Cheap(est?) Lithium MPPT Solar Charge Controller CN3722 - 12v Solar Shed
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- เผยแพร่เมื่อ 5 ส.ค. 2016
- I've been trying to find the cheapest solar charge controllers the internet can provide for a little while. In previous videos I've been able to recommend some really cheap PWM solar charge controllers but the cheap MPPT versions have been fake. This time however I think I may have come across something which could be classed as Maximum Power Point Tracking.
❗️These links are affiliated and I may earn a small commission if you purchase❗️
CN3722 Lithium MPPT Charge Controller: ebay.us/mTXQBE
CN3722 Datasheet: admw.uk/j5
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Thanks mate great video. I've been undecided on which charge controller to go for as I have many 18650 projects and all of your video's on this subject are a great help. Cheers
This Channel offers great Value! Luving it!
Your clear and well illustrated explanation is very much appreciated; thank you!
Thank you for posting this - I've been wondering about the details of how these little charge controllers do MPPT...
That's a really useful video ! Thanks for all makers that you helped !
This circuit is is simple, but nuts. It's a very good circuit. I have actually ran this MPPT board with my 60 watt solar panel, Output maxed out at 36 watts, Charged my battery pack 3S 11.1V Lithium Ion 10AH Battery pack and it recharged the battery faster than my switch mode power supply board i bought from ebay. That current conversion and 10% higher efficiency make all the difference.
My hero! Am looking into making a 18650 power wall for my campervan and this comes in handy.
Thanks to your insightful video I was able to build my waterfall. Using the second mppt you featured. I used:
18v 50watt panel
4s10p lithium ion pack
It charges amazingly.
I'm using a stepdown to 12.6 volts for 12.6 v 3amp water pump, fans, remote relays and on/off timer also some digital meters and lights.
This is the answer I was looking for. Thanks
I am using four of them with their outputs wired up in series across four Lifepo4 Batteries which are also in series! Each controller looks after it's own battery and when one battery is fully charged the rest keep charging! The batteries are always in balance! I love these little things 💟.. they really are that good!
@@PeterMilanovski , not to mention their price. Shout out to Mr. Welch. Thanks to him we were able to fill our needs
Thank you for posting this, I noticed that with the second module that the MPPT potentiometer did a better 10w (at 18v) on your video than the recommended 17.5v at 9.5w as you were adjusting it up&down
The available manuals of the second module recommend that you find the best MPPT point (constant voltage) of the panel you are using by adjusting the MPPT potentiometer
I also agree, I saw the second one peak at 10W when it was at 18.2V for the solar panel... I have since purchased a few of these and I'm impressed with how good they work! They can also be used in parallel for more current and I also found out that they don't like to have a solar input with no battery connected, they die, don't ask me how I know LoL. It turns on as soon as the panels see a tiny bit of light in the morning and won't turn off until it's almost to dark to see! They really try to get as much energy as possible!
After playing around with a couple of them, I purchased more of them!
I'm using 12v Lifepo4 Batteries and I have one of those controller's on each battery which the batteries are wired up in series! Apart from the 12V batteries having their own built-in BMS to balance the cell's inside, I don't need any other BMS because the charge controller looks after it's own battery and if one is at full charge, the rest keep charging! It's brilliant!
If I want to achieve 6A, can I use two of them on the same panel?
Thank you for this video, i wasnt sure if that little board was alright for my application.
Very helpful and informative review. Thank you for your time.
Hi Adam. Thanks for making this video. With your very clear language and explanation. I know now that this certainly is NOT a real mppt controller. But it seems to do a lot better then a simple pwm chargecontroller with only a regulation of voltage and current to the battery. Thank you once again.
Yeah, it's the cheap and dirty way of doing MPPT. You do lose a couple percent efficiency vs. a true MPPT, but at least it's better than PWM.
@@chrisw1462 It's an MPP controller without the T.
@@ahaveland Sorry, but if you search Google for MPPT, you get Maximum Power Point Tracking. If you search MPP you get a whole bunch of stuff that _isn't_ MPPT.
@@chrisw1462 You're taking this too seriously.
If it statically keeps the input voltage to the maximum power point and doesn't track, then it is not a tracker. It is an MPP device and not an MPPT device.
I don't care what others might call it or what Google says.
@@ahaveland If it's not tracking, it's not Maximum anything.. :-)
Such a great find 😊 thank you
very nice video sir. super, neat and clear explanation. keep spreading knowledge.
very nice explainations and clear voice! thx
Just arrived the MPPT controller for 12 lead acid battery. It has a few more components on the solar input side and clearly performs MPPT holding the solar panel at 17.34 V but varies to maintain current. I have replaced the small Cheap(ist) PWM controller with this one for my solar green house that uses a 25W panel and it has increase the output to the battery maintaining a trickle charge just above 13v.
