I use these to charge 20Ah 48v LiFePO4 packs, from CS6X-300 panels. I set them to ~36v with a 57.6v output at 5A CC. The packs are for my various EV's. The MPT-7210A has lots of tweaks and most importantly, a display. It's very light and inexpensive and lives in my Velo. Good to be able to pull a usable charge from any DC source.
Auto-start works perfectly. tested this at home personally. As long the input voltage is 10V or more and remember to save when: 1) icon is in the "Lock" position 2)"On" is shown above the lock then try turning on and off the input. This also allows me to use a higher voltage panel (18V) to charge my sealed lead acid at 12V tested by me at my own backyard using a 100w 18v panel as of 17 Feb 2017
Nabíjet 18v panelem 12v akumulátor podle vnitřního schema zapojení není možné.. +pol soláru je spojen přes cívku a diodu na výstup + regulátoru. Leda že by mosfet zkratoval řízeně napětí za cívkou tak aby udržel nastavené napětí.
I really like the fact that it uses the solar panels for power. Means it doesnt pull power from the batteries during the night this charge controller works really well for me
Great review of this cool little MPPT boost solar charge controller. Can't wait to try this for using my 160watt marine panel to charge my 48 volt e bike battery.
Excellent video. I like seeing you figure out how the thing works. I am just now testing this unit on my solar power system for interior of my solar powered boat. If anyone is interested see espcatblog where I will be posting my experience with the MPT-7210A among other things.
I thought you were done after pt.2. And now this has really worked out for the best. I have been looking at a UPS for my server and PCs which naturally run continuously. And during the wind storms which we are getting much more often that cause outages, I must be able to keep the lights on for several hours. Have 2 x 300 watt panels here to make use of. This might be just the ticket for one of the components.
I just ordered one. I have two 24vdc inverters that are brand new and I have only tried them to see if they work. They are old school and heavy duty. With the boost charge here I can keep the dual 12v batteries charged enough to have back up power. Now I have to keep your videos on tap, so I can try to learn how to program it. Thanks for the instructions.
These LTC Buck Boost converters are awesome, you can add your own logic level MOSFETS and a better heatsink and you have a wide voltage and a big current source. Basically the only thing that you need is +5V input voltage for the logic level MOSFETS and there you go
Many users are reporting unexpected low charging currents. I faced the same and these issues can be easily explained. I did some in dept investigations to find the root cause and here is what I found: This controller cannot accept more than about 6.5A (my observation) as input current. That's how it must have been designed. So the maximum available input power in Watt is: Vin x 6.5A which determines the available charging power. If more charging power (charging Voltage times charging Current) is needed, it can only be archieved by increasing the input voltage Vin when the input current is at its max. Normally a boost converter would increase the input current to keep track of the requested output power but when it reaches 6.5A it's over and out with this device. It's a undocumented limitation. For me it means that I can't charge my 42V ebike battery with more than about 1.7A with a 12V battery as power source. There is a 'workaround' however (don't laugh): connect a decent boost converter on the input of the MPT-7210A to increase the input voltage ... I told you: dont laugh! :-D
wish it had higher solar input... panels are getting super light these days .. you can add series and do it buck converter as well... i m watching a newer mppt 230v dc in for 90+ volt batteries too
I'm not an electrician, nor do I have profound electrical knowledge, but your explanations made it simple for me to understand. This controller will be perfect for what I am doing: setting up one small 20 watt solar panel (output of 17.5V) to charge my 48V li-ion battery on my recumbent tricycle's e-assist motor. I'll be able to take along the solar panel on a small bike trailer and have power when ever I need. If I take along a couple of small 12 volt batteries connected in series and attached to the panel all day, I will have power, via a small inverter, to fire up a blender for Margaritas at night. A win-win; thanks for posting. P.S. Just kidding about the blender, but there are many possibilities.
Hi, how is this working out on your recumbent, as I am setting up the same for my Moulton bicycle, with a trailer. I won't be using a blender though, maybe m hairicurlers lol.
@@velokernow3696 Still working it out. Currently using a back battery scenario, but ideally would love to be able to charge a battery via solar panel while riding with the first battery. Just completed a one-day turn around camping trip which was fun.
will it step down voltage if the input is too high for the battery charging voltage? or will this only boost up voltage? you mentioned it not being good for 12V batteries - does it not work at all for 12V or is it just less efficient?
Great tutorial, does this truly limit the output current? What would happen for example if you set the current output limit to 1A but was drawing 5A, does it just shut down or clamp the limit to 1A. Great work keep it up, cheers.
I'm having an issue with mine. Might be similar to the ramp up and down issue you showed in this video. I'm trying to charge a 36v lithium ion battery, with a charging voltage of 42v. Input is a 120w solar panel that outputs at 20v. When connected, listed battery voltage will climb and the input voltage drops to half; until it hits a certain point, where the battery voltage drops quickly while the input voltage climbs back up to max. This repeats in cycles, with a full cycle taking five seconds. Is this normal?
These can work with a 12V system. Simply add 3 B3603s to the output of the 7210A. You then have a boost-buck setup by having the output of the 7210A at say 24V and the output of the 3603s at 13.8 to 14.1. I watched 100 watts go thru mine that way the other day.
Julian, you could do a rough measurement of your unregulated wall wart's maximum power point by hooking it to an electronic load. Vary the load current and observe its output voltage until you find max power. Compare that result to what this charge controller is doing and you'll know whether it's capable of anything like true MPPT.
"Working modes: MPPT and DC-DC selectable, MPPT for photovoltaic panels application and DC-DC for boost power supply". I pulled that from ebay description. I was thinking that the reason the solar panel input is adjustable is because its in dc-dc mode. Have you tried any hidden commands while in the VIn selection mode?
I studied the manual & couldn't figure out the auto powerup settings, you provided a lot of other useful information also that wasn't obvious in the manual. Thanks for making this video. Disregard the haters BTW, I'm guessing the behavior you saw when you dialed down the panel voltage setting to 8v was due to the MPPT algorithm failing at an unworkable setting.
Happy to see new videos being posted from you again. I hope you had an enjoyable holiday, or 'vacation' for my fellow Americans who are about to be screwed come November
So could I use one of these to charge an E-bike battery 36v? I'm only looking at just over 1 amp and what kind of solar set up would I need ie volts or wattage? I've learnt a lot through these video's but its better to double check.
