Mismatched Solar Panels- Same amps, different volts and watts
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- Опубліковано 27 чер 2016
- www.altestore.com/store/solar...
Here's another of our mismatched solar panel series,. We’ve taken two solar panels, one 24V 100W and one 12V 50W. They both have a current rating of 3 amps. We tested to see which method of wiring them together, series or parallel, works best. We have an MPPT solar charge controller and a 12V battery, with meters measuring the volts in, volts out, and current out. - Наука та технологія
Little "rule of thumb":
When you have multiple different panels,
- if you add them parallel, the voltage will be limited by the lowest
- if you add them serial, the current will be limited by the lowest.
Therefore check which parameter is closer for the panels, and use that configuration.
When currents are pretty similar, use serial (like in this video)
When voltages are similar, use parallel
When you have a wide variety of panels you want to connect into a single system, you can combine parallel/serial connection until you build up a more or less equal system. (more complicated, but can be done)
Of course the characteristics of the panels will be different, therefore the MPPT wont be able to get optimum performance from the system, but it will seek for the maximum possible, and that is close enough.
Thank you so much for explaining these things! I've been searching for these answers for months and you're showing me exactly what i need to do for my situation! Best on youtube!!!!!
The series connection makes so much sense !... great video Amy
i love all of your videos. much more detailed and informative than tbe rest.
these are gr8 video tutorials which I start watching these few days, thanks alot- RAHKAR Green from Afghanistan
Thanks, glad you are enjoying. Let us know if you have any requests.
Great explanation, thanks! Would you be able to test solar panels in series (as per your last test) and then cover up one panel to see if the performance is still ok?
Excellent and professional demo of set up...loving this "series" you are doing! hahaaa!
Thanks Chris, your comments are unparalleled.
Touche! haaha!
How this setup works with 12v panels but 1- 200w; 1-100w with a PWM charge controller, any help will be appreciated, again thanks.
Very clever lady, thanks for this explanation 👌
This helped a lot! Thanks! Would it be too much to combine a 36V 50W panel with a 12V 200W one?
Heard your comment about separate charge controllers for the different panels as an option... how does such an arrangement feed into say a 12v battery bank. I'm a novice.
Thanks for the very informative videos I do like the way you present the data.
Thanks for sharing this information....it's very useful. I have a question, can you charge a single 12v battery with a 300w solar panel with a voltage rating of 36v?
Great series on mixing and matching panels! How about a similar topic with batteries? My RV currently has four US Battery US2200XC2 6 Volt 232Ah Batteries wired series/parallel to make a 12 volt bank. Sadly I don't really have room for more RV (Travel Trailer) mounted batteries. I could add some truck or ground batteries for extra capacity, but do they need to be the same? Could I add 12 volt batteries in parallel with a different Ah rating or do they really need to be matched. even if I bought New matching batteries, they will perform different than this bank of much older batteries that I currently have.
Thanks!
That's really useful, thank you a lot!
I'm enjoying leaning from these test rigs and I always have a go at guessing in advance which arrangement will result in the highest MPPT power output. Really educational videos; thanks Amy (and team)!
I wonder, how does partial shade on one panel affect the overall series performance? If only the voltage drops, not so bad, but if one panel limits the current then it might be worse than if the panels had been wired in parallel.
The shading test could also look at the differences between partial shading on the low voltage vs. high voltage panels. I'm thinking in parallel, if you knew one panel might be in shade occasionally, you'd make that the higher voltage panel.
I love it!!!! Next sunny day, I'll be recording it (we have a stretch of bad weather coming up, then the holiday, give me a week or so). Thanks so much for the suggestion!
I am curious of a side by side comparison to panels wired in series to increase amps and then single panels hooked to multiple charge controllers and the controllers wired in parallel. We know wiring controllers in parallel will increase amps but do you have more loss of efficiency?
Nice explanation...thank you. But the thing that i dont understand is, in series connection, the current should be the lower current of the two sources, whiches 3.08 A, from where we got 8.38 A ?
The lower current panel pulls the whole thing down a bit, but not all the way down.