I learned a lot. thanks for posting
You need to check the Vmpp at NOCT for the solar panel, not 25C. Panels are normally pretty constant voltage, so the datasheet is pretty much correct in that sense.
In normal full sun a 72 cell panel has a Vmpp of 36 Volts at 25C, but that's about 33 Volts at 65C (the actuall cell temperature). Your panel should list it's temperature coefficient on the rear sticker.
Useful info - thanks very much.
@@AdamWelchUK Yes, but you have a 12V panel at 10W. So not surprised they designed it to operate at 17V - 18V Vmp.
Hi Adam,
First of all I would like to say I love your videos !
But I would also like to place some remarks:
1. You should realy get your watt meters externally powered, so their own power consumption isn't influencing the measurements. (use the portapows or hack-in an external supply)
2. The mppt function of the CN3722 is really more a power point 'targeting' and it does a really good job, especially if you actually use the temparature sensor and mount it on your solar panel.
This since the mpp voltage is fairly constant, but temperature dependent (that's why they note Vpm on the panel 'at 25deg')
3. Note that the power USED by the charger depends primarily on the battery state. And if the solar panel can deliver MORE power than required for charging it will never be in it's maximum power point (resulting in a higher panel voltage)
On the other hand, if lighting conditions are insufficient (clouds) the solar panel will NOT reach it's nominal maximum power voltage (resulting in a lower panel voltage). So the mppt will only be effective in a small range of conditions.
4. When just charging batteries
the battery voltage is 'fixed' so you get an optimal harvesting of energie when you maximize the charging current.
5. The mppt circuitry will lower the current drawn when the panel is below it's Vpm, so on low light conditions (when the panel never reaches Vpm) the output current will become zero !
So do we want mppt at all when just charging ?
As long as the panel voltage stays above the battery voltage (and the buck working voltage) a buck converter will still try to provide the maximum possible current into the battery....
Just give it some thoughts,
and keep up the good work !
yes, but its mandatory to use a temperature probe on the panel. MPP voltage gets quite lower when panel heats up and if you dont monitor the temp, then you might be getting no power at all when still on MPP voltage of 25 deg.
What do i use to charge my enjoybot 100ah battery? I think i want to use a flexible panel on the car rooftop if it will fit. Sw Michigan i think it's like 13.1v lifepo4
the MPP changes according to the irradiance available at any time so the voltage and current also change. The nominal MPP is based on 1000w/m2 insolation so unless you have exactly that, the Vmpp and Impp will be different than the nominal mentioned in your panel.
I was giddy with excitement watching this because I've been looking for a decent cheap charge controller for an 18650 lighting project I want to make. My wife groaned when she saw what I was watching.
I will grab one and a 4S BMS, a solar panel, an adjustable buck, and some chip LEDs. Home free!
+pepefpv Glad to be of service!
+Adam Welch Looking at panels now and I'm a little confused. Because I want to run 18650s in 4S, fully charged the pack will be 16.8v. I was thinking an 18v panel would be better, but all the ones I can see appear to have a built in regulator for 12v pb batteries. So will a 12v panel work OK in this situation, or can anyone recommend a suitable 18v panel that isn't $100?
+pepefpv 12 volt panels have their maximum power point at about 17-18 volts. They might work ok for you. A 24 volt panel would supply voltages too high for this little charge controller. 18 volts would be the natural choice, but as long as you've got a volt or so of head room you should be ok.
+Adam Welch Awesome, thanks!
Great comparison
Walk in front of the panel, and then check it. If it's anything like the (two different) buck converters I bought, they trip up. Hours later, the battery (3.2v LiFePO4) was only slightly charged, with a 6v panel. That should have been almost twice the amps into the battery than coming from the panel - minus inefficiency (what, 15% or so).
I'll try these but if they trip up from a sudden shadow, then _your arse is mine..._ LOL. This time, though, I'll try the slightly higher voltage of a real li-ion (a few in parallel), with your presented boards. If it doesn't work, then I know to put them in series (but that requires separate PCB for battery balancing - wraa...). It's just for my LEDs light.
Bty, thanks for the professional approach!
Hello Adam, you should try with lap power supply and CV and CC settings for solar cell and an electronics load for the load to get really good testings.
