This panel can put out close to 100 watts ru-vid.comUgkxOqI2yqX0XVrhR2BMJciTWrHJpG8FhJyg when positioned in the appropriate southernly direction, tilted to the optimal angle for your latitude/date, and connected to a higher capacity device than a 500. The built in kickstand angle is a fixed at 50 degrees. Up to 20% more power can be output by selecting the actual date and latitude optimal angle.The 500 will only input 3.5A maximum at 18 volts for 63 watts. Some of the excess power from the panel can be fed into a USB battery bank, charged directly from the panel while also charging a 500. This will allow you to harvest as much as 63 + 15 = 78 watts.If this panel is used to charge a larger device, such as the power station, then its full output potential can be realized.
A barrel and pin system would be super easy for this and probably very sturdy. Could even potentially incorporate the cell connections into the barrels and connect via the pin.
@@addygreen8919 maybe it's because it is more versatile because you can change certain features at your own accord unlike the commercial product where it's difficult to edit to meet your needs. Besides this is an early prototype so he might be able to reduce the cost or improve the product in a later video.
The solar tapping wires are going to wear out and break within a few folds, wouldn't they? An MPPT circuit would be a more proper solution than the buck boost converter, maybe try to make a DIY low power MPPT circuit for next project?
MPPT would require a load that can absorb a continually variable amount of power. I don't know if all phones would accept a varying power input. This is why in general a battery or supercapacitor is used as an intermediary buffer. Something like USB Power Delivery or one of the proprietary Quick Charge standards might help.
The dodgy wiring can be easily fixed a number of ways. So in my opinion feels largely unimportant just couldnt be bothered to do it properly because its rapid prototyping. Perhaps that should have been stated more clearly when mentioned. Anyhow more importantly I think the other issue you raise here about MPPT is indeed something that should be addressed and looked into further. I was actually pretty impressed however at how well matched and good performance he managed to get with the off the shelf cheapo buck boost converter. So maybe a good follow up would be a head to head contest between that and a cheap MPPT (or self made one). To see how much benefit for doing it properly. Vs the higher cost of that component. And to see how much power was actually being left on the table. And perhaps gain some useful insight as to why the specific buck boost converter being chosen had worked so well as it did. If it was anything to do with the input stage of the buck boost circuit being in common with the way an MPPT works. Would be great part 2 revisit.. I also wanted to point out that epoxy shrinks by 10% so is not ideal for larger panels that you can see in the video does not dry flat due to the shrinkage or may cause stress or other mechanical issue. And of course 3ed prints are not exactly the stiffest backing material either. So investigating a better protective covering / housing materials would also be worthwhile. If somebody else is trying to repeat this project. I am personally not sure what would be most suitable because there are a number of different options. Which will have different sets of pros / cons. And cost different amounts since this is a budget sensitive project. Just try to avoid the epoxy (if you can find something else better)n is just my main point here, because your standard epoxy will always shrink.
I'd also add atlsast one schotky diode to prevent backflow into the cells, commercially available panels come with one diode per panel but that's probably overkill for something like this.
@@frogjmon unlike an inductive load like a motor, the schotky Diodes in PV-Modules serve to prevent single shaded or broken cells from running in reverse breakdown, which happens in Strings of round about 24 cells (24 * V_forward > 1 * V_revbreakdown. Only applies to crystalline cells.
Did you perform the Current Load Test of 10:00 on the commercial product? If the current was limited by your phone, then the maximum current capabilities would be higher too, right?
bro he means direct 2 wire system system of 5v charging is limited . by the way we only get 2.4 A max technology for fast charging on 2 wired ampere technology we need data line for increased voltage rather than current for fast charging . some phone go up to 18V+ for fast charging so wire is be thin for more power . and charge pull more to battery.
@@greatscottlab Then how did the commercial version loose? Not to mention durability... Those tabs going to hold up to repeated folding and unfolding? I doubt it.
@@greatscottlab Isc only applies in STC = standard test conditions = laboratory conditions of 1000 W/m² and 25°C cell temperature. You would at least need to direct the cells to the sun to get closer to the nominal Isc and Voc I would love to invite you to our research center, Fraunhofer Center for Silicon-Photovoltaics in Halle.
