Testing Solar Charge controllers for 12V Li-ion battery pack. Which is best? 

Model numbers would be useless, people.... they're cheap Chinese products, so the model numbers will be reused even if the internals change. And a lot of the variation will be from unit to unit, even from the same model (even from the same listing, probably).

Exactly the test i was looking for. Thank you from France !

You’re awesome! Love your videos... I’m always so inspired to expand my system. Still afraid to move to li-ion from lead acid, but maybe I will soon!

I LOVE ALL YOUR VIDEOS you teach me alot. and if You do something that even You think is inefficient or not practical use It is still teaching me sooo much, thank you thank you thank you, helps me alot. i have watched a bunch of your stuff now, and even this little test helped me see the difference between some of these charge controllers because i cant really afford huge lithium and expensive mppt. but i do have some other batteries laying around and drone batteries and may invest in a cheap mppt. but i always read reviews because often times people will say something is mppt but in reality it isnt. i love your real life examples. i almost did the power supply invertor in my van a couple years ago but then went and bought one. after watching your video i realized how easy it would have been , and i would have had alot of people using simple items i already own..... no expense instead i went and spent money when i could have used that money towards mppt or something worth investing in.....

thankyou for taking the time to test and post this

I'm also using cheap pwm controllers and have same problem: Shows voltage lower than real. This can be solved adjusting the floating voltage lower also, always monitoring not charge over 12.7. I also have an intelligent li-ion charger and it charges at 12.65. Good video.

This made my day - cheers

Nice and educative presentation. I have the one with black buttons, and can't even go below 13.7v. I will keep searching for the better version. Greetings from Nigeria

Li-Ion Batteries have specification sheets which actually show you (for most good manufacturers at least) how much normal and maximum amperage they can be charged/discharged at. The "cheap" charger would in this case do the job better because it can only distribute 3 amps across all the 3 lanes for cells. A regular 18650 cell for examle should not be charged over 2 C (thats 2000 mA), going with 1000 mA for each cell is the right way to go because it doesn't stress out the cell. Another thing you may want to take into consideration is that for a cell to last longer you dont really want to charge it up to 4.2 (or more) and don't want to fully discharge it down to the cutoff voltage of whatever the manufacturer specified. From experience I know those Led Acid battery chargers distribute more than 5 Amps across the thick cables they normally come with, when putting 3 Li-Ion cells in series you effectively get them up to 12 v, but keep in mind that each cells Amps do not increment as they stay the same, while when putting them in paralel Amps add up, you could put more Amps in but only at 4.2 V, you could charge a 12 v battery pack only when distributing low Amps.

Great video, love the humor..

Well done! Once again a subject I'm very interested in. Please keep up the good work! The only suggestion I might make is you could mention the approximate cost of each controller. If you pay more do you get better quality? None of them had brand names that I could see. Did you try a Victron?

Thank you. Very helpful

Please keep up the good work!

Thank you!!

2:35 That's a good explanation, that amount of deviation is completely fine anyways.

Thank you love it

I just bought one of these to experiment with. Who knows what they will send me. One upcoming project is to make this work with >30V grid tie panels on a 12V battery operating MPPC. I'll try some LI charging modifications too. I have lots of real DIY solar.

Rather than 3 lithium Ion cells, 3.7 V nominal, charge to 4.2, which makes the battery 11.1 volts nominal with a maximum charge voltage of 12.6 volts. May I recommend 4 lithium phosphate cells, 3.2 V nominal per cell, charge to 3.6 V, for a battery that is 12.8 volts nominal, charged to 14.4 volts. 2 LiFePO4 cells is an exact replacement for 3 lead acid cells. So close, that I have successfully paralleled 4 cell lithium Iron Phosphate batteries with 6 cell AGM lead acid batteries. They're such a perfect match, that any of those controllers would work, with no adjustments!

An electronics guy with a sense of humor.

Great video. Others only use it to charge and then disconnect and state result "it works great". Noone else tried to keep it connected what will happen to battery. OK, one more yt channel found out his controller keeps charging and it cooked his battery. Thank you. Now I know I have to test it before hooking up with battery.