I Honestly Believe that as long as there is a External Voltage Reference Regulator for the Switch Mode Power Supply's Feedback pin so that it monitor's the solar panels voltage, you basically have a Somewhat Crude but very Effective MPPT Charge Controller because the Job of the External reference Voltage Circuit is to monitor the Panel's voltage so that it doesnt dive and you dont get maximum efficiency. Having a circuit with a Potientiometer that allows you to adjust that external reference voltage Is What allows you to tune your circuit so that you achieve the correct Powerpoint for that particular panel and your particular application.
Super in depth, thank you. I’m trying to create a, let’s call it solar controller power supply, so that when I’m charging my “solar generator” that connects to the PV side of the solar charge I can monitor the stats of my panels. The three controllers I’m working with will not turn on without being able to “see” the battery on the batt. Terminals. My hope is to use one of these controllers and a simple 3s 18650 pack and connect this little power supply when I’m charging my solar generator, would it just be a matter of feeding that voltage back to the controller, probably with diodes to power up the solar controller?
Suggestion: When testing the output voltage, you can remove the batteries, and use a large capacitor on the battery side of the MPPT to adjust the output voltage of the MPPT/Charger.
It's possible but not while the solar input is active, no load on the output will kill it. Don't ask how I know lol... This is it's only fault, otherwise it works extremely well...
CN3722 MPPT is very nice module !!!
That is what happens when you get salesmen writing data sheets. This is a MPPC chip and that temp sensing input is for a temp sensor on the panel, NOT the battery. Frankly I am a big believer in MPPC and all my controllers at camp are MPPC. Power point voltage really only needs to be set seasonably as typical panel temps don't vary much. The big advantage is multiple controllers can be set to slightly different voltages as little as 0.1V difference to give priority to loads. This allows me to charge battery as primary and secondary send any portion of power to a water heater. This all happens seamlessly. While this chip has LI charge control, any buck converter can be turned into a MPPC controller or Linear Current Booster for pumping water without a battery.
I agree 👍 I am using the second one in this video and after watching it and setting up the mppc plus the cutoff voltage, it just works! No hunting around for the best point when a cloud will pass overhead! Some days I think that the MPPT charge controller that I used to use spent more time hunting around than charging! Because they won't charge until it's found the point! These things work in parallel or series or both LoL.. super flexible... I love it 💖.
very nice info
+jehugarcia Thanks Jehu.
Garcia papa tu me apareses hasta en las sopas lol
Very nice review I've wondered about these solar chargers for 18 650 batteries . I have a need for a small project that involves a PIR sensor and a esp 8266 processor. I think something like this in a 10 watt solar panel. Would keep it charged up
I have just bought and tested the 3s mppt controller , used a variable wall charger at 16.5v to replicate solar input ,the controller did charge the battery pack but wow it got super warm I think it would need a huge heat sink lol
The bigger 5A version is very interesting. I wish they would offer also a 10A version with a better build and assembly - that would be justs what i am looking for :-)
First off, yes, with temperature on panel constant the peak power point will be at a certain solar cell voltage. It will not change based on solar influx.
Once you have set it up for your panel it is good to go. The slight adjustment needed by temp to keep it on track looses minimal power compared to not tracking at all.
As you pointed out it is very specific to input and output voltages so one can resolder to adjust if possible, or adjustable may be preferred.
The higher power designs are as you also point out not as efficient for lower powers. This goes for the expensive controllers as well.
Only way to really confirm it's close to the max power point would be to have repeatable solar influx and test it by load testing the panels and creating the curves for them and compare against what you get from the mppt board. One way may be to simply set a fixed resistor on the output to give a similar load instead of charging an actual cell which will be varying a lot.
You will be surprised at how close it is to peak. Hope you are still having fun with solar!
What do i use to charge my enjoybot 100ah battery? I think i want to use a flexible panel on the car rooftop if it will fit. Sw Michigan
I think it's like 13.1V
its more like a manual power point tracking (mppt) device, but as long as you can track maximum power transfer point at the battery side, you should be ok, i guess.
Manual is so much better! I have had the opportunity to use an automatic MPPT charge controller and half the time it spends looking for the best point while the battery is not charging, it Hunt's around every single time a cloud will pass overhead... Not this thing! I'm really impressed with it's performance! I don't think that the solar panel ratings printed on the back are exactly accurate! I have tried different wattage panels and these charge controller's can be adjusted to get more than 20W from a 20W panel.. I have tried other wattage panels and it's exactly the same situation there too! I have since purchased over 10 of them... They just work so much better than anything else that I have tried or seen...
@@PeterMilanovski ah, you reminded me some very old stuff. 😁
Thank you for posting this nice comparison! I would like to use a BMS with one of these. Have you run tests with a BMS? The BMS has its own (pre-set) voltages that can not be adjusted, so how much does a BMS mess up your good values from a charger like this. And what is the efficiency of a BMS? How much do I lose there?
