodes to the eastern panels to prevent the eastern panels from sucking current before they get light ? ---- your video sort of suggest I should Midnight Classic's string program suggests their Classic 200 will work with this 12 panel configuration- thus my question. I guess the other option is to buy 2 charge controllers and have the western most panels on one, and the eastern most on the other....
The folks at Midnite are incredibly creative, I believe they did put some engineering into their charge controller to help with your situation. If everything seems to be working well, I wouldn't mess with it. I assume you have a 48V battery bank.
Thank you. This is a hypothetical arrangement as the location is perfect for 12 panels, but not as perfect as putting them on a roof (which I can do, but would rather not). I have the panels, just trying to cover all bases before I buy a charge controller, or two. I will check with them. Thank you for your reply.
If you haven't bought the charge controller yet, two that can talk to each other would be your best best. Are the panel 60 or 72 cell? If they are 60 cell, you can use a 150V charge controller with 3 panels in series, no need for the 200V.
They are 72 cell Amy, thus the 200. I've got a 190 foot run to make, so wire size is a concern. Even with 3 panels in series it looks like I need 2 runs of #6 to keep the loss down to 6.5%. I'm using the Vmp (37 volts x 3 =111 volts) in the calculator, as opposed to Voc (46.7 x 3 =140) and 96 amps (8 x 12=96). That's a lot of copper ~!
Cool, just make sure you use at least 200V equipment up to the output of the charge controller. So a Midnite Solar PV6-250 with 250V breakers for the combiner box. You may also want a 60A 600V DC switchgear at the input of the charge controller, like the SquareD HU362RB, www.altestore.com/store/enclosures-electrical-safety/switch-gear-disconnects/switchgear-disconnects-dc/square-d-hu362rb-60a-600v-dc-3-pole-disconnect-switch-nema-3r-p5683/
+anuj kothari A diode won't replace a charge controller. Once the battery is full, the diode won't stop the charging, and you will overcharge and damage your battery. You can use a diode on a very small solar panel, but not on a big one like you have.
Hi..I have a panel output of 150 watt with 8.5 amp approx, also I have diode of 6amp and 3ampCan I use it both in order to save panel from reverse current
+anuj kothari No, neither of those diodes are rated to handle the 8.5A output from the panel. I don't believe you can wire them in parallel to add the amps, you need a higher amp diode. However, with a panel that is outputting 8.5A, that's probably around 140 watts, you should be using a charge controller to protect the battery instead of a diode. The charge controller will protect against backwards flow.
when the cell is shaded, the current drops down, like pinching a garden hose. the cell will have static voltage but reduced current flow. the bypass diode completes the circuit in a loop for the panel. I understand just hard to put into words. If a seller says that these are blocking diodes when they are not, I have to wonder why. and there are many. Thanks
Hi, how can we know if blocking diode is present in the solar panel just by looking at it? I am layman. I have been given a task to identify whether a blocking diode is present in the solar panel or its part.
anuj jain. maybe someone can help. I know when you have a diode in. The panel will drop about half a volt. I have a cheap panel I bought for my car. I am no expert .My way of thinking is if you have a diode installed to prevent leakage your panel would not show charge until it has enough sunlight to allow current to pass. If that theory is true your panel should not show current until it meets the half volt that the diode needs to turn it on. Some diodes turn on at less voltages than that. If you bring the panel in the house and slowly increase the amount of light hitting it using a dimmer switch you should see the diode turn on everytime around .5 of a volt. I think it would be safe to say you should not see a voltage of less than .2 of a volt. As you increase the light the panel should come on at the same amount of light evertime. I am sure someone going to read this and say I am completely wrong and jump in here and help you out.Also I may be completely wrong.I am wrong it could be getting the half volt then showing you the charging voltage on the DMM. This would be easier if I seen the panel. I am sure there is an easy way. It's also been 4 weeks .I would like to know the solution. My solution would be add another diode and allow the half volt loss. It would be easy if the diode is in the supply line.
just checking because the the amps on the battery is high, and how do you what kind of battery do you use because in some battery doesn't show me the amps hour
+Francisco Sanchez Generally, if a battery doesn't tell you the amp hours, and only lists the CCA (cold crank amps), it is not a deep cycle battery, it is a car starter battery and not designed for repeated charge/discharge cycles. A hybrid battery will list both CCA and Ah, and a true deep cycle battery will only list Ah.