I have a 36 volt battery for a 4 wheel peddle bike with an e-bike motor. If I understand you correctly, I can use a 12 volt panel with this charge controller set for 36 volts and it will charge the battery completely. Is this correct?
I got two of them. They work fine to charge 12volt batteries.... not sure why everyone is claiming it dont. With out hooking it up and doing it for yourself.
What was the voltage of the solar panel you used? What values did you set the settings at from the top to bottom of the mpt-7210a monitor? Thanks in advance.
Just bought one. All those cool options made it worth it. Now to see if those options really work. I don't care if it's not MPPT. Some of the $150.00 MPPT controllers aren't MPPT either. Can't wait to test it out.
You mean you bought one of the booster controllers and didn't test it before you posted here? Plus didn't follow up whether it worked or worked well enough? What a tease ! LOL
Could the solar panel voltage be the one you set to the solar panel's rated voltage? For example a 12v solar panel is often 17.5v rated voltage and open circuit 20v, so you'd set it to 17.5v so it can extract maximum power at that known voltage?
This, it's the panels mppt voltage normally shown on the panels specs, setting this to the solar panels mppt voltage normally around 17 volts for a 12 volt panel gives best performance, however there is a caveat, boosting the voltage, eg voltage out being higher than voltage in will reduce this performance dramatically.
Very informative video. Question ! I have a solar panel connected to my charge controller then to my 12v battery then a load from my battery to a pump. Can I put charge leads onto my battery via mains electric without disconnection the charge controller and solar panel ? Cheers
Hi Julian, may I ask what you are using to connect the screw terminals on the charge controller to the screw terminals on the female DC connector? Perhaps they are long pin headers? Seems like a really clever method instead of wires!
It's true MPPT for like 50 AUD, pretty awesome. There are long ones called EPEVER and they are up to 40A also and are MPPT for like 100 AUD, my father has one (he has the 20A model). I tested it and also looked inside it and it's a real MPPT also. I myself am looking at some 60A different models and am wanting to run a 24V array of panels, 200w x 8. So I have two sets of 4 in parallel, the two sets together making 24v. This puts the amp input at about 43A or so at max. So it's within operating levels. I have narrowed it down to 3 controllers on ebay, all from $200-$300. I already have a 1500w sine wave inverter off ebay for a few hundred dollars and it has been working lovely for like 5 years now, it runs my computer all day from just 1 200w solar panel.
Hi Julian, my Ming He MPT-7210A has packed up, can I send it to u for one of your repair videos. It doesn't output any power on the battery charging side. Perfect for one of your repair videos. If you can repair it, its fine for me if not, I will get a new one. Thanks
Hi Julian, thanks for this in-depth look at the circuit board and components. Do you happen to know the inductance of the inductor for the boost side of the circuit?
Would you say after tinkering around with this that it's reliable for unattended applications? I'm setting up a system on the roof of a guest house were it's not really convenient to service, and I'd prefer not to lose voltage by running excessive length of cable before the booster. The ability to boost up to 90v really makes this interesting when you need long runs of cabling. Love your vids btw ^^
On the other hand, that LTC3780 board you had works passably as a pseudo MPPT charge controller all on it's own... if you want to charge with CC/CV as you would for a Lithium battery, then you can set those on the CC and CV pots, and if you set the UV pot to the Vmp for your solar panel then as long as the power curve is not jagged then the "under volt" ramp down will give some approximation of MPPT. Perhaps you could make a video testing that board in that mode, since it seems to me it could be quite good.
Hi Jilian, I am getting conflicting issues, as to what the max the set the maximum voltages to set the controller. some hame said 13.8v some 14.1 and so on. what would you recommend I have a 110ah leisure battery and 200wt solar panels on the roof of my van as am a van dweller... Thanks in advance. My controller is a MPPT T20.
F typically refers to frequency (probably using to test the crystal frequency for QC purposes). it appears to be a port for programming the Microcontroller.
After viewing your videos, I bought and use this 7210A controller believe to be boost converter. Question. I have 65 watts solar panel supposed to give 5 Amps. I am charging a 12v battery while trolling my kayak. Using this 7210 I get only 250 mili ah after one hour changing. I never see more than 1.5 A constant current charging. Only around 1.7 watts charged. Panel voltage around 13.3 volts and battery voltages is around 12.75 volts. About half a volt difference always. I never see the 5 Amps rated from the panel which is around 18.5 volts open circuit. Just can not get my 5 Amps from panel to the 12 batteries. Why??? Since you know best, please explain.
Hi, Mr. Julian! Thank you for your videos. I bought one of this MingHe mppt charge controller but I am a bit lost. I gave two 12volts 70amps each hooked in series and it is reading that my batteries are now 30volts. Could it harm my batteries? Would it be possible for you to give me the instructions of how to configure it. What number to put in voltage Amps and a/h and watts. I see that where there is a battery icon on the right side it goes only to yellow and never the green light that completes the battery icon. Thank You! Best regards, Emmanuel Távora Freire
"Long press set, turn the next line", translates to "Hold set to go to next line". The step you showed to get to the other alterable parameters (like screen timeout, on/off, lock status). Also one of the current sensing shunts looks to be in the source lead of the switching mosfet of the boost converter - that would be for power control and protection on a per cycle basis.
Julian, could you post a ranked list of all the mppt charge controllers you have reviewed, with cost, power handling, buck boost or both, quality, etc.