Looks like a decent little board for the price. Have you managed to find anything similar but facilitating a single lithium cell or a simple 5v / USB out?
Noticed towards the end of your clip that the wattage into the batteries increased when you moved the pot away from the panel MPPT voltage.
Wouldn't it make more sense to peak the wattage input to batteries, as opposed to the wattage fed into the module from the panel.Great info though, keep it up.
The CN3722 does a very simple DC-DC power conversion. In a way, the it is not a true MPPT solar charger because it does not scan the input power to find the actual maximum power point. Rather, it is a fixed input voltage converter. What it means here is, there is a pair of resistors that sets the voltage level where the solar panel provides maximum power. For most solar panels, this voltage is around 16~18V. If you have a battery that is at 12V, the difference between the MPPT voltage and the battery voltage is loss in efficiency. By regulating the input voltage at 16~18V, there is efficiency gain. For a smart MPPT solar charger with build in micro controller, the MPPT charge controller scans the input voltage/current to find the actual MPPT. But for this particular "dumb" MPPT charge controller, the input voltage is fixed. Thus, yes it does work, but it is not the actual maximum power point, especially if the panel is partially shaded. One advantage of this MPPT charger is there is a back flow prevention diode build in. Thus, at night, the battery won't be powering the solar panels.
Adam, at 14:43 of your video you mentioned something about a balance board possibly balancing each series as to avoid unbalanced cells. Which board would you recommend for a 4s7p battery pack. Thanks
thanks for the video, this is not doing mppt it just regulate the panel voltage which is not mppt. Question : did you figure out why the efficiency is too low?
Thats a pretty neat board , i can pot it in a box and use it to trickle charge my car cus i rarely drive my car and it ends up with a dead battery after few years.
Thanks for the video, Adam. I have ordered the first unit from eBay to solar charge my 3S 18650. How would you tap the leads from the controller to the load? Directly from the +/- battery leads? I am using it to drive a 12V motor.
nice video! what make power inverter in the 400 watt range would you recommend?
Having tested this at 17,6v Solar input only you are missing the point of this board. It switches the output to be most efficient at lower changing voltages when e.a. the sun is dim or clouds are in front of it. So it's the dynamics of changes that give it its MPPT characteristics. You could have used a power supply with variable output voltage to simulate this.
Thanks for the video. I saw this same board and they ask if you want it for LiFe LiOn or Lead acid but I have to assume they all use the same IC and since I need to charge LiFe I might need to look elsewhere...
So despite the incorrect solar panel voltage, the first one is actually more efficient. It gets more solar watts into your battery. Replacing the resistor divider on the first one with a pot would seem the best option then.
One problem with the circuit that I see is that it can't measure the power going in. The way that MPPT works is by measuring the power coming in, and then adjust the input voltage so that maximum power going into the circuit is at maximum. Then use DC to DC converter to put the voltage at the desired charging voltage for the batteries.
A nice video but I feel these two watt meters are effecting results. Because you are only using such low watts with them in this test they each are drawing a significant portion of the power away from the charging of the load. I feel you need a much larger load. These test should not be done on a battery that is almost fully charged because the watt meters will be consuming a significant portion of the total load of the panel output as compared to what the battery is consuming.
great videos! Is there a way of solar charging a 48v ebike battery while you drive the bike?
Awesome little handy modules. Would love to see how accurate they charge and what actually happens to the charging process when the sun goes away for a while (not that that ever happens LOL)
Now I'm electronic man myself but I am starting to struggle with a bunch of naked pcb's that end up in boxes. You make the same 'mistakes' as I do and that is to solder the wires to the board without any mechanical protection.
Wouldn't it be time if everyone starts using standard size pcb's and we can get cheap modular cases? Luckily some sellers are now offering these lego style see through cases but when you have to order them separately the price of the module doubles.
Anyway great video again and yes I had a question mark stuck in my head about the mppt treshold level and how they would do it with that seemingly not complicated module. And then you pulled out the other module.
heat shrink tube
great find, perfect analysis.Can you connect the output of the little red mppt board into to solar input port of a pwm charge controller (designed for 3s lithium) to get your super cheap mppt charge and load controller for a 12v rated panel with 3s lithium? what I love about the mppt chip is that it is powered by solar, so you could probably run a small pump off it without a battery and still get mppt.
+mjp0815 That's a really interesting idea using it on the input of a PWM solar charge controller which might just work. I'll have a think about that and perhaps give it a go. Thanks.