Very cool Alt E
What will be better in my case is 8 440 watts in series or 9 panels in series-parallel, because 450v is my maximum of inverter panel has a 52 VOC and 4500 wattage
Hi just found you channel. I have 2 /100 watts panels one is 21.8 V the other is 19.83V . My question is ... will this make that much of a difference to no run the parallel. I was told that this might cause my MPPT controller to over charge my batteries
Did you happen to try the series the other way, if you had the neg from the big panel going to the controller instead use the pos?
Because the current travels in a loop, it would hit the bottleneck regardless of the order it travels.
Thanks I have 3 panels 2 100v and 170v all 3 mpv is average 18.5 , amps are 5.41, 5.81, 9.14 amp so series is best ? Running 24v system, 40amp charge controller, battery bank at 24v.
You’ve got a difficult combination. The voltages of all 3 panels are very close, so a parallel configuration would be best. However, your battery is 24 volts, which means in a parallel configuration your solar panels won’t be putting out high enough voltage to charge 24V battery. So a series config will work for you, but you’ll lose a bunch of efficiency because the higher current panel will always drop down to match the lowest current panel in a series configuration. Yes, a series configuration will function with your mismatched panels, but it will not be providing optimum level of power.
love this!! what is the difference between mppt and pwm charge controllers? does it affect battery charging?
We have a whole playlist with many videos about charge controllers. They may help answer any other questions you have. ua-cam.com/play/PLoHd6hGDqS07wkAuvJ_p7_p76tMJRdyYy.html
+altE yes i already watched that video about mppt and pwm charge controllers thanks again for this great video!!
This implies the more panels of any sort you have in series is good. But what about the higher and higher voltage you would get, frying the MPPT charge controller?
Hello, I have a 24v 2.4w solar panel. Can I charge 12 v battery?
A 24V solar panel can charge a 12V battery with an MPPT charge controller. Watch the video we did showing it here, ua-cam.com/video/V2b7z2eTb5o/v-deo.html. Are you sure it's only 2.4 watts, that's a rather odd size for a 24V panel. Perhaps 2.4 amps?
hi Amy, These are the best videos on the net. I have a simple question/request. I have three panels going into a 4 battery bank. panels are old and have been in the sun for years. Could you do a video on how to tell what output your getting from panels without a readable sticker. I need to add a or multiple charge controllers. Thanks in advance for your videos.
Thanks. Great idea. You can check out the video James made many years ago testing a panel. It will give you the open circuit voltage (Voc) and open circuit current (Isc). ua-cam.com/video/fkook28HhWI/v-deo.html
thanks again!
Please condense these findings when you finish the series, and make it available on your website.
You read my mind! I have a few more scenarios to go, then will do a summary. Thanks for the feedback.
I have to say your videos are spectacular, thank you for putting them together! :)
I had a related question, I have two mismatched panels, same Watts (100 each) & same Nominal voltage (12V) though the Vmp/Imp/Voc/Isc are slightly different.
Panel 1) Voc 20V Vmp 16v Isc 6.45A Imp 6.25A
Panel 2) Voc 22.5V Vmp 18.9V Isc 5.74A Imp 5.29A.
The difference is small but wanted an expert opinion as I'm new to solar.
Based on your videos if I have an MPPT controller it seems the best option would be to connect the panels in series so Volts into the MPPT is boosted, the MPPT would lower V out and boost Amps out (12v bank).
Question: what if i used an PWM type controller? I understand if the panels are in series the whole system must be configured for 24V and if in parallel configured for 12V but which would be the best option? If in series would the system be limited to the lowest Imp? and if in parellel would the system be limited to the lowest Vmp?
Any help is appreciated!
Thank you so much, I'm glad you enjoy them. For a system that size, the difference is so small, it won't be noticeable. I would go with the 2 in parallel, and use a PWM.
Wow and you responded almost immediately! :) You guys are awesome. Serious thanks for the videos they are a great educational resource. I'm finishing my BSE in Mechanical Eng. and possible further education in Electrical Eng. I want to apply it to renewable energies, sounds like your team would be a great group to work with!