Some PV panel manufactures states the bypass diodes that is in their panels. how to select blocking diode for a given panel? for example for a 260W panel
+Musthaq Ahamed I would not recommend using just a blocking diode for such a large panel. You should use a charge controller. But to answer the question specifically, if for some reason you do need a diode, you would select one that is rated to handle the voltage and current rating of the panel. But again, use a charge controller, and you won't need a diode.
Should mention the effect of PV cells shunt leakage. Different PV panels (quality) can have significant difference in shunt leakage of their individual cells. This shunt leakage of PV cells can interfere will ability to make in-circuit testing of bypass diodes. Sometimes it is necessary to unsolder at least one end of diode to check them. Number one failure cause of bypass diodes is excessive heating due to insufficient heat sinking of diodes. Leaded pellet diodes have poor ability to dissipate heat.
+sail1999 You have to find a diode that is rated for the volts and amps of the solar panel. So a 130W panel needs a diode that can handle about 22V and 8 amps.
You said who have quistion ask in comment section so I am asking and hope to find an answer. At 1:39 lets take the diodes , the anode of them is connected to the negative side and their cathode is connected to the positive side !!! so how they will work and pass current (they are now on reverse bias mode)!! you know to put a diode in forward biasing mode the anode should have higher voltage than the cathode!
hi solar queen, want to know plz that can we connect small AND big solar panels With same voltage but different in watt's in series by putting A. by pass diode With small Panel? plz reply thanks
To do that, you need a separate charge controller for each panel. A diode won't help. We did a whole bunch of videos on that, ruclips.net/p/PLoHd6hGDqS04rBGW2bJnDgeEyFKDy2Tpz
hi, i wounder does the diode need to be higher then the battery outputs. i got a solar panel that produces 21 volts and up to 1.3 amps and i wounder do i just need a diode that is litter bit higher than the solar panel or a diode that is higher that the battery?
+Francisco Sanchez The diode needs to be rated to handle the Voc plus temperature deration, so for a 12V panel, at least 26V in cold climates. Here's an example of a diode we sell, www.altestore.com/store/enclosures-electrical-safety/miscellaneous-electrical-parts/diodes/blocking-diode-for-solar-panels-5a-60v-dc-p196/ . It is rated for 60VDC, so it can handle a 24V solar panel.
+Francisco Sanchez The solar panel you have is a 12V nominal solar panel, designed to charge a 12V battery. So as long as the diode can handle 26V, and the battery is a 12V battery bank, you are all set.
This has been the best and most informative piece on blocking and bypass diodes that I have seen, thanks!
Is a blocking diode required for String Combiner Box ?
Outstanding presentation -- particular with reference to partial shading on sailboat applications.
glad someone finally explained what to do to handle shaded panels.
AnantaSesaDas AnantaSesaDas I know right
I don't think shaded panels are a problem, because they usually produce full voltage anyway. Also, night leakage is negligible, since the cells are diodes themselves, with a reverse breakdown voltage of -13V per cell.
I think blocking diodes could be useful to prevent a short circuit fault, in a parallel array. You are supposed to put fuses on every panel, in case one decides to take all the 50A of the array through it. Blocking diodes could prevent this, at the cost of 4-5W per string.
I've been thinking and guessing a lot of things about solar panels and diodes, I'm glad I found this video confirming my ideas, thanks !
Math Math Math knowledge is power.