Adam, thanks so much for your response! Maybe on second thought just connect the output of the mppt module in parallel with the battery and the battery terminal of your pwm charge controller, I guess all that is needed is load management, I remember you did not like the way the cheap PWM controller was doing lithium charging anyway.
I Wouldn't be worried about the "tracking" as long as I can set a roughly correct Powerpoint. What worries me more is the loss of efficiency of the adjustable board compared to the fixed version. It seems this is much more significant then the missing mpp tracking.
The Increased Current limit to 5 Amps on the larger board is worth it though, in my testing with both boards, the smaller board with about 5 watts going through it had an efficiency of about 98%, the large board with that wattage was about 98 as well, but with 5 Amps being shoved through it, the efficiency was about 89-92% depending on the temperature outside, etc. But still, 5 Amps at 20 Volts Makes for about 7.5 Amps at 12.6 Volts which is an insane difference in charging speed!
Hi Adam, I purchased the second mppt controller in this video. I am wondering if I need to use a blocking diode on the battery side of this board. I basically would do solar panel - blocking diode (I'm not sure if my panel has one built in so I'm going to assume it doesn't) - watt meter - mppt board - watt meter - battery. do you think I need another blocking diode after mppt board or watt meter. any thoughts from you would he greatly appreciated. thanks
I have been doing the same comparisons with a 2 Amp, 3 Amp and 5 Amp MPPT board. I am getting similar results.
What I found is that the cheapest board (the first one shown) is set for a 17 vdc Solar input, and the output is set to 12 vdc. What they say for specifications is wrong. Also, the maximum current is 1.5 Amps instead of 2 Amps. Again, misleading. You have to change the CV ratio and the MPPT ratio on the boards to get them correct. Then there is the cheap parts they use. I blew the 0.1 Ohm Current Sense Resistors after a few tries. Probably rated for 1 Watt. I replaced them with 7 Watt Resistors and they are working fine.
The 3 Amp boards I bought had one adjustment for output voltage. No adjust for input. Still set for 17 vdc. They ran pretty well until, again, blew the 0.07 Ohm Current Sense Resistors. The current limit was 2.5 Amps. Changing them now to 7 Watts.
I have yet to receive the 5 Amp versions that are the same design as you have. I will test those next.
Thanks for this - very useful to know. Shame that it seems they've under-rated some components. Best of luck with the 5 amp version
Hi Could you do a video on converting a cheap PWM solar controller to
MPPT? Maybe add some inductors and ??? I don't know if it can be done.
Or how. Thanks Marty
I think you are confused about the MPPT voltage. It will always be the roughly the same no matter what the level of incident light. As the light level changes the output current will change (for a given load) and the voltage will remain fairly constant.
Hi Adam,
I'd love to hear about the efficiency gained from using this MTTP compared to the small 3A PWM you like so much.
I'll see what I can do, but I've got a few things on my list to compete first.
Thanks! Perhaps I'll beat you to it :-D
I thought this was quite an interesting approach. So ever since I watched your video I have been on occasion monitoring the solar input voltage going into my Voltronic MPPT charge controller. Interestingly, the voltage variance is not that great. It usually does stay around the MPP point of the panel, 17 volts. Occasionally it's 16 volts. It only goes lower under adverse conditions. i.e. *really* overcast sky, when there is shadow on part of the panel & at the end of the day when the light is low. This panel usually puts around 5-6 amps in decent Sun when the batteries require it, so the wattage difference between 16 & 17 volts is only about 5 watts. That's not terribly significant either way for a large panel.
The point being is that I believe under good conditions purely keeping the voltage at MPP is likely to be well good enough. It's only when those adverse conditions come that keeping a panel putting out 17 volts (or whatever the MPP is supposed to be) is likely harvest less energy than letting it fall towards the battery voltage.
+xanataph That's really interesting Xan. Thank you. I've not had a chance in the last couple of weeks to run a test like that. I think it's a reasonable theory that the designers have used and your tests seem to confirm. I guess monitoring the current on one side of the Buck converter and knowing the efficiency of the conversion you could assume the MPP on the other side too. Been thinking a lot about that little board!
Thanks again for your experiments.
Hey Adam! I bought a newer version of this chip but its a little different as it has a potentiometer on it. The ebay listing barely has anything to help the functions, it can do 1s to 6s i believe. Please check it out!
These things are still on eBay, there's higher power versions also, might be about that time to look into this again to see if anything worthwhile has changed?
interesting, i have an 18v /25w solar panel, so the smaller mppt board would put out the required 12.6v to charge the 3s battery pack?, or would i still need a 3s bms board too? thanks . i just want to be sure as i have had a fire with a 3s before lol....