Hi, can we connect 24v solar panel to 12v battery....suppose if not means why and what is reason?
You can with an MPPT charge controller. The output will drop the voltage and raise the current to keep the same watts and charge the 12V battery. Watch this video, ua-cam.com/video/V2b7z2eTb5o/v-deo.html
What kind of monster actually puts a thumbs down on these videos..
I have 3 solar world 60 cell panels, 290 watt. I want to install 6 canadian solar 315 watt in parallel with the 3 290 watts panels. The voltage, amps are very closely the same. I know that the the system is going to work at the lowest rate, but is any additional info to consider for this combination??
By putting the 2 strings in parallel, you will minimize the losses, as the additional current from the 315s can go around the 290s. The MPPT charge controller will have trouble finding the optimal max power with the two different types going in. You won't get best performance, but it will work.
Thanks for your help
Hey I have a ? If u don't mind
Can I have 1 set of 8 100 watt panels in seires making it 165 volt and 5amps
N other set in parallel making it 40 amps n 20 volt ?
And connect them all together so my battery will charge full ..
I notice my batter keep dying fast since I brought this mpp pip 3024gk . I try having 1 set making it 340 volt n still my battery turn off around 12am.
What is ur take on that ? Thank you for ur time !!!
I believe your inverter will handle all 10 in series in. That is the best way. You should not parallel uneven strings, the lower voltage will suck down the higher voltage and you will lose power.
If you have an existing 12v panel and you want to change it to a 24 volt panel, do you have to change the wires to the charge controller?
Just to clarify, you aren't asking about changing the voltage of one panel from 12 to 24V, because most panels don't let you do that, but are asking if you have a solar array that is wired as 12V, and you switch it to 24V. Charge controllers generally have a PV In+ and a PV In-. AS long as the charge controller is rated for the volts you are putting in, you don't change the connection to it, just connect plus and mins from the solar array to the charge controller. Let me know if that answers your question.
Yes. I would be changing the array. Looks like that's the easiest thing to do. If the existing wiring will take the new 24v panels, that's great. I'd be getting a new mppt controller as well.
Perfect.
no. not if the wire gauge is thick enough to carry the current. the wire can usually carry up to like 600volts. like 10gauge wire can carry like 30amps at 12 24or48 volts.for example. the charge controller may need to be changed. if they are not 24volt comparable.
Which is better having high volts or amps?
I have a mpp solar n right now I get 165 volt in 2 set of 100 watt (16 plane ) 10 amps but if I have 1 set it will make it around 360 volt with 5 amps. My ? Is which is better having high volts . Having them in 2 set or 1
It depends on what your charge controller can handle for voltage input. Most MPPT controllers can't handle 360V input, unless it is a very expensive 600V controller.
@@AltEStore i have mpp solar. It handles 500 volt. I have a ? How much volt do I need to charge 450 amp (I have 4 6v trojan batteries) rem I have 16 of 100 watt solar panels (thats 360 volt ) do I need to add more panels or
If you had 8 300 watt panels wired in parallel facing east and 7 300 watt panels in parallel facing west and the two banks wired in parallel to the charge controller would the bank opposite the sun bring down the bank in the sun
It sounds like all 15 of your panels are wired in parallel…. So the answer to your question is “no”. The currents will simply add in direct proportion to the amount of sunlight they are each receiving. If the east facing panels are no longer receiving direct sun in the evening, they simply stop contributing. They have No effect on the other panels if wired in parallel.
Thank you sir 🙏
Hi Amy,
I have 2 * 265 PC in series 24v system.
I have issue: my MPPT chage controller ( 60A )gives 2 to 4 amp normally in very good day and volt about 26. However when I turn off and ON again then for while it gives high amp to 14 or 16
After half an hr or so it go back to same problem. I bought new MPPT charge controller 60A it behave same way...
What could be the problem?
Are you sure the battery bank isn't full and it is in float mode?