Great job! Left one connected to my E Class to charge my cars brand new Bosch 12 v AGM battery for 3 month. Sadly my car battery went flat with only 2 volts left! I recharged my battery with brand new 10A charger for AGM battery n it took nearly 2 days. Your 3 videos has helped me to understand how this device can work each morning when our weak sun comes out. Will try resetting the device so it comes on in morning. Maybe our battery might get the juice it needs without going flat again
Hi Julian, this is a great mppt solar charger ( the cheapest that really works reasonably well) but it is a boost converter. Do you know if mingHe manufactures something similar in buck topology? as always, excellent review !!! thanks
Great videos I have a 72 volts battery bank in my sailboat..what will be the set up you’ll put to charge? I’m referring to the input voltage for a 72 volts output Thanks
I tried an interesting experiment with this controller. I put a 13.6V 10A regulated power supply on the input side and tried to charge a 48V battery bank. It worked but I only got about 40 watts of charge power (even when the bank was loaded with 100+ watts). I even turned up the output voltage on the power supply to see if I could get more "juice" from the SCC but it refused to go much past 40 watts which I find rather odd since the PS can output probably close to 150W max. What happened to the other 110W or so? For my next test, I will use a variable voltage (0-30V) output PS (3A max), and see at which input voltage (to the SCC) gives maximum output. For example, I will first try 12V output of the PS, then 18V, then 24V, then 30V, always pre-adjusting the first voltage on the SCC (the pseudo-MPPT solar voltage), and observe the output wattage into a 48V 100Ah battery bank. If the output wattage changes disproportionately to the input wattage (the PS shows me both voltage and amperage so I can easily compute wattage), then some basic conclusions can be drawn about the efficiency of this SCC at different input voltages. I will test this out in the next week or so and report back here.
Unlike most thing you feature in post-bag... I managed to buy this one before I saw your video! I came to basically all the same conclusions. Took me quite a while to figure everything out because of the terrible as usual "manual". As someone else here said... It does seem to be MPPT, but is very slow to react and has a really hard time on a day with clouds moving through. Lots of resets. As for the panel voltage field... Still wondering, but I've have good luck setting it just a few volts below my 25W panel's MPP of 18.8. Will be hooking up some more panels soon. I'm hoping to use this to keep some lead charged up and run the fridge in my home with my 48V sine wave inverter.
This is a probably late much after you've done this video but I believe that that particular charge controller the green one is a charge controller that doesn't need a battery that he can go right into a component, meaning that that charge controller can charge strictly off of solar if you do another video check this feature out.
Great videos Julian, thanks. What are your thoughts about this charge controller. HQST 20A 12/24V MPPT Solar Charge Controller. If ordered on Amazon during July 2020 it includes the LCD display, only $45 US with display. Anyone else have thoughts?
Hi Julian, I got mine from Amazon for £25.99. I'm going at add an external 5V USB PSU to either the input or output of the 5V regulator so that the unit does not turn off at night or during a heavy load with weak sun.
i have the same charge controller, but my screen always shows the amps, watts, and watt/amp hours at 0...no fluctuation of any kind..... and the left battery bar is empty as well... got any advice to make it work? your vids have helped the most so far, so i figured id ask.
Hello , I didn't study the video of the Ming he mppt but was wondering if you set the upper watts parameter in yellow to the wattage of the panel would it then come on automatically?
Could this be used without the function for charging batteries to 1- improve the yield from solar panels 2- place a load instead of the battery charging. Will it take 4-solar panels of 315 watts or is this too much?
After I watched all 3 videos I was thinking if I could use this unit to charge 2 pcs of 12V lead acid batteries connected in series with maybe a re-purposed laptop battery supply. Would I need to worry about the balancing of the two batteries? Or it is not an issue with lead acid?
If the 2 lead acid batteries are new then you will be ok. Periodically an equalisation charge would restore balance which of course this charge controller could achieve with ease by cranking up the set voltage to say 31-32volts for 24v wet lead acid. Dont do this with VRLA/AGM batteries and certainly not with GEL
Gareth S Ah, thanks for the clarification. I have two ZAP Energy Plus Marine battery. I think these are the AGM types, although it is not clear for me. Just to make sure I understand your correctly: I can charge them together, but do not crank up the set voltage, just keep it at 24V. Correct?
can this be used for charging from a 12 battery. to a higher volt battery. and not use solar. the reason I ask. I built some DC lamps both battery backup . with lithium cells. 6- 26650 cells. with 2- 12v LED's in series. and looking to charge them from my 12 v solar batt bank. I have a few of them. should I just get a dc-dc and BMS.? or just re configure for 12v and use a small charge controller?
Could it be both MPPT and PWM and a lodgic circuit tells it too sorta pulse when the demand is low and supplyvoltage is high with sorta bursts of power?
Question please: I have this device powered by a 20 watt solar panel from which I can get 22 watts in the sunshine. From there I am charging a 48V 17.5Ah li-ion battery. Problem is that I can barely get much amperage flow. During charging it's showing a amp rate of .18, not even 1 amp. Is that because the battery is already near fully charged state? Do I need more power from the panel? Perhaps boost up the amps allowed while programming? I would love to get at least 2 amps, Any ideas?
11:57 - Maybe that voltage setting tells the MPPT circuitry to "hover" around that value since it is known for each panel what Vmpp is. For example, if I know Vmpp is 40.0V on my panel, there is no point it having the solar charge controller (scc) check 50.0V and also no point in checking 30.0V. Perhaps it is a starting point so the MPPT algorithm can try voltages close to that value. I have one of those sccs here so I will play around with it and see what happens if I purposely set it too low or too high. My guess is it will take the MPPT algorithm longer to find the ideal value since it may "waste time" trying values that are too far away from the actual ideal voltage.
Hi. Thanks for the videos. Would you help me with something?, i have unlimited ammounts of ebikes batteries 36v, i bough the MPT-7210A, hoping it will charge the batteries which it seems thanks to your videos that it will. The problem i have now is in finding a 36v inverter to 240v ac, i am in the UK. Thanks in advance.
This unit is ok for charging batteries but not ideal. This is because it is not a multistage charger that can be programmed for different voltages using the same setting. For example, if I want to let it charge a 36V golf cart as high as 43V during the bulk charging phase, then have it back off to 41V for the maintain phase, I don't see a way to do that other than programming both of those settings and then manually changing it after it finishes the 43V stage.
need your help again, please! Here in Israel outside is 45 degrees Centigrades and I am a little warried. Please look at the pictures and give me an advise and tell me if I should be warried and what I should do. The charger shows that the two batteries are more than 30 volts as you see in the voltmeter and I measured the two together and each one. And the other device says the each battery is full and has the red light of alternator lit but this electric car has no alternator. The green light that shows that the battery is good lights only sometimes. Is this normal? Please help me. Thank You! Best regards, Emmanuel
A combined Buck-Boost converter in a solar charge controler would give you more variablity in the output voltage but on the cost of less overall efficiency! A buck converter can be build very effiecient (up to 98% efficiendy or even more) whereas a buck-boost will be most probably below 85%. This makes a big difference in the whole system and i would always tend to go to more panels in series to get higher voltages to use a buck converter instead of a boost or buck-/boost converter. Even a pure boost converter will normally stay behind the efficiency of a pure buck converter.