Nicely presented and clearly communicated - thanks
I agree with the above statement. Great job.
Thank you for the explanation
Best channel to understand solar panels
Thank you very much, i have some homemade panels an this was very concise and informative on the use of diodes!!!!
Very good lecture. Thank you so much for your time and knowledge
A lot of great info in a very digestible package. Many Thanks!
Good. Finally got some good video giving plain reasoning and avoiding "information bombardment"
This video help me out a lot I am a student becoming an electrician thank you
very good stuff, straight forward . Best way to say anything.
Thanks, idea communicated in a proper way.
I love your explanation....i have a question...the question is some of my solar panels had problems (voltage drop)in each of them(all).finds out the diodes are bad (changed all) while some work and others stil maintain voltage drop... please need your help..thanks from Nigeria.thanks.
From Paklistan ...great thnx
I purchased Rich Solar Panels, 190 W. I tested it today using a Watt meter. The day was a clear sunny day, at approximately 12:00 hrs, and the sun at about 80 degrees off the horizon. I had a person angle the solar panel, to try and make it perpendicular to the angle of the sun. I got approximately 111 Watts, 8.5 amps, at 13.5 volts. And when partially shaded by one "Hand" of one person, the current dropped by a factor of 50% from 8.5amps to 4 amps. Under what conditions should I be getting an output of 190 watts? Should I check the diodes, or is there something else that I am doing wrong? I live in Boise, Idaho, and the skys were clear today at approximately 90 degrees outside temperature.
I'm convinced based on what you say here that my cheap USB charging panel does not have a blocking diode. My battery was almost full and leaving it connected overnight, by morning it's almost empty. What is weird is that the USB cable is hooked up to an "input" so I didn't think it possible for reverse current to flow.
I need a Renewable Doable Coffee Mug! With your AltE logo on the other side!
Always informative..thanks for this Alt-e.
I had a back feed of voltage to one of my panels,and it broke two of the four diodes, It is a 12 volt (220 watt) panel, and the voltage read about 4.7 volts. I replaced the two bad diodes and the output voltage is still around 4.7 volts. Do I need to replace all of the diodes ? Any information will be of great help. Thank You.
Excellent info. Thanks, 2 thumbs up.
at a later date,, when i start building my home built micro camper i to tow behind my moped scooter,, i am going to be wanting to order some solar panels. i subscribed to your youtube cannel and i clicked on liked.
Dear altE Store. I have seen some PV systems which use capacitors right after the DC breakers. It is claimed that these capacitors are used to make the fluctuation of the voltage and current from the PV panels to the controller more smooth. Please, explain this to us. Many thanks to your other videos.
+Sufi Shah Hamid Jalali Unlike batteries, capacitors are able to to be charged and discharged very quickly. As a result, some people use high capacitance super capacitors in parallel with their battery bank to basically absorb the voltage spikes from surges from motors, creating a smooth power load. However, a properly sized solar system should not need capacitors. Providing a big enough battery bank that can handle the momentary voltage drop from a surge, and an inverter that is capable of handling the surge, should be enough for most off grid solar systems.
+altE Store, thanks for the quick and great reply. That was useful information. My system is like this click on link: goo.gl/ZsHAVG. If you study the block diagram, there are capacitors between the solar panels and the charge controllers. They are placed right after the DC circuit breakers and DC SPDs.
You have also "ideal diodes modules" on the market that perform as blocking diodes practically without voltage loss.
A pair of them is ways cheaper than an additional controler.
This is a well done informative video.
Question- looks like I blew the diodes in 2x 100W panels. I am guessing by disconnecting them in full sun or an intermittent short I created when installing a transformer on the load side of my 2x Morningstar SunSaver controllers. Still seems odd as the controllers are full featured and I would have guessed they would protect in this scenario.
If I replace the diodes is it possible the panels will still work?