I've made a similar solar charger using 10 solar panels(89 mm x 145 mm for each panel) and a 5v usb converter, and output current was about 1,5 amps in mid day (between 11:00 and 16:00). My solution for hinge mechanism was to use duct tape, it wasn't beautiful but functional. Duct tape can be used for both fabric and hinge use, if anyone is interested I can share the pictures.
@ScrotNimation I seriously considered buying a sewing machine, but duct tape was a short term solution. I had a 1 week bicycle tour coming in a short time, and went for the quick&dirty solution :)
@@williamlivingston2929 I will definetly shoot a video for that, currently waiting for the aliexpress shipments. My friend "confisticaded" my solar panels:)
@@greatscottlab you are too humble. shorten up the taping leads and use small copper braid... Doesn't even need to be insulated and could run uninsulated in the fabric hinges--which are a great idea themselves. I would rubberize one side of the fabric (or use a rubberized or some type of water resistant cushioned fabric) to help with moisture resistance. That's already a pretty big set of cells.
Cells are tested in labs under 1200 watt bulbs at 25°C, reason for the "wrong" readings. Plus, the epoxy can get opaque and yellowish with time if it's not UV resistant and can't hold the stress of time as it would probably get darker before the panel begins to wear out (if it's under a constant exposure). Should be good for the usage you have in mind though.
And dont forget the angle of cell vs. Sun Unless your garden is located at terrestrial Equator you should tilt your cell according the Sun angle, which depends on latitude, day in year and local suntime Next proyect could be an automatic two-axis positioner with those factors in mind
The problem I had with epoxy was the expansion and contraction was breaking my cells. That was when I tried to encapsulate them to glass. I think it is better to encapsulate each cell individually. Good Job!
I only have 1 quick solution that seems to work against the yellowing stuff. Most of those cheap garden lights use those yellowing cells which become useless after a couple of months. I also have a 6V panel that is covered in epoxy and the same thing happened. Sanded all of them to make them ok again but same thing yellowing started again after a month or so. Now I cover them with helicopter tape. The stuff they use to for example protect bike frames. You can get that stuff for a couple of euro. I just cut it and stick it over the cell after I make it clear again. If I now buy new solar stuff which uses those cell I immediately stick it on. The 6V cell is still clear now like all of my other 'toys' after being 3 years in the elements. I might replace the aging tape next year but that is just a 5 minute job.
This is why this plastic crap never lasts in the long run even if it is UV stable there is always mechanical wear and scratching from normal uses that does them in. I always preferred rigid panels with all this in mind.
if you are doing a protable solar panel, I would suggest using Maxeon C60 flexible cells. The cells you are using are more suitable for fixed panels (with tempered glass). Also in order to harvest maximum energy output of the cell you need to keep it in the most efficient voltage range. Mppt chatger would be a better option instead of buck boost converter. Last thing is I don't think the cells you are using have any problem, I wouldn't expect you to get more than half of its rated power in germany without pointing the cell directly towards sun. 4.2W output is measured only in 1000w/m2 irradiance with cell pointed directly to sun.
On plain USB 5V, most phones limit the charging current to way below 2A. You saw it when you connected the buck/boost converter to your power supply and it was still only charging with 1.4A. But things change with QC (9V 1.8A) or even USB-C PD (5V 3A). Always test with an empty phone battery. The phone limits the charging to below 5W when the battery reaches 80%++
That is really awesome. I also would love to see a MPPT-Circuit explained from you. And a question remaines, how heavily was the Current influenced by laying the Panels flat to the Table? Maybe they got that rating by facing the panel directly to the sun?
GreatScott I had developed that module for my mobile in my engineering college as a mini project but I had used single solar panel of 7 volt and 2 amp and used a Linear regulator lm7805. It was good and fun.
My mom brought home broken solar night lights from work so i built origami style one It was great to charge my old phone but school bullies smashed it I guess they don't like renewable energy sources
@@sarimbinwaseem karma struck back hard on them One came crawling to my house (broke, unwashed, smelling like death) to ask if my car is still on sale I did the ultimate sike on him
I've also tried to make a portable solar charger some time ago using small 5V epoxy coated solar cells. I tried to reuse an old solar charger enclosure, as its electronic components were mounted on a separate part, which could easily be slipped out, but not salvaged nor repaired- it was all coated in resin (which, I must say, made it very durable, but not until the charging circuitry and battery worn out). I encountered the same problem as you did (specs far lower than advertised), so I would get a maximum of 2 watts of power, while the original charger had somewhere around 5 watts - and it was older tech, so still impressive for such a small form factor. I think that without some built-in energy storage like a supercapacitor or battery using the solar cells alone for power is rather unstable, and adding that would allow to trickle charge even during overcast or winter conditions.