I’m not sure why you’d set the battery capacity amp hours... it’s a neat idea, but w/o the device measuring the current draw from the battery, how would it ever know to run AH backwards?
One thing you don't seem to have mentioned is that the solar panel peak voltage must be lower than the fully charged battery voltage. What ever panel/battery combination used. Because if you have a higher voltage panel even if the controller turns off the current will pass through the double diode. So it has to be used in the voltage boost mode. I am also surprised Julian that you don't have a decent bench PSU considering all the videos you do.
Zoony I thought if there are diodes that prevents especially reverse flow of current to the solar panel. By double diode doesn't that mean stopping current forward flow to the battery? Plus this is a controller and it itself is the starting or stoppage of any flow of current backwards or forwards, right?
What about using this with normal panel setup (36 cell, 19v) and 12v battery system in where batteries are charged in series of two (24v or more..) and output is taken by parallel connections onto those batts (12v)?
gelisob i have tried to figure out such a system but can't figure how to do it without blocking diodes. Unfortunately that results in around 3v drop (2 diodes) which I consider unacceptable.
Hello, Why I can't get more charge power than 150W on the mpt-7210a regulator? In full sun, I connect 4x230W solar panels in parallel mpp = 29V Open circuit 40V. The rechargeable batteries are 48V 40Ah. The parameters set in the controller are 55V charging voltage and 10A charging current and mppt set to 29V. The regulator shows the voltage on the PV during charging 35V and the battery charging current 3A and the voltage on the battery 50V. The regulator should draw PV voltage to 29V and give a charging current of 10A which would give 500W.
What is max wattage it can transfer from panels to battery? Ill want to use this with 2x300w panels for start for my barn. And charge ups 24v 2kw in capacity.
That thing looks to be a right pain in the arse to set up! I admire your perseverance, Jules! Please though, fix that bend flange xD Crush it flat in a vice or something. Hold a block of wood over it and hammer it flat ("Where's my 'ammer?") I can't wait to see this eclectic car :D! Solar Freakin' Julian Roadster :D
Brilliant as usual I would love if one day you could test a votronic mppt Duo Digital it’s very good but you’re the best at explaining these so well there are some blogs but they are all German Please please 👉🏿votronic 👈🏿please send this man one to show to the English language Cheers 👍🏿
I should have watched the videos before I bought one of these :) I thought great, a small mppt charge controller to replace the PWM fake i've been using on a 190W panel and 24V system. Never mind. I guess the company had a particular application in mind that needed quantity. There can't be many uses for a boost controller. It would be nice if they made a buck version. I experimented with a small 5A mppt bare pcb buck module but only on a 20W panel. A 10-12A version of the 5A module would be quite handy.
This is a good controller for the money but if they spent £20 more on it they could make it great. Im confused at what the solar panel voltage ajustment does exactly? Im pretty sure it uses P&O method to track, which is what you would expect. The microprocessor outputs a variable duty cycle 1.95KHz PWM on two digital pins, one goes through a 3 stage RC filter and then into an op-amp. The other digital output goes through a 2 stage RC filter and then through an op amp follower. These two signals manipulate the voltage on the boost controller IC (UCC3803) FB and CS pins to get the controller to behaves how it wants. Problem is these RC filters introduce huge signal propergation delay (60ms for the 3 stage). So the micros new 'instruction set' takes an electronic age to reach the UCC3803 and before the controller can adjust the duty cycle to react to a quick irradiance shift the controller crashes and goes into a soft start cycle. -_- In layman terms - The controller trips over its own feet when there is a sharp irradiance change due to its slow nervous system.
Hi i am trying to setup small DIY solar project. I have 12 W!/40V solar panel. I want to charge 12 V battery. How can I set up economic charge controller? Most charge controllers are low voltage rating and PWD where we lose lot of energy in DC step down. What is your suggestion? Thanks
I use these to charge 20Ah 48v LiFePO4 packs, from CS6X-300 panels. I set them to ~36v with a 57.6v output at 5A CC. The packs are for my various EV's. The MPT-7210A has lots of tweaks and most importantly, a display. It's very light and inexpensive and lives in my Velo. Good to be able to pull a usable charge from any DC source.
Thank you so much for posting this about the menu flow and esp setting it to a constant on state. Very helpful and much appreciated.
Some listings for this item on eBay show two operating modes. MPPT and DC-DC. Have you figured out "How to change between these two modes" ?
Auto-start works perfectly. tested this at home personally. As long the input voltage is 10V or more and remember to save when:
1) icon is in the "Lock" position
2)"On" is shown above the lock
then try turning on and off the input.
This also allows me to use a higher voltage panel (18V) to charge my sealed lead acid at 12V
tested by me at my own backyard using a 100w 18v panel as of 17 Feb 2017
Nabíjet 18v panelem 12v akumulátor podle vnitřního schema zapojení není možné.. +pol soláru je spojen přes cívku a diodu na výstup + regulátoru. Leda že by mosfet zkratoval řízeně napětí za cívkou tak aby udržel nastavené napětí.
I really like the fact that it uses the solar panels for power. Means it doesnt pull power from the batteries during the night this charge controller works really well for me
Great review of this cool little MPPT boost solar charge controller. Can't wait to try this for using my 160watt marine panel to charge my 48 volt e bike battery.
Excellent video. I like seeing you figure out how the thing works. I am just now testing this unit on my solar power system for interior of my solar powered boat. If anyone is interested see espcatblog where I will be posting my experience with the MPT-7210A among other things.
I love this unit. I use it to charge my 36v ebike battery. That being said, the up (boost only) functionality drives me nutz.
how many watts are your panel, and how many A can you charge it with?
I thought you were done after pt.2. And now this has really worked out for the best. I have been looking at a UPS for my server and PCs which naturally run continuously. And during the wind storms which we are getting much more often that cause outages, I must be able to keep the lights on for several hours. Have 2 x 300 watt panels here to make use of. This might be just the ticket for one of the components.
