Cheap(est?) PWM Solar Charge Controller - 12v Solar Shed

I bought this solar charge controller on a whim - it was cheap. Could it really be microcontrolled and PWM for £3.20 / $5?
In this video I test out it's claims.
❗️These links are affiliated and I may earn a small commission if you purchase❗️
This item was purchased from Ebay: goo.gl/Q76ryo
See an update to this video: • Cheap(est?) PWM Solar ...
See the Lithium Ion Version in action: • Cheap(est?) Lithium Io...
Thanks for watching - It'd be great to hear your comments.
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[@eCitizen1]

I really like this detailed review. You approached this with the requisite skepticism needed for such a cheap component. I could not find another thorough look at this little device, and thanks to you I am willing to buy some of them. Thanks a lot.

[@Legend813a]

The dip switches are for time limiting the load on or off. 1111 = always on 1110 = 1 hour 1101 = 2 hours 1100 = 3 hours Etc 0000 - sundown to sunrise

[@edoardocastellaneta271]

Great video as always Adam! How a product can be designed, assembled and sold for just 3.20 is just a wonder of chinese economics.

[@AdamWelchUK]

+Edoardo Castellaneta The miracles of mass production and the magic of China Post!

[@jethrotull5847]

Started watching this video and realized it’s pretty old. I’d settle for a dumb, reliable PCM controller with LI battery mode as I make pole mounted solar cameras and other appliances. For now because I find nothing that completely satisfies my requirements I use a “Tasmotised” D1 Mini and a MPPT module. ( they are offered on Amazon prebuilt on a pub. )The D1 mini logs charge state and current via a ini-219 sensor. Data is collected via mqtt. over wi-fi. It seems no vender offers pre built solution. The closest solution I’ve found is a Renogy 10a PCM with a Bluetooth interface. Approx $55 USD and no ability to use mqtt. Arg ! BTW this part is for everyone else.. use a clean dc source to emulate a solar input with a pcm device. MPPT can handle dirty dc but PCM controllers freak out !

[@Timberwolf469]

I put one on 165w panel and a car battery for 5 days now and its working great

[@AdamWelchUK]

Excellent. They are decent little units as long as you take into account their charging profile. 14.4 (if memory serves) might be a little high for some people, but on a car battery (that may have needed some reviving?) it's not bad at all. I hope your not getting great sun though - 165 watts at around 18 volts maximum power would be 9 amps even at 14 volts that is probably 7ish? - perhaps you are using the newer 10 amp model?

[@Timberwolf469]

Thanks Adam you made me stop and think about it. I can't say it works great but I haven't killed it. I have a Sharp NE-165U5 P-max 165w -V o c 43.1v - I s c 5.31A solar panel Solar Controller DHS-3s-12v3A I got it because of this video (I like you work) max charge output stops at 14.9- 15v Still to high but fun to play with. I'm going to try the updated one 10A Thanks again

[@AdamWelchUK]

+Timberwolf469 Ok so it looks like that's a 24 volt 72 cell panel. Which isn't ideal for a 12 volt battery as you'll be holding it way down from its maximum power point. So in reality it's probably only producing an amp or two which is why nothing has gone bang. Might not be much advantage getting the 10 amp version - although they are cheap. Thanks for the kind comments.

[@xanataph]

Well, you can never have too many charge controllers! They are to the solar enthusiast what distortion pedals are to guitarists...! lol Yep, that 14.8V boost is definitely too high to regularly slam into an AGM, but those voltages would work wonders on flooded batteries which typically get charged a little low by most controllers.

[@JulianIlett]

Great video Adam. That controller looks brilliant for the money. I was also wondering about the switches. If you could get more of those misfits, you could put them in parallel (stacked vertically). I'll be buying a couple.

[@AdamWelchUK]

+Julian Ilett Thanks Julian. If you have a look around ebay you'll find that some versions are sold as lithium ion chargers (8.4volt), and even NiMHchargers (7.2volt). My initial guess was that the dip switches either indicated to the code to charge using a different profile, or simply added in resistance to the voltage divider. Unfortunately after trying the dips in as many combinations as I could think of, and finding that the PIC wouldn't boot with half a dozen NiMH batteries attached I gave up on that theory. It would be interesting to beef it up a little to see how it fared with a few more amps. I hope to see them in one of your videos in the future - perhaps you'll have more luck finding out what the switches do.

[@Legend813a]

Load timer

[@slybunda]

is it possible to reprogram one of these to lower the float voltage and even reduce the clock speed etc to lower its self consumption?

[@Excityboy63]

Hi Adam.....Great Video. Ordered 2 last week based on your review. Hoping to marry up one of them with my daisy-chained 10watt Powerfilm folding panels. They put out 15.4 Volts / 1.2 amps and I've never been comfortable directly connecting them to a battery. This controller looks like a solution......Thanks

[@AdamWelchUK]

Glad you found the video useful. Thanks for your comments.