@@AltEStore yes the battery bank was 24.7v on multi meter. It was not fully chage
Please suggest me 250 watt 24 volt pannel 150watt 24 volt pannel joined together series or parller
The same volts but different amps is better in parallel.
do you have any videos for the OUTBACK PSX-240 AUTOTRANSFORMER WITH FAN?
No we don't. Anything in specific you want to see, or just a general overview. I love taking requests.
I have an Aimes 3000 watts/24 v pure sine wave inverter, actually two, not that I can combine them. but any who, I think I can use that transformer to change the 120 vac out to 240 vac to run a well pump, according to the duc you have online. But I might get a out of country 230 vac inverter later an looking for a transformer that would do both.
My transformer theory is a bit rusty.
+Rev John O'Toole I have been thinking of something very similar . maybe just use a 220 230 240volt inverter. and build a transformer to put out two legs of 110-120v. any idea if this would work?
I will work on a video of using a transformer. Until then, you can see the install manual for the transformer here, www.altestore.com/static/datafiles/Others/PSX240%28900-0043-1%29.pdf . It shows that you can connect the 120V from your inverter into the inverter and it will step it up to a 240V output for your 240V loads, like the pump.
I think i have memorized the manual, I called your tech support one day and he told me to call Outback for my questions., but I have figured it out myself. I did mention I'll ask you at some point to get the right answer.
enjoy the hoiliday
Wiring?
How much amps is ok to charge a 200 ah battery?
Lead acid batteries like between 6 and 12 charge rate of their amphours. 200 / 12 = 16A - 33A.
Great vedeo. I will like a video connecting different charge controller into a battery bank. Like a solar panel charge controller and a wind turbine charge controller together. Or 2 solar panel charge controller together.
Your wish is my command. ua-cam.com/video/whFAPTWvWas/v-deo.html
Hi Amy I have 2 miss matched solar panels 1 is 300 watts open circuit voltage 22.32 - short circuit current (A)17.83 -max power voltage 18 - max power current (A) 16.67. second panel max power 175watts - voltage at Pmax 35.2 v - current at Pmax 4.7 A - open circuit voltage 43.6 V - short circuit current 5.48 V if I understand you correctly if I buy 2 separate mppt controllers I can connect the both individual to my caravan batteries and have them produce there max output. cheers Bill
Correct. The 2 are just too different from each other to run on one together. Just connect both controllers to the battery, preferably through a breaker.
Thanks for that quick response Any much appreciated. Is a breaker like a fuse if yes what size would I need for each one. Cheers
How about deferent Imp?
This video discusses same volts, different amps. ua-cam.com/video/P3YtBrymJdA/v-deo.html
still waiting for your mppt with PWM together on same battery bank, Video :(
That one's next, I'm editing it now.
+altE so nice of you
We just released the video you requested. ua-cam.com/video/rBbVIiOBuT4/v-deo.html Sorry about the delay.
+altE Thankyou very much, you are really a solar queen. :)
Can we connect same voltage different watt and amp
You can wire that in parallel.
Oh thank you for that, because I doubt in that set.
is the solar queen still here... need to ask a few queries...
anyone? can you use a 24 volt 300 watt panel with a mppt and a 12 volt bank?
Depending on the MPPT charge controller, yes. Make sure the charge controller can take an input of at least 50V. See our video here where we use an MPPT vs a PWM with a 24V panel and a 12V battery. ua-cam.com/video/V2b7z2eTb5o/v-deo.html
Thank you ! helpful info. Can I use this setup with a 12v power inverter?
If you are charging a 12V battery bank, you can use a 12V inverter.
hello altE
can you please clarify my dought.
If we connect 4 arrays in single mppt/ inverter with 3 arrays at 15 degre angle and 1 array at 25 degre angle.
what will be the losses in that. is that effect a lot to system.
regards
B.K Reddy
It depends on the inverter. If the inverter has multiple MPPT ports, you would be best to put the different tilt in its own MPPT port. IF that is not an option, you will see a change in performance. The amount of the difference would likely be different based on location. You can go to a tool like PVWatts to see the difference of an array at different angles for your area. That may help you get an idea.