I just ordered one. I have two 24vdc inverters that are brand new and I have only tried them to see if they work. They are old school and heavy duty. With the boost charge here I can keep the dual 12v batteries charged enough to have back up power. Now I have to keep your videos on tap, so I can try to learn how to program it. Thanks for the instructions.
An inverter is not a battery needing to be recharged, correct?
These LTC Buck Boost converters are awesome, you can add your own logic level MOSFETS and a better heatsink and you have a wide voltage and a big current source.
Basically the only thing that you need is +5V input voltage for the logic level MOSFETS and there you go
Many users are reporting unexpected low charging currents. I faced the same and these issues can be easily explained. I did some in dept investigations to find the root cause and here is what I found:
This controller cannot accept more than about 6.5A (my observation) as input current. That's how it must have been designed. So the maximum available input power in Watt is: Vin x 6.5A which determines the available charging power. If more charging power (charging Voltage times charging Current) is needed, it can only be archieved by increasing the input voltage Vin when the input current is at its max. Normally a boost converter would increase the input current to keep track of the requested output power but when it reaches 6.5A it's over and out with this device. It's a undocumented limitation. For me it means that I can't charge my 42V ebike battery with more than about 1.7A with a 12V battery as power source.
There is a 'workaround' however (don't laugh): connect a decent boost converter on the input of the MPT-7210A to increase the input voltage ... I told you: dont laugh! :-D
wish it had higher solar input... panels are getting super light these days .. you can add series and do it buck converter as well... i m watching a newer mppt 230v dc in for 90+ volt batteries too
I'm not an electrician, nor do I have profound electrical knowledge, but your explanations made it simple for me to understand. This controller will be perfect for what I am doing: setting up one small 20 watt solar panel (output of 17.5V) to charge my 48V li-ion battery on my recumbent tricycle's e-assist motor. I'll be able to take along the solar panel on a small bike trailer and have power when ever I need. If I take along a couple of small 12 volt batteries connected in series and attached to the panel all day, I will have power, via a small inverter, to fire up a blender for Margaritas at night. A win-win; thanks for posting.
P.S. Just kidding about the blender, but there are many possibilities.
Hi, how is this working out on your recumbent, as I am setting up the same for my Moulton bicycle, with a trailer. I won't be using a blender though, maybe m hairicurlers lol.
@@velokernow3696 Still working it out. Currently using a back battery scenario, but ideally would love to be able to charge a battery via solar panel while riding with the first battery. Just completed a one-day turn around camping trip which was fun.
will it step down voltage if the input is too high for the battery charging voltage? or will this only boost up voltage? you mentioned it not being good for 12V batteries - does it not work at all for 12V or is it just less efficient?
Great tutorial, does this truly limit the output current? What would happen for example if you set the current output limit to 1A but was drawing 5A, does it just shut down or clamp the limit to 1A. Great work keep it up, cheers.
I'm having an issue with mine. Might be similar to the ramp up and down issue you showed in this video.
I'm trying to charge a 36v lithium ion battery, with a charging voltage of 42v. Input is a 120w solar panel that outputs at 20v.
When connected, listed battery voltage will climb and the input voltage drops to half; until it hits a certain point, where the battery voltage drops quickly while the input voltage climbs back up to max. This repeats in cycles, with a full cycle taking five seconds.
Is this normal?
These can work with a 12V system. Simply add 3 B3603s to the output of the 7210A. You then have a boost-buck setup by having the output of the 7210A at say 24V and the output of the 3603s at 13.8 to 14.1. I watched 100 watts go thru mine that way the other day.
Do you have a schematic for your idea gravelyfon?
Julian a million thanks. Following your instruction I was able to set my Mppt controller. It took me a while. Thanks again
Julian, you could do a rough measurement of your unregulated wall wart's maximum power point by hooking it to an electronic load. Vary the load current and observe its output voltage until you find max power. Compare that result to what this charge controller is doing and you'll know whether it's capable of anything like true MPPT.
"Working modes: MPPT and DC-DC selectable, MPPT for photovoltaic panels application and DC-DC for boost power supply".
I pulled that from ebay description.
I was thinking that the reason the solar panel input is adjustable is because its in dc-dc mode. Have you tried any hidden commands while in the VIn selection mode?
I studied the manual & couldn't figure out the auto powerup settings, you provided a lot of other useful information also that wasn't obvious in the manual. Thanks for making this video. Disregard the haters BTW, I'm guessing the behavior you saw when you dialed down the panel voltage setting to 8v was due to the MPPT algorithm failing at an unworkable setting.
would have been nice to see the change in amps like another reviewer does to see the efficiency of it with power analyzers...
Why they just pay you to do documentation? They probably figure, why bother writing good documentation when we have Julian
Happy to see new videos being posted from you again. I hope you had an enjoyable holiday, or 'vacation' for my fellow Americans who are about to be screwed come November
Hi Julian, thanks for sharing, just what I'm looking for. Are you still you using this product? Best regards, Edward
Excellent investigation, exploration, explanation. Thank you.
So could I use one of these to charge an E-bike battery 36v? I'm only looking at just over 1 amp and what kind of solar set up would I need ie volts or wattage? I've learnt a lot through these video's but its better to double check.
I have a 36 volt battery for a 4 wheel peddle bike with an e-bike motor. If I understand you correctly, I can use a 12 volt panel with this charge controller set for 36 volts and it will charge the battery completely. Is this correct?
Nice series of videos. I've used cheap (1$) 2A Buck converter for my DIY 9V 14W solar panel to charge my Lipo pack with TP4056, it works really well.
I got two of them. They work fine to charge 12volt batteries.... not sure why everyone is claiming it dont. With out hooking it up and doing it for yourself.
What was the voltage of the solar panel you used? What values did you set the settings at from the top to bottom of the mpt-7210a monitor? Thanks in advance.
Just bought one. All those cool options made it worth it. Now to see if those options really work. I don't care if it's not MPPT. Some of the $150.00 MPPT controllers aren't MPPT either. Can't wait to test it out.
