This Channel offers great Value! Luving it!

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

Your clear and well illustrated explanation is very much appreciated; thank you!

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.

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 !

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.

@arijunal

3 жыл бұрын

This is the answer I was looking for. Thanks

@PeterMilanovski

3 жыл бұрын

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!

@milvolts1

3 жыл бұрын

@@PeterMilanovski , not to mention their price. Shout out to Mr. Welch. Thanks to him we were able to fill our needs

Very helpful and informative review. Thank you for your time.

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

@PeterMilanovski

3 жыл бұрын

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!

@andthesunsets

2 жыл бұрын

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.

Such a great find 😊 thank you

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.

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.

@chrisw1462

4 жыл бұрын

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.

@ahaveland

4 жыл бұрын

@@chrisw1462 It's an MPP controller without the T.

@chrisw1462

4 жыл бұрын

@@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.

@ahaveland

4 жыл бұрын

@@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.

@chrisw1462

4 жыл бұрын

@@ahaveland If it's not tracking, it's not Maximum anything.. :-)

very nice video sir. super, neat and clear explanation. keep spreading knowledge.

very nice explainations and clear voice! thx

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 learned a lot. thanks for posting

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 !

@DavidKaden369

4 жыл бұрын

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.

@2cyclebikeraricstreet195

2 жыл бұрын

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

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.

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!

Great comparison

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.

@AdamWelchUK

7 жыл бұрын

Useful info - thanks very much.

@joeboxter3635

7 ай бұрын

@@AdamWelchUK Yes, but you have a 12V panel at 10W. So not surprised they designed it to operate at 17V - 18V Vmp.

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?

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 :-)

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 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.

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!

@AdamWelchUK

8 жыл бұрын

+pepefpv Glad to be of service!

@nathan100tz

8 жыл бұрын

+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?

@AdamWelchUK

8 жыл бұрын

+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.

@nathan100tz

8 жыл бұрын

+Adam Welch Awesome, thanks!

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.

@PeterMilanovski

3 жыл бұрын

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 💖.

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.

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.

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

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.

@PeterMilanovski

3 жыл бұрын

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...

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.

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?

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.

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.

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

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?

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.

very nice info

@AdamWelchUK

7 жыл бұрын

+jehugarcia Thanks Jehu.

@caserio323

6 жыл бұрын

Garcia papa tu me apareses hasta en las sopas lol

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...

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.

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.

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?

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?

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.

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!

nice video! what make power inverter in the 400 watt range would you recommend?

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 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?

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

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.

@AdamWelchUK

7 жыл бұрын

+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.

@mjp0815

7 жыл бұрын

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.

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!

@2cyclebikeraricstreet195

2 жыл бұрын

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

@2cyclebikeraricstreet195

2 жыл бұрын

I think it's like 13.1V

great job ! ;-)

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

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.

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.

LOL! A "book" converter! You plog in a book and the movie comes out!

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....

You would need a boost controller to 13.4v for lead & gel 12v batteries.

great videos! Is there a way of solar charging a 48v ebike battery while you drive the bike?

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 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.

@cameraman1234567890

8 ай бұрын

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!

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.

@PeterMilanovski

3 жыл бұрын

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...

@iceberg789

3 жыл бұрын

@@PeterMilanovski ah, you reminded me some very old stuff. 😁

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.

@nathan100tz

8 жыл бұрын

heat shrink tube

Sorry I got exited going to max volts made the second 1 more Efficient my bad you're awsome!!!!

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.

At 28V max in, you can't use the large cheeper panels around 30-40Vmp.

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?

My waterfall was powering up great. Until I messed around with the potentiometer of the battery voltage. It powers off my devices. Then after disconnecting battery and reconnecting it works again. Its been doing it regularly. Is there a way to reset the mppt to its normal state?

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.

As to u have shown this it’s nice but would like to know if any 6V3W circuit is there for

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.

@AdamWelchUK

7 жыл бұрын

I'll see what I can do, but I've got a few things on my list to compete first.

@Hemewl

7 жыл бұрын

Thanks! Perhaps I'll beat you to it :-D

can we use 11.1 V, 13AH lithium ion battery which has 8 cell in the pack?

Very interesting @ 12:40 min by decreasing the mpp Voltage of the panel the output power is rising.

ty for this video :)

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?

is it possible to extend an mppt controller/hybrid inverter PV input voltage? Perhaps just upgrading the input stage capacitors? I noticed a voltage divider network near the 100v 1000uF im guessing it reports the input voltage to the mcu. My mppt/inverter is a Easun Power ISolar SMV 3k 24v

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?

Hi Adam. I have been following your channel for sometime now and have possibly made a mistake with selecting an alleged MPPT solar controller. The charge controller I have does not have any identified model numbers. Allegedly the controller is capable at 40 amps, max pv of 50v with a max pv input of 520w (12v). The display went off, it through everything off and never came back on. So I opened it up then noticed some strange things. There was identified mppt controller ic. There seems to be 2 chips one identified as made by HOLTEK, then another ic with no chip id. So I have serious doubts about weather it is a true MPPT charge controller. The board has an id of XW-LVD01-V2.0. There is no resistance on the solar input. Any advice would be much appreciated.

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?

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.

@AdamWelchUK

7 жыл бұрын

+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.

Thanks for the video, interesting little parts. May I inquire as to where you got those Watt Meters?

@AdamWelchUK

7 жыл бұрын

Thanks - Sure, eBay... goo.gl/QfvAeF :-)

@patrickmacmillan

7 жыл бұрын

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

@PeterMilanovski

3 жыл бұрын

I saw the input wattage climb to the full 10W when he gets the panel voltage to 18.2V...

thanks!

I was thinking about this I was thinking the one that adjusts I have a 270watt panel 4 629 commercial battery’s I have the perfect suitor one which is supposed to be mppt but isn’t could I just swop that for this thanks tony

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.

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

what do you think I can use to charge a 4S 50ah battery pack with solar? 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.

@AdamWelchUK

7 жыл бұрын

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

I got this charge controller. However, it is showing a green light (meaning fully charged) when my three Li-ion 18650 batteries in series is at a voltage of 10.5V. Full charge voltage is 12.6V. What is the issue and how can I fix it?

Can you put power from the battery whilst it’s charging?

Can the battery be used to power anything while it is charging? Any extra circuit needed? Or just hook it up?

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.

the input can connect with 18-20v solar panel to charge battery?

Thanks.

Wouldn't the combination of the adjustable controller and a balance board constitute a BMS?