Yes. I admit I have also blown up a diode (wired backwards to a battery without a controller. Don't do that.), and can confirm that replacing them does repair the panel. Hopefully your panel has a junction box that you can get into and just buy a diode and replace it. We have some smaller ones, but they are only big enough for 50W panels. www.altestore.com/store/enclosures-electrical-safety/miscellaneous-electrical-parts/diodes/blocking-diode-for-solar-panels-5a-60v-dc-p196/
Clifford Novey Clifford great question
Thanks for the info. What are the pros vs cons on solar panels configured in Series vs Parallel for a 12v system?
What a great video.i am a big follower of your's.thanks mam for your information... thanks allot
Are in night with out solar controller charger solar panel connected directly in this case damages for solar panel or solar panel diodes please inform us or me
Could you do a demonstration of a 2S2P panel configuration with one panel shaded and show what the power out of the charge controller does before and after the panel is partially and fully shaded. My concern is with the Bypass diode when it bypasses the Shaded PV....? Does the power drop ~50% or ~75%?
Very well explained. Thanks alot. Could you maybe make a video for using fuses instead of blocking diodes in the case of shading on parallel PV panels. Thanks again
Nicely explained.
Absolutely easy explaination
Can you list bypass and blocking diodes with redundant capacity both amperage and voltage wise…?
I plan to combine both fence style and panels that are close to solstice angles in parallel….best example is your sailboat solution.
All strings are in 3s and approximately 80 to 100 volts…and between 5 and ten amps…..prefer using ideal style but have no track record on their failure rates….also higher efficiency ones…?
Thank you.
Hi Amy, interesting that you bring up the two parallel system issue. I have a 600W wind turbine with a MPPT controller and will be adding the Renogy 600 W 6 panel system with the 60 amp MPPT controller going to the same 12 V battery bank. I would think that with two different MPPT charge controllers running in parallel to the batteries that each would have diodes blocking backflow, thus negating the need for additional blocking diodes. Am I doing the right thing or are there other precautions I should take ? Thanks Jim K RV Prepper
Since the turbine will have its own controller, you should be fine. It's more of an issue when the turbine doesn't have a controller.
James Krivitsky James awesome question & solution.
Gr8 video
Would a blocking diode be required for each parallel string connected to a string combiner box ?
In a combiner box, you will usually have breakers or fuses connected to common bus bars.
@@AltEStore I meant suppose there are three strings in parallel connected to a common bus. In case one string outputs drop resulting in a drop in output voltage, then what will happen to the other two healthy strings connected to the same bus. Will try to drive power into the impaired one or what will will happen.
Please kindly clear my doubt.
Does is matter were i put the solar controle battery wires on the battery bank if its more than one battery in parallel. Also great video learning alot.
I've been losing power from my battery even though I have a charge controller. Where should I put my blocking diode?
Thanks for the diode class.
Does it matter if the panel doesn't have any diode?
Since my diodes are broken and I seemed to be difficult to find new one
Is that a Genasun boost charge controller..? I have a question about the diodes. With a flexible solar panel rated at: 19v, 6.7a, 120w, how many OMS should the diode read if working properly..? (or does it matter how many amps the panel is rated at, do the diodes all read the same when tested..? (How do the amp rating affect reading the multimeter..?
Thanks for the information!
If a panel has bypass diodes in the junction box, why would we have to add a diode to bypass a panel in a series? The internal diodes would provide a current path of the panel for shaded, no?
You mentioned in your video, that it is best to install separete charge controllers for each string of panel, although it is more expensive. What do you mean by that? Do you have a video on this subject? Thanks.
If you have shading on one string and not on the other, you can have them each on their own charge controller so the shaded string doesn't pull down the output of the sunny string. Then wire the outputs of the charge controllers to their own breakers, and to the battery bank. Like in this schematic. i.imgur.com/g3LHozV.jpg
If string a and b are matched in power but string a gets half power due to shade, then even with a diode won’t the total power be brought down in combiner since amperage is suffering?