You mean you bought one of the booster controllers and didn't test it before you posted here? Plus didn't follow up whether it worked or worked well enough? What a tease ! LOL
Could the solar panel voltage be the one you set to the solar panel's rated voltage? For example a 12v solar panel is often 17.5v rated voltage and open circuit 20v, so you'd set it to 17.5v so it can extract maximum power at that known voltage?
This, it's the panels mppt voltage normally shown on the panels specs, setting this to the solar panels mppt voltage normally around 17 volts for a 12 volt panel gives best performance, however there is a caveat, boosting the voltage, eg voltage out being higher than voltage in will reduce this performance dramatically.
Very informative video. Question ! I have a solar panel connected to my charge controller then to my 12v battery then a load from my battery to a pump. Can I put charge leads onto my battery via mains electric without disconnection the charge controller and solar panel ? Cheers
Hello, thanks for your video, could you tell me if the mppt 7210A could charge a 72v LiFePo4 battery? (100% at 84v) thanks
Hi Julian, may I ask what you are using to connect the screw terminals on the charge controller to the screw terminals on the female DC connector? Perhaps they are long pin headers? Seems like a really clever method instead of wires!
It's true MPPT for like 50 AUD, pretty awesome. There are long ones called EPEVER and they are up to 40A also and are MPPT for like 100 AUD, my father has one (he has the 20A model). I tested it and also looked inside it and it's a real MPPT also.
I myself am looking at some 60A different models and am wanting to run a 24V array of panels, 200w x 8.
So I have two sets of 4 in parallel, the two sets together making 24v. This puts the amp input at about 43A or so at max. So it's within operating levels.
I have narrowed it down to 3 controllers on ebay, all from $200-$300. I already have a 1500w sine wave inverter off ebay for a few hundred dollars and it has been working lovely for like 5 years now, it runs my computer all day from just 1 200w solar panel.
Hi Julian, my Ming He MPT-7210A has packed up, can I send it to u for one of your repair videos. It doesn't output any power on the battery charging side. Perfect for one of your repair videos. If you can repair it, its fine for me if not, I will get a new one. Thanks
Hi Julian, thanks for this in-depth look at the circuit board and components. Do you happen to know the inductance of the inductor for the boost side of the circuit?
I don't remember seeing a schematic for this device - so no, sorry :(
Would you say after tinkering around with this that it's reliable for unattended applications? I'm setting up a system on the roof of a guest house were it's not really convenient to service, and I'd prefer not to lose voltage by running excessive length of cable before the booster. The ability to boost up to 90v really makes this interesting when you need long runs of cabling. Love your vids btw ^^
One thing I forgot to mention - this controller is rebooted daily! That will surely make it more reliable.
On the other hand, that LTC3780 board you had works passably as a pseudo MPPT charge controller all on it's own... if you want to charge with CC/CV as you would for a Lithium battery, then you can set those on the CC and CV pots, and if you set the UV pot to the Vmp for your solar panel then as long as the power curve is not jagged then the "under volt" ramp down will give some approximation of MPPT.
Perhaps you could make a video testing that board in that mode, since it seems to me it could be quite good.
Hi Jilian, I am getting conflicting issues, as to what the max the set the maximum voltages to set the controller.
some hame said 13.8v some 14.1 and so on. what would you recommend I have a 110ah leisure battery and 200wt solar panels on the roof of my van as am a van dweller... Thanks in advance. My controller is a MPPT T20.
F typically refers to frequency (probably using to test the crystal frequency for QC purposes). it appears to be a port for programming the Microcontroller.
Hi Julian, could you give the information of its quiescent current? How much mA does the device consume at no load, say with a 18V input?
would you mind testing that with a 4S 18650 pack and see how it does im looking for options thanks
Thanks for the thorough review. I really appreciate it
After viewing your videos, I bought and use this 7210A controller believe to be boost converter. Question. I have 65 watts solar panel supposed to give 5 Amps. I am charging a 12v battery while trolling my kayak. Using this 7210 I get only 250 mili ah after one hour changing. I never see more than 1.5 A constant current charging. Only around 1.7 watts charged. Panel voltage around 13.3 volts and battery voltages is around 12.75 volts. About half a volt difference always. I never see the 5 Amps rated from the panel which is around 18.5 volts open circuit. Just can not get my 5 Amps from panel to the 12 batteries. Why???
Since you know best, please explain.
Hi, Mr. Julian!
Thank you for your videos.
I bought one of this MingHe mppt charge controller but I am a bit lost. I gave two 12volts 70amps each hooked in series and it is reading that my batteries are now 30volts. Could it harm my batteries? Would it be possible for you to give me the instructions of how to configure it. What number to put in voltage Amps and a/h and watts. I see that where there is a battery icon on the right side it goes only to yellow and never the green light that completes the battery icon.
Thank You!
Best regards,
Emmanuel Távora Freire
What is that black adapter called that is letting you plug in a standard wall power supply into the input of the MPT-7210A?
"Long press set, turn the next line", translates to "Hold set to go to next line". The step you showed to get to the other alterable parameters (like screen timeout, on/off, lock status). Also one of the current sensing shunts looks to be in the source lead of the switching mosfet of the boost converter - that would be for power control and protection on a per cycle basis.
Julian, could you post a ranked list of all the mppt charge controllers you have reviewed, with cost, power handling, buck boost or both, quality, etc.
Great job! Left one connected to my E Class to charge my cars brand new Bosch 12 v AGM battery for 3 month. Sadly my car battery went flat with only 2 volts left! I recharged my battery with brand new 10A charger for AGM battery n it took nearly 2 days. Your 3 videos has helped me to understand how this device can work each morning when our weak sun comes out. Will try resetting the device so it comes on in morning. Maybe our battery might get the juice it needs without going flat again
Hi Julian, this is a great mppt solar charger ( the cheapest that really works reasonably well) but it is a boost converter. Do you know if mingHe manufactures something similar in buck topology?
as always, excellent review !!! thanks
Great videos
I have a 72 volts battery bank in my sailboat..what will be the set up you’ll put to charge?
I’m referring to the input voltage for a 72 volts output
Thanks
I have a battery bank of 6 12 volts agm batteries in series
Thank you, Sir, for your video really helping me to program this charge controller Thanks
I tried an interesting experiment with this controller. I put a 13.6V 10A regulated power supply on the input side and tried to charge a 48V battery bank. It worked but I only got about 40 watts of charge power (even when the bank was loaded with 100+ watts). I even turned up the output voltage on the power supply to see if I could get more "juice" from the SCC but it refused to go much past 40 watts which I find rather odd since the PS can output probably close to 150W max. What happened to the other 110W or so?