A couple of thoughts. I have one of the blue controllers and the manual states that it has a battery equilization mode for all 3 battery types and this isn't user settable unlike the float voltage that you're measuring. You'll damage your pack when the controller goes into equilization mode. The other thought is you're likely just seeing production variation and if you sampled 10 of each controller you would likely have different results. My blue controller is reading 0.2V low - I plan on figuring out where the voltage divider is in the unit and adjust the values to get it spot on. So I wouldn't go by voltage accuracy as the equilization mode is the real reason not to use the blue controllers. The green ones probably do the same thing.

The title should be "testing cheap solar chargers. Which is the best?" would be nice if you could give some specs Model, Amps Great video!

Question: is there a MPBMS in that battery pack ? If there is, shouldn’t it stop the battery’s from over charging? Or have you got the charge going directly to the battery’s as opposed to going through the BMS ?

Thanks for this informative video. i recently bought the one with black buttons and the voltage measurement is off by 0.2V

I have the 20 amp version of the black button one, the instructions I had with it specifically says only suitable for lead acid batteries, the voltage is not the issue, the charging curve is, since they are different between lead acid and lithium ion, lead acid takes a constant voltage charge, lithium ion take a constant current charge till near full charge then constant voltage.

Hello, do you know any drivers that can be used with a 4S battery that charges up to 16.8v?

May i have the type of solar charger controller? where did you buy the solar controller? thank you

Does the charge controller quality applies for all kind of batteries or just for 12 Li-ion batteries?

Needing info on best setting to use these PWM chargers on a bigger 100ah Lifepo4 battery until I can afford a proper MPPT.

i understand , that this controller is not for litium. but if u put a step up/down module with cc/cv and a balancer ,with overcharge and discharge protection board on the li-ion battery's? would that fix the problem?

@vuaeco It'd be great if you could provide the links for the charge controllers that worked.

love it good video

nice effort

Would you test the green fronted one with lithium charging modes? Include low voltage cutoff and reconnection.

I am using mppt makeskyblue 20A connected on 500wp solar panels for my 70AH lithium 18650 3s , and thats work great . I just limmit 12.5v in my setting . when a daylight and battery full 12.5v the charge controller reduce the Amps . , and stop charging , until the volt of battery down / in use.

Can you list the part-number for the one that worked the best.

Sir did you use a bms in that diy li-ion battery pack, also can you give me a link for the charge controller no. 1 the blue one.

Wanted specifications of the first one without digital screen

Hi, interresting video. i'm looking to buy the one you suggest on Amazon but i find only similar ones for Acid battery... Can you put a reference or a model to be able to find it on internet ? Thanks

If your controllers are pwm (pulse with modulation ) it’s normal to have the overvoltage during your test . Just set the voltage you want at the controller (caracteristic of batterie use) and the controller test the batterie and shut down the output of the panel during the cycle of charge . I'm very perplex if this controller don't work like that . Nice day

Am I suppose to use different type of charger for lead, NiCa, Lithium battery? If I just use adapter has higher volt DC. It will charge. Does method damage the battery? Meaning battery has shorter life???

Hi vuaeco, thanks for the thorough review. I'm thinking to power a small Arduino micro-controller (24hrs) from the USB output, and at the same time using the Solar Controller Output (12V) as external power for the micro-controller to control some 12V motor (2hrs a day). I'm wondering whether having the USB plugged in 24hours will completely drain the battery? Thoughts?

I find a lot of people think that they know it all , but know jack poo, I use the cheap controllers on a 12v motorbike li-ion, it works, does the job,

where is the one of the 2 you recommended available please? regards Ian

Hallo, what is the minimun cable diameter from a 180w solar panel to the controller ?

in germany we call these useless blue trash controllers "door stopper" If you set 13V of whatever that thing still pumps 16v into the batteries, these things are dangerous

Very nice👍👍👍

U could put a charge regulator in series to charge the battery better and faster it will increace the amps

Hi, i have the blue one, the discharge stop is set to 10.6 but it stops at 11.5v? Can you help me? Thanks

Does anyone know if I can hook up 2x different output solar panels to my 12v battery, I'm also using 1 of the controllers like in this video, reasoning asking is because 1 panel puts out about 210w and the other about 140w so would this confuse the controller?