May I ask what is the cause of reversing error on the scc during night, the connection of the panel is series, thanks
very help full with many thanks
I have a 265 watt 8 Amp what type of bypass diodes i need? .can i buy a 15 Amp bybass diode or 10 amp by diode.
My solar panel works fine in the morning hours, but falls off dramatically from mid-day on. Typically I will see 15a coming in at 10:30-11am, but around noon it falls down to 1-1.5a. I have checked all wiring, connectors and terminals and everything looks fine. I have one 250w panel connected to a Victron 100/20 MPPT feeding a 200ah LiFePo house bank on my boat. The MPPT was removed and bench tested by a shop and it passed. Do you think I may have bad diodes? Can I test the diodes without removing them from the black box? Thanks.
since glass envelope diodes are allowing uv or sun light to goes through in it and it has a p-n junction,is there way that i can use bunch of glass diodes as a photo voltaic and works like solar cell that procuce voltage?
I currently have this problem. One of the panels connected in parallel to other panels is partially shaded during the day, and as the day progresses the panel that is shaded changes during the course of the day. I thought of using an individual charge controller per panel, but this will not work for several reasons.
First, the smallest charge controller that I thought off placing per panel has a higher activation voltage than the maximum voltage per panel.
Second, even if the first problem was not an issue, the maximum power point would not be reached, and last but not least the charge controller that I need is part of a group of charge controllers connected as slaves and master.
I thought of using optimizers, but the optimizers have an MPPT feature that conflicts with the MPPT of the charge controllers. So, far I have not found an ideal solution for this problem. Any suggestions?
my name is Bobby. my profile picture here is of my girlfriend Patty who she sadly passed away from heart failure about 17 years ago. you did a very great job on your video on blocking diodes. i do have a question i like to ask you,, i understand that a blocking diode lets electricity travel one way but blocks it from going the other way,,,, i do understand that in the blocking mode that the diode blocks most of the electricity but there is a little voltage loss of some electricity passing through,,,,,,, now here is my question,,, could i use 2 diodes or better yet even 3 or even 4 diodes in series and have less of a voltage loss,,, or is that something that by using 2 diodes in series will be a bad idea.
The voltage drop across each diode would be additive, so multiple diodes in series would increase the amount of voltage lost.
i have a solar panels installed there and recently i have installed hybrid system with generator and now my question is that when there is bright sunshine the solar mppt modules get burned ? so what could be the reason ?
Thank you for your kind and well presented video. Yet, one question begs clarity. When 3 panels are connected in parallel not serial, would a blocking diode or better yet MOSFET on each panel be best to prevent a shaded panel from drawing current from the others ? I only heard you mention it is a good idea for serial panels... but what about parallel panels ?
Since parallel panels have a complete circuit around the shaded panel, a diode isn't generally needed.
This statement cotradicts with the presentation. Which one is ccorrect ? Should we need blocking diodes when pannels are parallel ? I am confused. Please explain.
@@samangunasekara8216 Agreed. The sailboat wiring diagram presented shows each solar panel with a blocking diode on the panel output. So, I understand that parallel wired panels that incur partial shading do require blocking diodes.
how do i know if my charge controller has a blocking diode
Hello ma'am, this was quite fruitful but i have a doubt as to where are the charge controllers placed in MW plants as there are no batteries there? And only the bypass diodes are present in the modules and not the blocking ones?
Grid tied systems are very different. The panels connect to an inverter which converts the DC power to AC. No diodes are needed.
@@AltEStore i have worked in MW plants upto 50mw and the question is as you said there is a possibility that at night the power might flow back to the modules,so what do we do there?
@@ashishmahajan7223 the inverter prevents back feeding. No diodes are needed.
@@AltEStore okay thank you very much
Is that become basic in all panels
Suggesting i have say 4 panels in series, say 100w 12v, and i wish to add bypass diodes for each, would each need to be rated the same, and how much, and why?