I'm a DJ and have turntables, my initial thoughts of you spreading the epoxy was to pour it on and have something spin the cell slowly to spread it out but if the epoxy hardened slowly, it'll even itself out eventually unless super viscous.
Hello! I really love your channel GreatScott! I have decided to ask a question here because You seem like a professional, and everyone, feel free to answer is question I have been wondering. How are current and voltage different, and does voltage create current. This is been a question that online websites cannot answer. Thank You
Current is the flow of charged partials such as electrons. Voltage is the force that pushes the charged partials. Electrons will only flow if there is some force pushing them. This means that current will only flow through something if there is a voltage across it that pushes the current through it. For more details I highly recommend watching ElectroBoom's 101 series.
Another way to think of voltage and current is an analogy with flowing water, where voltage is the amount of water, and current is, well, current (speed/power of the flow)! For example, think of a very wide, but very shallow river - this is the equivalent of high voltage with low current, like electrostatic discharge (the zap you get when when you touch your car's chassis in the winter, or after scuffing your feet on a rug), which typically measures in excess of 3,000 volts, and often as much as 20,000-30,000 volts, but at *very* low current. The shallow river, although composed of lots of water, will not sweep you off your feet :)
Would be cool if you would do an episode of DIY or buy MPPT's and hook your own MPPT to these cells. I have always been interested in how MPPT's could been made and what results you could expect.
The hinges was what i didnt get when you showed the cases being printed! its an easy fix to either print extra hinges or better, incorporate hinges in the initial disign. or just use a sheet of thick, stronger fabric, isoloate the sunpanels on the back and use something like velcro to put them on the fabric. Makes it modulair and the fabric is the hinge like the one you bought.
Awesome project, as always. I'm wondering if you can build your own MPPT? It would be for sure interesting and many people would welcome this project :) Thanks for your work!
That 36 cell frame failed because the epoxy resin you used was for small resin art there is different resin for large projects because if you use small art resin for big project poured all at once it will Burst when it hardens.
I once thougt about the same. Then I did my calculations and got a number about 10w Paneel to charge a phone enough for a normal use ( everything lower limits the user). I compared different products and bought a 10w paneel, a direct usb controller thing and a power box. The paneel with controller costet togheter 15€, and the bower box because I think that when you want to get the macimum out of sun you have to use all of it, place the paneel with battery strategely and wait for it to collect. It works extreamly well and the small paneel fits easyly in travel luggage. It looks a bit bad but I really like it The DIY setup in the video is a bit overdoing it, but on the other hand it will charge with worse weather conditions! still very briddle design ^^
12V Solar system panels work well with car USB chargers! The nominal panel voltage is 18V, and the Voc is under the 24V that most car chargers work up to. You can mix and match panel and charger wattage - 5V only (5-12W) or USB power delivery (10-60W). The main problem is no MPPT functionality, so a temporary shadow will collapse the panel output voltage.
A lot of those only go up to 1.5a max and few really put that much on each port when all the ports are in use. The same applies to these overpriced yuppie panels that look nice but rarely deliver regardless of the latitude as some perform like crap even on a good day in Mexico and Spain. A Good one will put out around 2 amps per port and not sag when both ports are in use.
@@davidgunther8428 People have been using panels for charging 24v and 48v systems running lithium batteries for a decade or some for homes and businesses. I honestly don't like lead acid batteires as they are bread and eggs that they don't have the best shelf life in the long run. I got lithium packs that are 15+ years old that still hold decent charge.
While the DIY option is the clear winner for price to performance, I feel like the nicely backpack carryable nature and small form factor of the buy makes it a clear winner for practical use
Awesome project again! Consider replacing the small wires linking the panels with two hinges. There should be more electromechanical modules, like hinges.
Epoxy resin is normally too unflexible - differences in thermal expansion between the resin and your cells will most probably crack the cells. Polyurethane solidifies into a more forgiving coating.