LOL! A "book" converter! You plog in a book and the movie comes out!
thanks!
When you lowered the input voltage to 15 V, battery watt meter reported higher wattage going to battery, which is I guess better compared to 17.5 v on input
I saw the input wattage climb to the full 10W when he gets the panel voltage to 18.2V...
Thanks.
I believe the first controller is using that large low-value resistor that measures battery current to adjust panel voltage to the maximum battery wattage, because that's what we're after isn't it? The most battery wattage? If so, then I would guess that there's no reason to measure and monitor current coming from the panel which probably keeps self-consumption to a minimum.
Hi. I understand that following question might sound silly but it's comming from a newbie so please bear with me. I'm interested into making a portable battery system for charging my phone and tablet on the go (so value-wise 5V output with max of around 1,5A ) , using 18650's and auto step up/down converter (mine rated to max of 2A for in&out). Would it be better to set it up with 2+2 18650 in parallel (and get double capacity) or 4 in series (not sure here how this translates to total capacity since I'm stepping down from 16,8V to 5V )? Last question, is it ok to charge like you show in this video, multiple Li-Ions in series, using only end total voltage for charge termination and without balance port ? Thanks in advance and love the videos. Subbed !
The issue around charging batteries in series is that they start to fall out of balance as you say. One cell might be low, another much higher and the charger will keep charging - potentially an issue. Adding balancing circuitry adds to the complication of your circuit.
As a result most (all?) power banks on the market use batteries in parallel. That way they keep themselves in balance all the time. It also means you can easily charge from 5 volt USB. It does mean you have to step up the voltage when the cells become the power source, and there will be some losses, but it's not too bad.
It might be best to consider your capacity in Watt Hours rather than Amp hours. Lets take three cells - Nominal 3.7 volts each - 11. in total. Lets say they are 2000mAh cells.
In series they total 11.1 volts, and have a capacity of 2Ah that's 22.2 watt hours.
In parrallel they total 3.7 volts and have a capacity of 6Ahs and that is 22.2 watt hours.
So as you can see the results are the same.
Unfortunately if you are looking to solar charge your lithium cells I've not found a solar charge controller that works on a single cell voltage.
Hope that helps.
great job ! ;-)
AliExpress sellers sell (the first device as) 2s 3s variants. As i have one in hand ,asking if automatically detects output load, hence the voltage. Question stems as i want to charge a 2s and the device might be for 3s.
I recognized that turning the pot away from the MPP hightens the output watts to the battery while lowering the input watts from the solar panel. Assuming the important thing is what goes into the battery it seem to me that the whole mppt hype is a bit of a faustian deal, because whats the point to improve the output of the panel while decreasing the output to the battery?
As to u have shown this it’s nice but would like to know if any 6V3W circuit is there for
Sorry I got exited going to max volts made the second 1 more Efficient my bad you're awsome!!!!
I'm adjusting the one with the two pots. I only have one inline meter. Is it ok to place that between battery and charge controller and adjust to maximum charge rate? or should I do it differently?
When you adjusted the pot to change the MPPT point and you adjusted the volage down to around 15V you said that the input power had gone down. But you did not seem to notice that the charge power had gone up which is what you really want, i.e. more power into the batteries.
+FireballXL55 I've looked back and you are right. It seems the efficiency of the conversion isn't great. As the panel voltage was brought closer to the battery voltage (despite this resulting in lower power on the panel) the battery charge did increase. Perhaps one day I'll retest this. Cheers.
Yes please....a more in depth test would be nice
Adam Welch when the temperature in the solarpanel rises, the mpp drops.
If the temperature of the panel is 50-60°C it's very possible that the mpp is 1.5-2 V lower.
@@AdamWelchUK I would definitely watch that video, I have more than 10 of them and I just love how well they work... I'm powering mine with a 24V nominal panel and I have four 12V Lifepo4 Batteries in series with a controller connected to each battery! They are automatically balanced! And they can be paralleled for more current!
I love them... I have been looking all day through your videos and Julian ilet's also because I couldn't find this particular video, the second charge controller isn't in the thumbnail so I kept going past it LoL... I have been trying to send people to this video but now that I have found it.. hopefully you can get some new subscribers... But please, if you have the time and opportunity, make another video about the second one and put it through its paces... That is if you still have it...
Hi Adam .. just a quick question.. does that output to the battery stay at 12.6v for a 3S pack? I have a small pack that I am only balancing but not using a BMS. Just wondering if this thing would blow up my pack as the balancer probably couldn't keep up with the input.