[@MartinDoyle]

Thanks Adam for a great video and insight into this charge controller. I've just bought one on Ebay but almost bought one rated at 11.1V and noticed there were others for various types of battery. Anyway, we'll see how it fairs and it might be put into use in the shed with the 40 watt panel, leaving the trusty PWM5 for the 70 watt panel... Unbelievable how they can make a proper PWM charge controller for this money...

[@AdamWelchUK]

+Martin Doyle I'm glad you noticed before your purchase! As you've found there are a few different versions for different types of cells. I did hope the switches inside could change the battery type - but after trying various combinations I'm not too sure any more. I have ordered another which is sold for charging lithium ion batteries to look at the difference. Thanks for your kind comments - hows that floor coming along? :-)

[@MartinDoyle]

Floor is done! Unfortunately shed has been temporarily comandeerd by the wife to store hay which we reshuffle a few things. Once I have it back, I'm tweaking the solar bits...

[@JamstaUK]

Nice vid! I've got one of those. When simulating the solar panel with a DC-DC converter like you did, I found it got very hot at 2A when charging a battery. It's not great that it has no sinking at all compared to the other cheapo charge controllers on the market.

[@AdamWelchUK]

+JamstaUK Thanks for the kind comments. There isn't a lot of heat sinking no. I guess if the battery is full and the pulse width is small the mosfet could start to get warmer. I wonder if using Julians suggestion in the comments here might help - stacking mosfets?

[@scottwood9181]

Any clue what would cause the leds to strobe? I had one hooked up working fine and now it strobes all three leds alternately. I ordered a 5a/10a version and same result when I hook it up. It works fine on another controller.

[@Chickey]

Cracking vid, think i might have to purchase one or two :-) Although saying that i've just bought a load of components for making some charge controllers using your design with the ATTiny.

[@AdamWelchUK]

+Colin Hickey Thanks Colin. They seem quite good for small systems. It'd be good to hear your feedback once you build your own.

[@Chickey]

+Adam Welch Will do, i've still only got my small 10w panel and looking to find some reasonably priced larger panels. Got my eye on a few 100w panels after your advice on the other panels i was looking at.

[@patrickcourtot6417]

Hi Adam, Thank you for all tour Work. I just finished two lithium battery packs. As you, I connected them to different solar controllers. My question Why do we need à controller? . I connected a 12V 100W solar panel directly to a BMS and a got 1 amp more than with the controller. So more than 10W what is significant.

[@AdamWelchUK]

+Patrick Courtot In many respects you have two devices doing similar tasks. They control the top and bottom of the charge and cut off if those limits are exceeded. However a BMS is not a smart device when it comes to charging. It will allow as much current as it can handle. Charge controllers have different charging modes - bulk is full current, absorb is keeping the voltage at a set level by slowly reducing the current and most lead acid charge controllers will have a float level charge too. Your bms should keep the cells in balance and be a last level of defence against an overcharge. The charge controller will use a little power, and may reduce the charge going into a pack, but this isn't necessarily a bad thing. Thanks for the comments.

[@SimonBrisbane]

Any idea what the minimum input voltage requirement is to commence charging? I’ve built a large LED flashlight which is powered by a 12V SLA battery. I would like to have the charging option of a regulated 12VDC mains plug-pack power supply (which are common and cheap in the order of 300-700mA). I need a compact regulator circuit to charge the SLA Battery so it needs to boost the 12VDC to supply enough voltage to charge the battery while providing the regulated and controlled conditions the SLA batteries require for correct charging. It seems this sort of all-in-one circuit is very difficult to source so I was thinking perhaps one of these PWM or MPPT low current solar chargers might be able to do the trick. Obviously they would need to be capable of running from 12VDC with some measure of efficiency.

[@taesan007]

Adam, can this controller handle 50 watt solar panel? Logically it should (since 50 watt panel's max operating amp is 2.8) but the manual tells to use 30 watt panel max....I'd like to know your opinion about mentioned above....

[@AdamWelchUK]

+Denis Lenskiy I think it can yes using the same logic as yourself. However check out my latest video - there's a new version that does 10 amps and I've tested that with 150 watts of solar.

[@taesan007]

+Adam Welch I have already seen it. Nice vid, thanks. But I have already bought 3 amp one. And I now hesitate if I can use it with my 50 watt panel.

[@AdamWelchUK]

+Denis Lenskiy I think you'll be absolutely fine with 50watts on the three amp version. The mosfets are rated much higher than 3 amp and the increased heat sinking on the 10amp version isn't that most substantial.

[@slybunda]

does this have blocking diode to prevent reverse charge? also when it gets dark whats the power consumption of the controller itself?

[@slybunda]

just rewatched and its self consumption is less than 6ma. is there any controllers that have any lower self consumption?

[@Lastaii]

That's a nice little controller. I wonder what those DIP switches do...

[@AdamWelchUK]

+Lasty Ah now there is a long and boring outtake where I try to work this out... so far I'm not having any luck with that! If I can find out, I'll post an update. Thanks for your comments

[@SimonBrisbane]

The DIP switch is for what they call “light control”. From my understanding you can set the output to always on or set a timer to predefined times. I assume the load must then be switched on when the charge LED goes out? (E.g. The sun has set, solar charging has finished) and/or a precondition is full battery charge??? DIP #1=8 H #2=4H #3=2H #4=1H (H=Hours). Just sum them for desired time e.g. #1 off #2 on #3 off #4 on = 4H + 1H = 5H. Default is Always On (All Switches set to off). All switches on = “Pure light control”. Perhaps this means the load will be switched off once charging recommences, not sure!