DIY is the winner if you never leave the garden. I have exactly the same issues. I using my DIY for years. and finally got the exact same solar panels that is showing up here. I can get 1.5 amp from advertised 14W. the overall for me is to buy on. in this case DIY lose. Great video. thanks for the efforts. it was very helpful for me.
At about 3,5v or less the buck boost output voltage rises up to its maximum (30v or more) and it starts consuming an big amount of current from the source, have you experienced something like this ?
It's a great video, like all of yours however, it didn't quite cost around the same as the commercial option as you must include the cost of the time and the 3D printers etcThey look like pretty good 3D printers to me.
If you haven't figured why the multimeter was showing a very less short circuit current value when tested on a single solar cell, then its due to the inability of most multimeters to measure accurate current values in very low voltage like 0.5 volts. If you connect 20 of them in series and measure the short circuit current in bright sunlight then it will show a current reading very close to the manufacturer specification.
When I get the notification that GreatScott Uploads when I wake up, I feel so happy and pleased! I have followed your channel since 200 Subscribers, and I knew that you would become amazing like this. Keep Uploading!
The sunpower C60 solar cells are the ones to go for. Much stronger mechanically - still fragile, but stronger than the ones you used. All the connections are on the back, which makes wiring them up easier. They have a higher output - you get five amps in strong sunlight at maximum power. Open circuit voltage is a little higher - just over 0.6V. Size is 125mm x 125mm. You can find them on Ali Express. I've used them to build solar-powered radio control planes - no batteries on board at all. Even when the sun goes behind a cloud, or the plane is inverted, there is still enough power from ambient light to work the receiver and servos. An on-board Arduino monitors the voltage and controls the motor speed controller so that the voltage is never pulled too low to cause reception problems. Ten or twelve cells in series seems to be the sweet spot for adequate power with a reasonably-sized model.
Hi Scott! I'm enjoying and learning a lot with your channel about electronics! I'm in the process to buy a 3D printer and my choice is Prusa. I saw your MK3 review and saw on this video that you have the Mini + too, correct? ...how do you like the Prusa Mini and even I have the budget for a MK3, but I'm a beginner, should I go with the Prusa Mini? Any feedback would be greatly appreciated? Thanks
I think mostly these solar panels provide too less than what is being advertising. Better to use Hetrojunction 28% Efficiency High Grade Solar Panel which is only Made in Europe and mostly used in Space application. But yeah, that is the expensive part. The economic side, one should check the brand and manufacturer reputation before buying them. Scott is right, the wattage promised never achived, I have tried it too.
Yeah I’ve only seen one panel or cell ever hit even close to spec (and it went above spec pretty consistently). Almost all of them are way under what they are rated. Really sucks when you are trying to design for a specific load and it drives the size of your design based on an incorrect and made up marketing rating that is simply impossible so then you have to completely redesign because of fake specifications...
Today I finished the project. Same cells! 10 of them. If I hook it up to a powerbank with 10 18650 LiIon batteries of 2.2 Ah in them, I get around 18 Watt in full sun (So I connected the batteries directly). I also tested with a 6Volt lamp, but it only got 12 Watt at 5 Volts. Clearly the cells perform best at a lower voltage per cell (0.37 Volt per cell). I am thinking of charging LiFePO4 batteries with it, since those like to be filled at round 3.6 Volts, and float round 3.4 Volts. But I am also thinking of making my own MPPT circuit for it, I found one with just 2 NE 555 chips and a few other components!