Thanks for the nice overview...isn´t there any charger that charges with 16v? That would be perfekt for a 4S system...

The Great Wall of China idea doesn't sound that bad. Praise the sun!

You are right about the wall.

I'm stuck on which rechargeable battery to buy...

I have one of those for a lifepo 4s setup, and it's only charging at 13.1 when the battery is already at 13.3 fault.

Will that controller be okay to charge a 3s 7p 12 volt battery made with 18650s

Does the low voltage disconnect, disconnect the USB ports? I know the green fronted ones don't.

Any RU-vid poster who has even a hint of an accent seems to attract all the nay-sayers. Please ignore them. They usually don't know what they are talking about. You have obviously done your research regarding charge controller needs for Li-ion cells. Issue for charging Li-ion cells is that charge volts must be monitored and controlled for each cell. Do not exceed the rated maximum charge voltage per cell. Most of the cheap Chinese charge control boards are adequate for slow charging at 1A or less. Some will handle higher charge current but those cost more. Schematics and connection instructions for these controllers are available on-line. Never use a Ni-Cad charger to charge Li-ion battery because they do not have the voltage limiting function, as you found in your tests.

Ware did you get that charge controller . I see ones like it but their not

Funny too! ☺👍

I had tow of these 100A blue ones and they were both defective! All the others are just copies of the blue ones! Are there any solar controllers that actually work?

You can adjust the cuttoff voltage in menu

lol well sadid lol great idea for the wall in china any way i use the blue ones they work great never have had no problems with them

I suspect what your seeing is variation in accuracy of resistor values. Likely they are using 5% resistors to make a voltage divider circuit, to reduce the 12v down to a safe voltage level for the microcontroller to be able to read directly. You could likely buy the same product from different batches and get the results your seeing. More important than all that is lithium batteries really need a nanny circuit. Lithium batteries that are overheating can catch fire if discharged or charged to fast. It very possible the battery pack has internal thermal regulation. But some don't, and it's important to be aware of that. Some lithium based chemistry's exist that are safer than lithium, but I suspect Chinese misleading advertising makes to difficult to really know if you are really buying a lifePO4 battery. Just like these Chinese pwm charge controllers advertised as a mppt

Some controller are made for car batterys which full charge over 14v

hi.just watching your solar charge controller for 12volt battery test.i have some 24volt 7s5p batteries I used as bike battery 48volt.thought can use in my camper van .I have 30wattx3 solar panels.hope to power something in the van maybe only the led lights .

It's ok to skip the battery and the controller and just plug the pannels to the inversor? It's ~18v 5a

I use one of the blue ones with the black buttons it charges to 12.7v my 10p 3s emergency power box ,here's an interesting fact they will show charged to 12.7v but actually it's lower it'd around 12.4v unconnect your solar at 12.7v and take a look now at voltage do a test as I did it will show a safe 12.4v or there about

Can I ask you what you think would be the easiest set up to charge my DeWalt lithium ion batteries by solar power . ⚡☀〰〰🔋⚡ ✌ From Upper Michigan 🇺🇸

BTW, if you are looking to get an accurate voltage reading using a cheap harbor freight meter, that might be very unrealistic.

Please I’m making use of 18650 batteries and I also have this type of change control my question is how do I select and know the battery type of 18650

There are newer versions that support lion . I'm using a particular model called wincong sl03

The number 4 charger is only for acid,gel,gm battery not for li,ni..etc.The second problem with your test is time when you make comparation.At 2Pm is more sunny and increase the power for charge. All that controlers is fine if you don't have many expectation from your solar sistem.

no name givwn for best one pls reply

Would that voltage variance even really matter if you use a bms board? Shouldn't that regulate How much the batteries get charged?