Perfect video
i have two 100w 12v solar panels. each panel has a imax of 5.72A. and diode rating of 12a. and 10A fuse rating. if i wire 3 of these together in parallel to try and create a 300w. 12v panel will they destroy themselves? seeing as how the current together could rise to over 15Amps which is higher than the diode and fuse rating?
Thanks again for the info,can you connect two charge controller together to increase the amps?
+CLIFTON RICARDO RUSSELL If you have more solar panels than can fit in a charge controller, you can add a second charge controller and wire the additional panels to them. Each charge controller would go through its own breaker to the battery bank. There are some charge controllers, like the Midnite Kid, that can be wired together to act like a single bigger charge controller. But most of them would just act independent of each other, each managing its own set of solar panels.
+altE Store understand it better now,cheers
How to check a 50A diode without multimeter?
in a nutshell, for efficiency of panel then i should remove the diodes and run all panels through charge controller ?
No. Leave the diode alone.
hi, i am make my only solar panel and i want to know how to pick the right blocking diode? i am boosting the voltage from 7.5 to 13.0 volt with a boost converter. and i plan to increase the amperage from .2 Amp to 3.5 Amps. So how do i calculate to get the right diode to charge a 12 volt car battery without a charge controller ?
I'm not sure how you are increasing both the volts and the amps. Also, you shouldn't charge a battery with more than a few watts without a charge controller. You will overcharge the battery.
But regardless, if you have 13V x 3.5A = 45 watts. This diode is big enough for up to 50W. www.altestore.com/store/enclosures-electrical-safety/miscellaneous-electrical-parts/diodes/blocking-diode-for-solar-panels-5a-60v-dc-p196/
the regular voltage is 7.5, i increase the voltage to 13 by using a boost converter. i increase the amperage by wiring them in parallel until i reach 3.5 amps.
Ah, I didn't realize you had multiple. Yes, that would increase the current. So I definitely recommend you use a charge controller. That's a lot of power going into a battery with no control.
i just want to have an emergency charger that will be protected the solar panel but also charge the battery, i can watch it to see how is doing.
Could you please state the increased module efficiency in using by pass module?
Thanks for the information bout diodes
Hi, do you mind tell how can I charge different type same voltage battery in parallel connected to Hybrid Inverter. when the batteries can also be charged by grid when solar is not enough.
whats the best bypass diode dor a 50w solar panel 3.19amp?
Please explain about batteries set points along with graphical representation
Please advice on using solar panels to pump water
We did a 2 part blog about water pumping, you can read it here, www.altestore.com/blog/2016/05/solar-water-pumps-part-1/ . We also have a playlist of videos with ShurFlo pumps here, ruclips.net/p/PLoHd6hGDqS06tKkfgb9Kq8iP5TaXd0PAi.
The bypass and blocking diodes used in PV are photo diodes ?
Schottky diodes
The most excellent explanation. Thank you.
thank,s
I am from pakistan .You have given good information .if we Do not use Solar Controller then How do we apply a blocking dioad With solar penal.
If I have (12) 320 watt panels : 4 strings of 3 parallel panels feeding into one charge controller, and half of the panels (the eastern most) receive full sunlight an hour after the western most panels, do you think I should add blocking diodes to the eastern panels to prevent the eastern panels from sucking current before they get light ? ---- your video sort of suggest I should
Midnight Classic's string program suggests their Classic 200 will work with this 12 panel configuration- thus my question.
I guess the other option is to buy 2 charge controllers and have the western most panels on one, and the eastern most on the other....
The folks at Midnite are incredibly creative, I believe they did put some engineering into their charge controller to help with your situation. If everything seems to be working well, I wouldn't mess with it. I assume you have a 48V battery bank.
Thank you. This is a hypothetical arrangement as the location is perfect for 12 panels, but not as perfect as putting them on a roof (which I can do, but would rather not). I have the panels, just trying to cover all bases before I buy a charge controller, or two. I will check with them. Thank you for your reply.