For my next test, I will use a variable voltage (0-30V) output PS (3A max), and see at which input voltage (to the SCC) gives maximum output. For example, I will first try 12V output of the PS, then 18V, then 24V, then 30V, always pre-adjusting the first voltage on the SCC (the pseudo-MPPT solar voltage), and observe the output wattage into a 48V 100Ah battery bank. If the output wattage changes disproportionately to the input wattage (the PS shows me both voltage and amperage so I can easily compute wattage), then some basic conclusions can be drawn about the efficiency of this SCC at different input voltages. I will test this out in the next week or so and report back here.
Hi Julian, I think you could use a buck converter to emulate a 6v or 9v solar panel, and see if that MPPT would be able to charge a 12v battery
Unlike most thing you feature in post-bag... I managed to buy this one before I saw your video! I came to basically all the same conclusions. Took me quite a while to figure everything out because of the terrible as usual "manual". As someone else here said... It does seem to be MPPT, but is very slow to react and has a really hard time on a day with clouds moving through. Lots of resets. As for the panel voltage field... Still wondering, but I've have good luck setting it just a few volts below my 25W panel's MPP of 18.8. Will be hooking up some more panels soon. I'm hoping to use this to keep some lead charged up and run the fridge in my home with my 48V sine wave inverter.
Can you change the battery voltage in small incredements? Or is it in big steps? Like 22v 32v 46v 58v 60v
Would it work with a 13S (50+ volt) Li-Ion Battery pack with BMS? Does it have any cut-off safety besides the capacity limit you set?
This is a probably late much after you've done this video but I believe that that particular charge controller the green one is a charge controller that doesn't need a battery that he can go right into a component, meaning that that charge controller can charge strictly off of solar if you do another video check this feature out.
Great videos Julian, thanks. What are your thoughts about this charge controller. HQST 20A 12/24V MPPT Solar Charge Controller. If ordered on Amazon during July 2020 it includes the LCD display, only $45 US with display. Anyone else have thoughts?
Hi Julian, I got mine from Amazon for £25.99. I'm going at add an external 5V USB PSU to either the input or output of the 5V regulator so that the unit does not turn off at night or during a heavy load with weak sun.
i have the same charge controller, but my screen always shows the amps, watts, and watt/amp hours at 0...no fluctuation of any kind..... and the left battery bar is empty as well... got any advice to make it work? your vids have helped the most so far, so i figured id ask.
Hello , I didn't study the video of the Ming he mppt but was wondering if you set the upper watts parameter in yellow to the wattage of the panel would it then come on automatically?
Could this be used without the function for charging batteries to
1- improve the yield from solar panels
2- place a load instead of the battery charging.
Will it take 4-solar panels of 315 watts or is this too much?
it would be more efficient to have a 18 or 24 solar panel to a 36 volt battery? current is a factor too? overheating of the device?
Set the solar panel voltage to the nominal power output of the panel.
After I watched all 3 videos I was thinking if I could use this unit to charge 2 pcs of 12V lead acid batteries connected in series with maybe a re-purposed laptop battery supply. Would I need to worry about the balancing of the two batteries? Or it is not an issue with lead acid?
If the 2 lead acid batteries are new then you will be ok. Periodically an equalisation charge would restore balance which of course this charge controller could achieve with ease by cranking up the set voltage to say 31-32volts for 24v wet lead acid. Dont do this with VRLA/AGM batteries and certainly not with GEL
Gareth S Ah, thanks for the clarification. I have two ZAP Energy Plus Marine battery. I think these are the AGM types, although it is not clear for me. Just to make sure I understand your correctly: I can charge them together, but do not crank up the set voltage, just keep it at 24V. Correct?
Yes agm should be OK for around 28.8 Usually they will specify a cyclic voltage on the side of the battery and multiply by 2 for the series pair
can this be used for charging from a 12 battery. to a higher volt battery. and not use solar. the reason I ask. I built some DC lamps both battery backup . with lithium cells. 6- 26650 cells. with 2- 12v LED's in series. and looking to charge them from my 12 v solar batt bank. I have a few of them. should I just get a dc-dc and BMS.? or just re configure for 12v and use a small charge controller?
This is perfect, I have been looking for a boost charge controller that can charge my 36v/48v bike batteries using an 18v panel.
This charge controller can buust. :)
Can i get 58v 6amps output by giving 12v 5amps input? If not what would be the minimum input required,
The lower you put the incoming voltage, the lower you can put the maximum voltage for your battery bank, correct?
Could it be both MPPT and PWM and a lodgic circuit tells it too sorta pulse when the demand is low and supplyvoltage is high with sorta bursts of power?
Hi! I have a question.Can I setting manual the MPPT mode or DC-DC mode ,or it is working automatically?
Auto
I just caught up with the video.You answered it.
Thank you
Question please: I have this device powered by a 20 watt solar panel from which I can get 22 watts in the sunshine. From there I am charging a
48V 17.5Ah li-ion battery. Problem is that I can barely get much amperage flow. During charging it's showing a amp rate of .18, not even 1
amp. Is that because the battery is already near fully charged state? Do I need more power from the panel? Perhaps boost up the amps allowed while programming? I would love to get at least 2 amps, Any ideas?
Maybe the charge controller is gobbling up most of the available power to run the display and electronics.
11:57 - Maybe that voltage setting tells the MPPT circuitry to "hover" around that value since it is known for each panel what Vmpp is. For example, if I know Vmpp is 40.0V on my panel, there is no point it having the solar charge controller (scc) check 50.0V and also no point in checking 30.0V. Perhaps it is a starting point so the MPPT algorithm can try voltages close to that value. I have one of those sccs here so I will play around with it and see what happens if I purposely set it too low or too high. My guess is it will take the MPPT algorithm longer to find the ideal value since it may "waste time" trying values that are too far away from the actual ideal voltage.
Hi Julian, have you played with the new A6 GSM chip with a white test board?
Hi.
Thanks for the videos.