*CAUTION LONG READ* The use of a boost/buck converter will be not very efficient by some reasons with a 10s solar cells panel aiming for stable 5V output. The main problem is that the boost/buck module you used (only voltage regulated) can't limit output current (neither input) what will make the solar panel voltage fall to the minimum (as like when you short it to get Isc) if you connect the converter output to anything that does not regulate input current to avoid the converter sinking higher than your solar panel 'Imp'. (mobiles phones or power banks use to limit somewhere between '1.2A' to '1.5A' so that's why coincidentally it works aceptable in your experiment). In other words, if you connect the converter output to anything that will make the converter input sinking '>=' the solar panel Imp (maximum power point current), (I calculate somewhere around '2.4A Imp' as your cells show '2.8A Isc') the solar panel voltage will fall (clive voltage curve area) so the power the panel can generates will be much lower than the maximum it could if the current is limited to its MPP area (maximum power point). What will happen if you connect a device that can make the converter sink more than you solar panel 'Imp'? (imagine you connect a device that sinks 3A at 5V) you solar panel Vmp is around 5V, great, but the Imp is around 2.4A, nothing stops the converter to try to sink 3A from you solar panel, so the converter will try to sink 3A and will makes you solar panel voltage to fall (according to its curve) upon 0V once it reaches 2.8A, wasting a high amount of power the solar panel can produce. Of course the converter won't ever output 5V 3A, but will still trying to output 5V, so if the device can't also limit current below 3A, it will make converter output voltage to fall below 5V trying to get 3A and similar to the converter, reset itself once the voltage is too low. And what is happening on the converter? If they have a minimum operative voltage, why are they still apparently working if the solar panel is outputing near 0V? Well indeed the own converter casually DON'T let the solar panel reach 0V, because while trying to sink 3A from your panel, once the voltage falls outside its operating voltage (maybe anything below 3v) it will RESET, stop sinking current for an instant, so the solar panel will recover Voc (~5.5V) for an instant making the converter again trying to sink 3A and then voltage fall again instantly to ~0V. This process repeat itself continuously an it is smoothed by converter input capacitors. The practical conclusion is that you see that somehow it works but the power you will get from your panel will be much lower than the maximum it can output if its current can be limited exactly or close its 'Imp'. *IMPORTANT: all these calculations take into account your solar panel is always at maximum solar conditions ('2.8A Isc' in your experiment), when the solar intensity will be lower, you will have the problem of the reseting phenomenon (panel going close 0V) at less converter output current and the efficiency you will get with the converter will be extremely low. The main issue here is the efficiency of your system. Not only because buck/boost converters units (~80% maximum efficiency) are double inefficient (two transistors / diodes instead of one) than single buck or boost converters (~90% maximum efficiency). It is because you need a converter that can "see" if the solar panel voltage is below its Vmp and stop sinking more current to get its maximum power available at that solar intensity, and that's called the famous MAXIMUM POWER POINT TRACKING (MPPT) converter. MPPT controllers are expensive and not really available for small power solar panels. Those you can find as 5V, 6V or 12V MPPT (2A - 5A) modules are not real MPPT, they just stop sinking more current for a fixed voltage (5V, 6V, 12V typically), so we could call them FMPP (fixed maximum power point) converters. Although they can't track the solar panel actual Vmp, this value does not change so much in direct sunlight, independently the sun inclination, and rounds 0.5V per cell. What I think it is a better alternative solution? Just using a BOOST converter unit. If the output voltage is configured at 5V it won't regulate for a higher input voltage, but the solar panel with a blocking diode can't output more than 5.3V in any case, what is completely inside the maximum voltage window on 5V USB specifications (5.5V max). It will have the same bad behaviour at output currents close or higher the solar panel Imp, but the converter has half the power loses than a boost/buck unit.
This is why all those fancy but otherwise junk foldables rarely work as advertised, there are some panels out there just for usb use that don't have anything between the panel and the device.
That's really cool :) But here are my couple of points. 1. Never test a charger by connecting a smartphone. Smartphone charging current depends on everything: source voltage, connection, wire quality, battery charge, temperature, smartphone os load. Just don't do it, it's unreliable. 2. Ideally, add a battery (make it a solar power bank), and use the MPPT. 3. Don't let the wires bend without support, it will break very quickly. Ideally, don't let them flex at all. 4. What happened to that blue frame? :)
Great video as always. I have already ordered some solar cells to do a similar project myself. I see you used tab wire all the way the cell (3:57) and only part of it (5:26) is there any difference or I can just solder it partly? Most people solder it all the ways but I don’t know if it is really necessary
Afew weird questions for you @greatScott. 1. What pens do you use? I have always wondered this . 2. Will the epoxy you used yellow in the sunlight? 3 If it does yellow, do you think it will effect your solar output much? Thank you and keep up the great work.
Love your videos Scott! But sometimes those testers can stop your phone from drawing quick charge amps (Amps greater than 1) usually. To test the actual output wattage having an appropriate load is a better way of doing it I feel. Though I wouldn't be surprised if the cell is a fraction of claimed as that does happen a lot. I am just speaking from personal experience. You tester might not have that issue. Thanks again.