At 28V max in, you can't use the large cheeper panels around 30-40Vmp.
You would need a boost controller to 13.4v for lead & gel 12v batteries.
Hello Adam, I have the same kit, what you showed in your video, please tell me the working of two given potentio meter. i could get .. please help me and i have one question more, when i trying to check the voltage drop across the terminals "bat+ and bat-" then it showing 0V, what does it means? (battery was not connected on that time)....... thanks
ty for this video :)
About the non-adjustable lithium version, is the final charging voltage (i.e. 8.4, 12.6 ...) automatically detected by the module?
The final charging voltage is set by a voltage divider on pin 10 - the feedback pin. It actually goes into constant voltage mode when this feedback pin hits 2.416 volts. So the voltage divider is calculate to suit what ever pack size you are after.
Can you tell me what i have to do to let the 1st board charge a 4s-Lion battery (16,8V) ? Have i to change R7 and what value?
Thanks for the video. Does the controller really stop charging at 12.6V or does it trickle charge?
It stops.
For the CN3722 "MPPT" means Manual Power Point Trimmable, halfway usable...
A complete fail was the CN3767 (should be for 12v Lead-Acid)
It never charges more than 13,55V, that is even not enough for floating...
Not to mention the necessary absorption level to avoid sulfation.
Actually the manual versions are better! You only need to set it once to your panel and forget it, same goes for the charge stop voltage! I have been using the second model in this video for some time now, I have a 48V series string battery bank made up of 12V Lifepo4 Batteries, I'm using one of those charge controllers per battery, each controller looks after it's own battery, no other BMS is needed! When one battery is at full charge, the controller stops charging but the rest continue so the batteries are never out of balance!
I was using a more expensive MPPT charge controller which automatically tried to match my panels but I found that every time a cloud went over, it would waste time trying to figure out the best point to set the MPPT, most of the time, by the time it figured it out, another cloud came over and it's back to square one! But this thing! Once set! It's fast from the slightest bit of light in the morning to the last bit of light late in the afternoon, it tries to get the last bit of energy!
This is just my opinion of it but I love it! It just works! I used to watch it all all hours and conditions of the day but I have since just given up... Totally hassle free!
@@PeterMilanovski Ok, you are pleased with not knowing what really happens.
Indeed with longer periods of low-light winter time they have an overall efficiency that is FAR below simple PWM controllers, since they will not begin to charge until the panel has reached 18V.
Then the CN3767 just charges to 13,6V and that is NOT adjustable. The battery NEVER gets a full load.
Thanks for the video, interesting little parts. May I inquire as to where you got those Watt Meters?
Thanks - Sure, eBay... goo.gl/QfvAeF :-)
Thanks!
So I noticed you don't have a 3s 18650 BMS connected to the mppt charger. Is that not required? I always thought it was necessary to monitor the individual voltage of each battery to properly keep the individual batteries balanced. Does this MPPT controller take care of all of that?
Thanks for the video, but is a buck converter enough to charge control a 12v battery from a 12v solar panel? I thought that you must have buck-boost, how can it just be buck?
Very interesting @ 12:40 min by decreasing the mpp Voltage of the panel the output power is rising.
Presumably, the only important thing about MPPT is that the power going into the battery is the maximum it can be, so using a perturb and observe MPPT method it should be possible to only measure the battery side current and voltage, multiply the two to find the power output and then adjust the PWM duty to the DC/DC and observe if if the power goes up or down and make the relevant PWM adjustments. I do not see an advantage, other than data gathering, for measuring on the panel side rather than the battery side.
mentioned in the video that the panel has a mppt point of around 17v, is this a value you calculated or something that was provided with the panel??
Provided on the panel.
How come the battery output drops when you adjust the mppt of your solarpanel. It´s still over the battery. Seen in 12:40
I would have liked to see the panel plugged directly into the battery, through the meter, to see how much power would go into battery... The charge controller seemed to deliver lots less power to the battery, than the charger could put out. Thanks.
reasonbly efficient ... to be honest ... i think 30% loss is kind of a biggie ... but its a nice video nicly showen and anjd also well researched with the data sheet an all but i would have liked to see a comparison with and without the mppt just to see how much difference it acctually makes but still thanks for the vid
You shouldn't focus on voltage. The charge pattern is fluid voltage and high amperage.
If you look the amp in is lower than amp out.
Usually the voltage floats until the battery is 80-90% charged then it becomes fixed voltage (battery voltage) and the current (amps) lower.
There is three stages...
1Current ( int charge) Max current (high amp)
2 fixed voltage (main charge)
3 float, (battery voltage) low current.