It's all right, not alright
Thank you for these videos. However, I am not convinced that these are accurate tests; the battery load and capacity status will vary the load factor.. I would think that for accuracy, one would need to use a dummy load at a fixed nominal load (12v in this case), and then use Ohm's Law to determine wattage produced; A(I) x V = W(p,e). Watts, not current is the key.
I do like that you're testing with MPPT and PWM units as they could vary results; depending on brand, method, component quality, etc. Thx.
Just to clarify further, what if the battery was at 10.5v 0%-capacity, vs the same setup with a battery at 13v 95%-capacity? I think the current out measurement could be quite different, and therefore watts produced very different as well. All constructive comments, btw - not criticizing.
Thanks for your input. We are working on improving our test setups for the upcoming spring. I know I need bigger batteries to help do the tests at a more consistent state of charge. I'm also adding more meters through out the system. Working on continuous improvement. Keep the suggestions coming, we do appreciate them.
Wonderful reply! Thanks for a great progressive attitude and desire to get it right. That's a value statement. Subscribed, and looking forward to more!
Actually, using a dummy load is more inaccurate, as it is not "real world values". You are better-off just using math and base-line values, if you think dummy-load tests are accurate. Those are only good for measuring scales, in controlled labs. We are interested in "reality", not "science experiments".
My car goes 0-60MPH in 2.4 seconds on a dynamo. Put it on the road and it takes 4.5 seconds. Because it has uneven road surfaces, wind, starved air intake and uses the actual car computer to make real-world adjustments. Labs are useless for anything other than knowing how it will behave in a lab.
Max Power Point Transfer. mppt. each panel has a different mppt point. how does a charge controller know at what voltage and amps the mppt should be at if every panel in series is different. answer. it doesn't and most mppt controllers will go into limp mode with this set-up . best off with the less efficient but more suited pwm charge controllers in this case.
There is a reason solar panels are measured in WATTS. Watts is what is important and a much better use of comparison.
Knowing the volts and amps are critical when designing a system, which is why all of the info is given.
nice explanation but the best way is to buy same specifications solar panel while installing solar pv system.
Absolutely. But many people get a mish mash of panels one way or another, and ask us if it makes sense to use them, and if so, how to wire them. So we thought we'd help them figure it out.
Its voc, not it's voc
2 panels with the same (or very similar) Impp are not "mismatched". That is nearly best case scenario for a series connection. This video is misleading. Also, why would you ever connect 2 different voltage panels in parallel? That is just asking for trouble.
People ask us this question all of the time. We decided to show them the answer.
@@AltEStore People are clueless then. Common sense should tell them solar panels are kinda like batteries, they are a source of power. You normally wouldn't (and shouldn't) connect 2 batteries in parallel if they have different voltages (such as a 12V battery and a 6V battery). That is asking for trouble.
In my opinion, the average person should NOT be using solar. They don't have the knowledge to know what to do, especially if something goes wrong. My opinion is the power companies should have big ground mounted solar arrays away from trees, manage them, and beef up the grid to handle the increasing loads. That is the safest way. Look at all the problems people have with solar. Many solar systems cannot be used when the power grid goes down. What a waste! Many people don't want a roomfull of batteries. Too expensive, too much maintenance. Better idea... leave it up to the power companies to use solar and pay your electric bill. I wouldn't want all that crap up on my roof. Some roofs cannot even handle the weight of solar panels. I have seen fires from bad solar installations online. I have seen roofs ripped off (at a school I think) because of a bad installation. Too many problems with solar for the average person. Leave it to the experts (the power companies).
Perhaps in some densely populated areas where there is a lot of sun, solar panels will help take some load off of the grid, but those places are few and far between.
Thank you sexy, intelligent woman! :)
Its the same amount of power you just have not given it anywhere to go
what I mean is the controller is rubbish - so in all intents and purposes your correct
im sorry I've cant follow you at all you are throwing out a million numbers and phrase's and I still don't have the answer .
Short answer: Don't do it.