Would you help me with something?, i have unlimited ammounts of ebikes batteries 36v, i bough the MPT-7210A, hoping it will charge the batteries which it seems thanks to your videos that it will.
The problem i have now is in finding a 36v inverter to 240v ac, i am in the UK.
Thanks in advance.
This unit is ok for charging batteries but not ideal. This is because it is not a multistage charger that can be programmed for different voltages using the same setting. For example, if I want to let it charge a 36V golf cart as high as 43V during the bulk charging phase, then have it back off to 41V for the maintain phase, I don't see a way to do that other than programming both of those settings and then manually changing it after it finishes the 43V stage.
Would this charge a lawn mower battery 52v 4ah if so how.long would it take to charge any idea thanks
great video I hope they come out with a 12v solar charge controller like this one
need your help again, please!
Here in Israel outside is 45 degrees Centigrades and I am a little warried. Please look at the pictures and give me an advise and tell me if I should be warried and what I should do.
The charger shows that the two batteries are more than 30 volts as you see in the voltmeter and I measured the two together and each one. And the other device says the each battery is full and has the red light of alternator lit but this electric car has no alternator. The green light that shows that the battery is good lights only sometimes. Is this normal? Please help me.
Thank You!
Best regards,
Emmanuel
A combined Buck-Boost converter in a solar charge controler would give you more variablity in the output voltage but on the cost of less overall efficiency! A buck converter can be build very effiecient (up to 98% efficiendy or even more) whereas a buck-boost will be most probably below 85%. This makes a big difference in the whole system and i would always tend to go to more panels in series to get higher voltages to use a buck converter instead of a boost or buck-/boost converter. Even a pure boost converter will normally stay behind the efficiency of a pure buck converter.
I’m not sure why you’d set the battery capacity amp hours... it’s a neat idea, but w/o the device measuring the current draw from the battery, how would it ever know to run AH backwards?
One thing you don't seem to have mentioned is that the solar panel peak voltage must be lower than the fully charged battery voltage. What ever panel/battery combination used. Because if you have a higher voltage panel even if the controller turns off the current will pass through the double diode. So it has to be used in the voltage boost mode.
I am also surprised Julian that you don't have a decent bench PSU considering all the videos you do.
I'm trying to stay true to my "electronics on the cheap" tag line. A lot can be done without needing expensive test gear.
Zoony I thought if there are diodes that prevents especially reverse flow of current to the solar panel. By double diode doesn't that mean stopping current forward flow to the battery? Plus this is a controller and it itself is the starting or stoppage of any flow of current backwards or forwards, right?
What about using this with normal panel setup (36 cell, 19v) and 12v battery system in where batteries are charged in series of two (24v or more..) and output is taken by parallel connections onto those batts (12v)?
gelisob i have tried to figure out such a system but can't figure how to do it without blocking diodes. Unfortunately that results in around 3v drop (2 diodes) which I consider unacceptable.
Massive Thanks for all 3 vids about MPT 7210A but is a real MPPT controller not an UVLO (under-voltage lock-out)?
HI! Good review, By the way - where did You bought that LTC3780 based charge controller?
Alice1101983
Hello, Why I can't get more charge power than 150W on the mpt-7210a regulator? In full sun, I connect 4x230W solar panels in parallel mpp = 29V Open circuit 40V. The rechargeable batteries are 48V 40Ah. The parameters set in the controller are 55V charging voltage and 10A charging current and mppt set to 29V. The regulator shows the voltage on the PV during charging 35V and the battery charging current 3A and the voltage on the battery 50V. The regulator should draw PV voltage to 29V and give a charging current of 10A which would give 500W.
Its puzzle. Can we safely use this for 18650 batteries? I hope it doesn't do trickle charge.
Thanks for showing the components!
What is max wattage it can transfer from panels to battery?
Ill want to use this with 2x300w panels for start for my barn. And charge ups 24v 2kw in capacity.
Edit: forget to mention,it should be 350w constant load.
That thing looks to be a right pain in the arse to set up! I admire your perseverance, Jules! Please though, fix that bend flange xD Crush it flat in a vice or something. Hold a block of wood over it and hammer it flat ("Where's my 'ammer?")
I can't wait to see this eclectic car :D! Solar Freakin' Julian Roadster :D
Brilliant as usual I would love if one day you could test a votronic mppt Duo Digital it’s very good but you’re the best at explaining these so well there are some blogs but they are all German
Please please 👉🏿votronic 👈🏿please send this man one to show to the English language
Cheers 👍🏿
I should have watched the videos before I bought one of these :)
I thought great, a small mppt charge controller to replace the PWM fake i've been using on a 190W panel and 24V system. Never mind.
I guess the company had a particular application in mind that needed quantity. There can't be many uses for a boost controller. It would be nice if they made a buck version.
I experimented with a small 5A mppt bare pcb buck module but only on a 20W panel. A 10-12A version of the 5A module would be quite handy.
My guess is that the voltage set is for you to manually enter the Vmp of the solar panel... suggesting that it's not true MPPT.
This is a good controller for the money but if they spent £20 more on it they could make it great. Im confused at what the solar panel voltage ajustment does exactly? Im pretty sure it uses P&O method to track, which is what you would expect.
The microprocessor outputs a variable duty cycle 1.95KHz PWM on two digital pins, one goes through a 3 stage RC filter and then into an op-amp. The other digital output goes through a 2 stage RC filter and then through an op amp follower. These two signals manipulate the voltage on the boost controller IC (UCC3803) FB and CS pins to get the controller to behaves how it wants.
Problem is these RC filters introduce huge signal propergation delay (60ms for the 3 stage). So the micros new 'instruction set' takes an electronic age to reach the UCC3803 and before the controller can adjust the duty cycle to react to a quick irradiance shift the controller crashes and goes into a soft start cycle. -_-
In layman terms - The controller trips over its own feet when there is a sharp irradiance change due to its slow nervous system.
Hi i am trying to setup small DIY solar project. I have 12 W!/40V solar panel. I want to charge 12 V battery. How can I set up economic charge controller? Most charge controllers are low voltage rating and PWD where we lose lot of energy in DC step down. What is your suggestion? Thanks
Some MPPT charge controllers will do this :)
I found on mine, that the down arrow triggers a current calibration when off to ensure accuracy on the amp readout.