If you haven't bought the charge controller yet, two that can talk to each other would be your best best. Are the panel 60 or 72 cell? If they are 60 cell, you can use a 150V charge controller with 3 panels in series, no need for the 200V.
They are 72 cell Amy, thus the 200. I've got a 190 foot run to make, so wire size is a concern. Even with 3 panels in series it looks like I need 2 runs of #6 to keep the loss down to 6.5%. I'm using the Vmp (37 volts x 3 =111 volts) in the calculator, as opposed to Voc (46.7 x 3 =140) and 96 amps (8 x 12=96). That's a lot of copper ~!
Cool, just make sure you use at least 200V equipment up to the output of the charge controller. So a Midnite Solar PV6-250 with 250V breakers for the combiner box. You may also want a 60A 600V DC switchgear at the input of the charge controller, like the SquareD HU362RB, www.altestore.com/store/enclosures-electrical-safety/switch-gear-disconnects/switchgear-disconnects-dc/square-d-hu362rb-60a-600v-dc-3-pole-disconnect-switch-nema-3r-p5683/
Great vid Amy
In case of grid connected PV system, what might be security for backflow of higher grid voltages to inverter?
The inverter itself takes care of all of that, no need to worry about it.
I have a Newpowa 70 watt panel that only has 1 diode in it. Can anyone give me an answer as to what Schottky diode I need to replace it with?
Instead can we use 2 diodes of 6amp and connected in parallel...will that be safe enough...
+anuj kothari A diode won't replace a charge controller. Once the battery is full, the diode won't stop the charging, and you will overcharge and damage your battery. You can use a diode on a very small solar panel, but not on a big one like you have.
Hi..I have a panel output of 150 watt with 8.5 amp approx, also I have diode of 6amp and 3ampCan I use it both in order to save panel from reverse current
+anuj kothari No, neither of those diodes are rated to handle the 8.5A output from the panel. I don't believe you can wire them in parallel to add the amps, you need a higher amp diode. However, with a panel that is outputting 8.5A, that's probably around 140 watts, you should be using a charge controller to protect the battery instead of a diode. The charge controller will protect against backwards flow.
very
very
help full
Clearly explained 😅😊😊😊
Specifications of blocking and bypass diodes?
Can solar panel run with out diode is I already got the regular charge?
There are very few times when you actually need a diode. If you have a charge controller, you are all set.
Tq ma'am beautifully explained.
when the cell is shaded, the current drops down, like pinching a garden hose. the cell will have static voltage but reduced current flow. the bypass diode completes the circuit in a loop for the panel. I understand just hard to put into words.
If a seller says that these are blocking diodes when they are not, I have to wonder why. and there are many.
Thanks
+Rev John O'Toole I love the garden hose analogy, well done. I may need to borrow that.
Many thanks for the informative videos , please tell us about pvsyst software tutorial?
Hi, how can we know if blocking diode is present in the solar panel just by looking at it? I am layman. I have been given a task to identify whether a blocking diode is present in the solar panel or its part.
anuj jain. maybe someone can help. I know when you have a diode in. The panel will drop about half a volt. I have a cheap panel I bought for my car. I am no expert .My way of thinking is if you have a diode installed to prevent leakage your panel would not show charge until it has enough sunlight to allow current to pass. If that theory is true your panel should not show current until it meets the half volt that the diode needs to turn it on. Some diodes turn on at less voltages than that. If you bring the panel in the house and slowly increase the amount of light hitting it using a dimmer switch you should see the diode turn on everytime around .5 of a volt. I think it would be safe to say you should not see a voltage of less than .2 of a volt. As you increase the light the panel should come on at the same amount of light evertime. I am sure someone going to read this and say I am completely wrong and jump in here and help you out.Also I may be completely wrong.I am wrong it could be getting the half volt then showing you the charging voltage on the DMM. This would be easier if I seen the panel. I am sure there is an easy way. It's also been 4 weeks .I would like to know the solution. My solution would be add another diode and allow the half volt loss. It would be easy if the diode is in the supply line.
anuj jain anuj great question
Hello! do you have any videos on which kind of bypass diode(Amps/Volt) to be connected in parallel with series of solar cell (Amps/Volt)
It's usually a schottky diode, and the volts and amps would be based on the volts and amps of the solar panels.