I would love to share my small solar project with you, can we connect?

Question... Say u want to batteries in a hybrid vehicle. An extra one in the trunk to run accessories and keep electric system isolated from car. Couldn't one use a solar controller to charge the Xtra marine battery in the trunk?? And instead of solar input... One uses cigarette lighter plug from car? This way... No Factory wiring is being modified... And all accessories run off 2nd battery... What are your thoughts???

I have an other idea for an viedo for you do to . The load out puts and the charge controlers is the same as the solar charge controller voltage is the same as the battery is that not going to work for most people that have 12v iteams . 16 plus voltage to 12v iteams

Hey, a little late ;-) will it have any serious issue if one use a LED battery and not a Li-on? on test nr 3

Just a question: Every lithium ion 12v battery ive had was comprised of cells making up a voltage of 13.2+ charging at 13.8v Why are these smaller portable too batteries different? surely the cells would still add up to a charged voltage of 13.8ish?

I just got a controller like yours in #1 .. the load output jacks dont put out anything, i use the cheap voltmeter u use (by the way... im upset because the ebay seller advertised mine (color is black not blue).. as an MPPT controller but item and box say PWM......... It only sends 12.5 of the 21.8volts from 25watt solar panel, to 2 deep cycle Rv batteries : ( ....... So i know if i use anything it will drain fast even when the solar panel is pushing decent voltage. ... Bottom line, it appears that it will only maintain the sitting unused battery

What's the difference between 3 blue color scc?

How did you wire the baterry

I ran into this problem and it turned out that my meter was not calibrated. I have 3 volt meters. One expansive and 2 cheap. I used a computer grade power supply to check them. The cheap were .4 volts high. The charge controllers are reading .4 volts high but the correct reading is .4 volts low. I recalibrate the cheap meters wth using the computer grade power supply and keep in mind that the controllers read outs are not to be trusted.

I just bought one with the black buttons, I haven't tested it yet, but this video showed me that I need to be more cautious, if I think it's just a easy plug and play item, and reliable? I just need to be more cautious, even though it said a new 2019 solar controller, me thinking it would be ok, Thx I hear from other videos, that I can put some type of beeper that notifies me when it's over a certain voltage, I don't know where to find it though.

I had one of the blew ones it worked fine till i hooked up a trojin supergel battery my controler fryed its self

Hey don't you know about lithium battery protection board??? Buy one and connect it with the battery now battery can't be overcharged and can't be over discharged. And also no matter you give 12 or 15v it gonna chage property. Same thing i always use. Even i use 19v laptop power supply or charger directly with laptop battery through the built-in charge controller and it works always without any problems.

Good review,and i like your humor.. .anywhey you forgot to mension the voltage drop in the cables going to the battery, this will help (...) avoiding an overcharge, in general always measure incoming voltageAT THE BATTERY, you be surprised at the difference your controller display says in charges or what actually is coming IN the battery,in this case probably a good thing

Super funny but serious note on China wall..

I have bought panel 325w .. which controller to choose 20 40 or 100A actually I bought already 100A and not sure if this was right ... pls help thx

The 3 batteries must have their own equilizers. What you gave done i would do myself but not on expensive batteties.

but what is current doing?

Can we add in a small voltage regulator before connecting to the battery?

These can, and should be programmed. I noticed most of these weren't on the same screen as he tested them. Theres float, under, and load settings on one of these.

Lol @ the solar wall

Please, I have a 40ah lifepo4 pack with 5amps 14.6volt rating with inbuilt BMS, can this type of pmw controller charge it with a 150w solar panels without any issue, considering the charging current might be up to 7 or 8amps?

my solar panel is 20w..my solar charger controller is number two in your line-up the blue one..my question is why the voltage coming the solar panel is always 11.8 what is the matter is there any problems in the charger controller?

Best 20A?

i have one to with the black buttons but my controler goes from 12 volt to 15 volt so lower

one question, why did you mix the connection of the wire?