((Min current))
Off.
can we use 11.1 V, 13AH lithium ion battery which has 8 cell in the pack?
Solar cells need a voltage converter that keeps input current at max.. input voltage get lower as sun light max. diminishes. According to panel/power graph indicates. Use perturb and observe logic folks.
Where does the load connect up? Can it be connected directly to the solar panel and will the charger feed the battery energy back to the load when the sun disappears or does the load have to be connected directly to the battery. The trouble with the latter is that if the charger considers the battery to be fully charged, it will cut off the solar panel and use the stored battery energy even when the solar power is available.
I am pretty new to this module. Can you tell me if it is possible to charge less than 12 volt batteries, for instance 5v batteries using this module? Or it has to be exactly 12 volts output?
unless I misunderstood you, you actually got more wattage into your battery from the first and cheaper version. Or did I miss something?
No not really, as he started to adjust the solar on the second one, if you pause the video right where it gets to 18.2 for the panel, you will see that it actually got the full rated 10W from his 10W panel... He said that his panel should be set at 17.5V for maximum power point tracking but I think that it's actually at 18.2V. I have these and they are excellent! Their outputs can be wired up in series or parallel for more voltage or current respectively... Or both parallel and series at the same time for higher voltage and current... The are very flexible...
@@PeterMilanovski wait you can wire these up parallel? Also I think he set the output voltage too low, the IC seems to be on CV mode instead of CC mode
@@kaikart123 yes you can wire them up in parallel if they are connected to the same battery or battery bank!
I had purchased around 10 of these things and had been testing them on a 36V solar panel which can peak up to 45V, they are not intended to be used with 36V solar panels, the datasheet recommend staying at 24V panels or below, I have found that it can work with 36V but will fail if the battery is disconnected from it while the solar panel is delivering! I have burnt out two of them so far and both times happened when I was touching the test circuit, otherwise the first one ran for 4 months straight, as a load, I used a computer fan which draws 0.5A and an led light which draws 1A and this ran day and night. The second one ran for less time but that was all down to me fiddling with the circuit sooner rather than later... I don't think that it would burn out if I had stayed within the recommended 24V or below... This burn out problem might seem irrelevant but I'm using Lifepo4 Batteries which have a built-in BMS and they will disconnect from the circuit if there voltage drops below it's threshold value and this would cause the MPPT charge controller to burn out should the battery decide to go into protection! The battery would also disconnect if to much current is drawn so that's another potential problem....
But they can definitely be paralleled... Overall, I'm really happy with their performance! And I think that it has something to do with the fact that I'm using the 36V solar panels, I found that it would fire up with the slightest bit of light in the morning and still trying to get every last drop of light at the end of the day, it's actually pretty dark by the time it actually shuts down, first thing in the morning and last thing at night isn't really outputting anything but you can see that it's still trying to give everything that it gets LoL...
It does operate in CV mode, it will deliver up to 100W no problems, figuring out the cut off voltage is a little bit fiddly, I found that starting with a battery that isn't fully charged is a good way to start, after it's first few charge cycles, you can turn up the cutoff voltage to get it to where you want it to be, but once it's set, you will probably keep checking it a few times a day to begin with and later to once a day to once every few days till you just forget about it because it just works! And it needs nothing!
If you have more battery capacity than you actually need to use, in other words, you have enough energy storage to keep whatever you are running off it to keep running for more than two or three days without sunshine, then you won't have to worry about the batteries going into protection due to under voltage...
The batteries that I'm using are those 8Ah types that are usually used in computer ups power backup thing's, they are expensive per Ah but cheaper as a 12V complete battery that I don't have to build myself and it's protected against everything and has a built-in balancer! At $66Au each, I can purchase one a week and wouldn't notice it out of my pay!
I hope that this helps...
@@PeterMilanovski I never knew you could wire them up in parallel, I need to handle 6A so I could just use 3 of these right?
@@kaikart123 that's correct! With 10 of these I get a 1Kw... They do get pretty warm but with a computer fan also connected to the solar panel, it fire's up when the panel wake's up and shuts down when the panel goes to sleep which means that it's only working when it's needed, a diode in series with the fan and some capacitors after the diode will delay the fan turn off time, more capacity, more running time! That's just an idea though, if you are going to be using them at their 100W maximum rating, it wouldn't hurt to have some active cooling, either way, it has electrolytic capacitors on it and it's always best practice to keep them as cool as possible for long service life, capacitors next to a heat source always fail first before others that are further away from the heat source...
Can you put power from the battery whilst it’s charging?
Wouldn't the combination of the adjustable controller and a balance board constitute a BMS?