@@AltEStore Could you please state the increased module efficiency in using by pass module?
just checking because the the amps on the battery is high, and how do you what kind of battery do you use because in some battery doesn't show me the amps hour
+Francisco Sanchez Generally, if a battery doesn't tell you the amp hours, and only lists the CCA (cold crank amps), it is not a deep cycle battery, it is a car starter battery and not designed for repeated charge/discharge cycles. A hybrid battery will list both CCA and Ah, and a true deep cycle battery will only list Ah.
Some PV panel manufactures states the bypass diodes that is in their panels. how to select blocking diode for a given panel?
for example for a 260W panel
+Musthaq Ahamed I would not recommend using just a blocking diode for such a large panel. You should use a charge controller. But to answer the question specifically, if for some reason you do need a diode, you would select one that is rated to handle the voltage and current rating of the panel. But again, use a charge controller, and you won't need a diode.
Should mention the effect of PV cells shunt leakage. Different PV panels (quality) can have significant difference in shunt leakage of their individual cells. This shunt leakage of PV cells can interfere will ability to make in-circuit testing of bypass diodes. Sometimes it is necessary to unsolder at least one end of diode to check them.
Number one failure cause of bypass diodes is excessive heating due to insufficient heat sinking of diodes. Leaded pellet diodes have poor ability to dissipate heat.
MUITO BOA EXPLICAÇÃO.
AMY YOU ARE GREAT
Does one size diode fit all solar panels? If not what size for a 130 watt panel?
+sail1999 You have to find a diode that is rated for the volts and amps of the solar panel. So a 130W panel needs a diode that can handle about 22V and 8 amps.
Thanks
You said who have quistion ask in comment section so I am asking and hope to find an answer.
At 1:39 lets take the diodes , the anode of them is connected to the negative side and their cathode is connected to the positive side !!! so how they will work and pass current (they are now on reverse bias mode)!! you know to put a diode in forward biasing mode the anode should have higher voltage than the cathode!
Awesome thank you so much!
Do I need diodes when panels are connected in parallel and one of the panel often sees shade?
We talk about that at 3:06. A diode in series with the panels may be useful.
@@AltEStore yes, thanks a lot.
hi solar queen, want to know plz that can we connect small AND big solar panels With same voltage but different in watt's in series by putting A. by pass diode With small Panel? plz reply thanks
To do that, you need a separate charge controller for each panel. A diode won't help. We did a whole bunch of videos on that, ruclips.net/p/PLoHd6hGDqS04rBGW2bJnDgeEyFKDy2Tpz
altE thank-you
hi, i wounder does the diode need to be higher then the battery outputs. i got a solar panel that produces 21 volts and up to 1.3 amps and i wounder do i just need a diode that is litter bit higher than the solar panel or a diode that is higher that the battery?
+Francisco Sanchez The diode needs to be rated to handle the Voc plus temperature deration, so for a 12V panel, at least 26V in cold climates. Here's an example of a diode we sell, www.altestore.com/store/enclosures-electrical-safety/miscellaneous-electrical-parts/diodes/blocking-diode-for-solar-panels-5a-60v-dc-p196/ . It is rated for 60VDC, so it can handle a 24V solar panel.
How about the battery
+Francisco Sanchez The solar panel you have is a 12V nominal solar panel, designed to charge a 12V battery. So as long as the diode can handle 26V, and the battery is a 12V battery bank, you are all set.
but still rechargeable right