[@GabryelChannel]

I am using this as a Battery Protection System on my boombox, so I use a charger as Solar Panel, can I use ANY voltage charger? Which voltage you think that I should use? Cheers from Brazil!

[@qrsimon]

What happens if I hook it up to an amatek 30v? I am trying to build a wind powered battery charger for the (small) beachhouse. Nice video, I'll have a look at your other video's. Thanks

[@AdamWelchUK]

+Simeon pryns Hello. The mosfets are limited to 30 volts, so I'd be looking to leave some head room personally. Thanks for the comments.

[@quintenvanginderen8635]

I just bought one that looks exactly like this, i tested it and the output voltage was just as high as the input voltage. It was on no load though. Is this normal?

[@DC.images]

Would this charge controller and a 20w solar panel be good enough to keep a single leasure battery topped up with a caravan alarm fitted. Thanks in advance Dean

[@AdamWelchUK]

+Dean Clifford Hi Dean. This is pretty much what I do with my caravan. I've got a 20w panel which sits in the roof light. It's not perfect behind Perspex but it's better than the front windows which has a slight tint. Now I don't have a alarm, but I suspect it's designed to draw very little and a 20w panel - let's say even only running at 10w behind glass can product a few amp hours every day in summer. Winter might be a bit more of a struggle though with short days, low sun and lots of cloud!

[@DC.images]

Adam Welch Thanks for the reply Adam guess I should go for something with a little more umph nearer 50w

[@AdamWelchUK]

+Dean Clifford Could do. You'll find it's overkill in the summer though and obviously it'll be a bigger panel to fit where ever you choose to mount it. 50w is also about the maximum for these 3 amp charge controllers. They do a 10 amp version now though which is almost as cheap.

[@thiagotrade101]

Hi Adam, can I know the rate of current to charge the batteries?

[@Timberwolf469]

no fires yet

[@GREEVES246]

WHAT PANNEL DO I USE FOR 12V AND SWITCH SETTINGS ? ALSO BATTERY ANYONE ?

[@SimonBrisbane]

Which panel you choose will depend on lots of factors. I use a 10W solar panel to charge a 7A/H SLA battery. The key issue here is what voltage does the panel output? Some are listed as “12V solar panels” but they put a maximum of about 13V out in full, strong sunlight. These are what you want to avoid. You want to look for an “open circuit” voltage of above 17V. These regulators work more efficiently with a higher input voltage. As for DIP switches, I answered that below where someone else asked the same question.

[@qrsimon]

maybe a 2nd question because I can't find it anyware. What is the maximum voltage that the controller can take? I dit the math on 3a, witch leaves around 16v at 36watt. is this correct ore can it do 20v?

[@AdamWelchUK]

+simeon pryns Remember that when the controller connects the panel to the battery either for a long time or a short one the panel will be pulled down to the voltage level of the battery - or close to it. As I mentioned in the other comment, the mosfets are rated up to 30volts - but your panel is more efficient closer to its rated voltage so a panel designed for 12 volt systems is best.

[@qrsimon]

Thanks for your reply. Can I wire 15 of there solarcells to meet the required voltage etc? I got these 6x6 poly 0.5v 4 watt. Do you consider this a panel designed for 12v?:) Thanks

[@AdamWelchUK]

+siemon pryns I'm sorry, building solar panels is not something I have any experience in so I'm not sure I can help you with this.

[@qrsimon]

It's oke:) I'll look further, there is much to read about building these.

[@John-gm8ty]

if your battery goes to 10.8v? wtf? that's going to kill them in no time ouch. 11.2 is considered dead flat and will seriously shorten battery life. bah, why the hell can't they make the discharge cut off user set? I won't take mine under 12.2 I want the bastards to last as close to their 10 year rating as possible. (thought, the Australia summer temps will probably never let that happen anyway) no, 10.8 is insane.

[@AdamWelchUK]

+John Douglas Yeah it's very low sadly. Why can't they make it user adjustable - money. Can't expect much for less than 5USD! Handy little charge controller for little projects though that is never going to deep discharge your cells. Thanks for your comments.

[@John-gm8ty]

but even the more expensive ones don't, it's one of the reasons I spend so much on the epsolar 2215BN, so I could adjust things, and now they've released the smaller cheaper ones, I'm thinking of getting one of those too for my 90w small panel (my big one is 250w) I've been looking for something small and waterproof to connect to the 250w panel to charge the battery for the axetracka, but haven't found anything than can handle that kind of power :/

[@AdamWelchUK]

+John Douglas Some cheaper controllers (like the EPSolar LS1024 I've reviewed) allow you to adjust parameters. I think the cheaper end of the market is getting more advanced now. There's some interesting products coming through.