0:57 Isn't that the phone says to the charger how much Amps it needs the charger to give?? connecting a different usb device, draws different Amps, that's not how much Amps the Charger can give but how much Amps the device asks at the moment. ??
I think DIY is more capable, because you can design in a way that you can add any number of panel strings (to match the power required for example a "fast" charge of car battery) and also add two outputs, one with fixed 5 V and another with adjustable output voltage for small car appliances, car battery charge, custom electronic board or liion battery custom pack designed to run offgrid.
What is the advantage of using solar cell flat wire instead of garden-variety round copper wire? It doesn’t look like the flat is easier to solder, and the flat also appears to be more fragile. I don’t have any flat wire to measure the cross-section, but it seems like the flat would have higher resistance - something that would become more important as the string gets longer. I have some solar cells and have been wanting to do a project like this for a while, so I’d really like to know which one to choose.
Mppt and a thermister to temperature compensate the mppt setpoint of the panel this will maximize the available power from the panel. I used a 100W panel for my 7.2A Lipo battery.
Maybe I'm wrong, but as far as I remember from my electronic knowledge about smartphones, you need to have a either snapdragon/exynox chipset which accepts higher currents for charging. Without that the phone caps the current to less than 2.0 A at most for safety reasons.
All recent major phones have a fast charge ability, but usually uses 9V or higher for >10W charge rates. Getting large currents through a USB cable/connectors is inefficient.
@@davidgunther8428 I didn't explain myself properly sorry, Yeah that's why I try to say when talk about a Chipset capable of handling these currents. For conventional, fast and super fast charge. The phone I see on the vid (Galaxy S4, old generations of a Jx or Ax) is fairly old and I can bet it can't handle something like 2.5A
@@diegoG21 my S10 charges at 15W max, but that's not at 5V input, it's 9V, so the current is about 1.7A. Maybe you are mainly talking about the power level older phones charge at, not specifically the current? Yes, a S4 isn't going to be able to accept charge at a high rate. Most newer phones do (past 2-3 years) but they need a higher voltage source and proper data signaling to let them know what they're working with.
@@davidgunther8428 My iPhone 11 Pro Max charges at a confirmed 24 watts when low. It tries very hard to pull the maximum 3A from 9V. It won't shift to 12v since it can't max out 9v. In other words, without USB-C PD, neither the "buy" or "DIY" option is relevant. This is ironic as USB-C is his latest love.
Oh, the joy of soldering individual solar cells and encapsulation... Is that resin good with solar exposure, as i recalled that was one important aspect to choose the product.
Now here's the thing . I really want to know why people consider connecting the cells in series in order to increase the voltage . When we have such good and efficient buck-boost converters which can increase the voltage with 95-96 percent efficeincy , why do we add them in series because in series not only the voltage increases but we have a huge demerit , that is the effective series resistance which adds up and ultimately screws up the max power output of the cells . So i would love to know why connecting series is a good idea to increase voltage rather than just connecting all cells in parallel and then just taking a boost converter to increase the voltage
Maybe add the hinge halves to the printed frames so the frames connect by their own hinges. A separate hinge pin can be glued in place at assembly time.
Ich finde die Buy Variante wesentlich besser, klar hat deine Konstruktion mehr Leistung, ist dafür aber wesentlich größer und wird die mechanische Belastung beim Transport in einem Rucksack kaum überleben. Außerdem wird die höhere Leistung nur bei einem starken Abfall der Spannung erreicht, wodurch die Leistung nicht zum aufladen genutzt werden kann. Dennoch ein interressante Video😃
Great project! Just a simple question, why did you use spacers on your 3d printed frames? Is it so that the resin can go below the solar panel as well? It seems as if having the spacers there would make it easier to break since it only rests on 4 points
The short circuit is barely 3 amps because the multimeter has a resistance (the shunt) that limits the current. You always have to put that in mind, especially when dealing with really low voltages or measuring short circuit current.
@@greatscottlab yeah, let's assume the resistance is 0.1 ohm and the output voltage of the solar cell is 0.5V, then the the current reading is limited to 0.5V / 0.1 ohm = 5A. Also don't forget that when doing a short circuit the voltage drops so it will make the case worse and the reading won't be accurate anymore.
