As far as I know the battery voltage has to be higher then the Solar Voltage with this Controller because it's a step up Charger. I have not tried it by myself but I remember that either Julian Ilet or Adam Welch tried it and found out that a 18V Solar panel and 18V Nicd Battery did not work. The he put 2x 18V in Series and it worked fine.
@@osopolarmovies Another user stated the 7210 charge controller has a PWM fallback option in case it does not need to step up. If this is true it would not be as efficient if it really skips the MPPT in the process. Would be interesting to know but on the other hand for small applications there are cheap mpt-step down controller boards up to 5A that are quite cheap and they are working efficient too. Those are CN3722, XL 4015 and BQ 24650 based solar charge controller without case and (most without any display. I just tried recently all three of them with a 60 and 100W panel by charging a 16.8V 4S Lithium pack and measured the Charging power the archive. The BQ 24650 seems to be the most efficient with the other 2 only 2-3% less. I measured all three in quick succession with the same sun and the same quite empty battery. I also compared the three with a "proffesional bouilt mppt charge controller with the same panel and got the same Charging power. So it seems the 3 cheap Controller boards which cost between 4-8 Euro are a quite suitable option for up to 5A. When I tried the 100 W panel they also did quite well (although 100W is almost to high) only the CN3722 based controller was not able to draw down the Panel Voltage to the MPP of 18V but it delivered Current and did not blow up. Regarding the BMS: Always, when in Series with Balancing, when single cell at least under/overvoltage Protection.
@@schubi128 Interesting! I ordered an XL 4015 but it never arrived. Solar cycle 25 is here and it will bring more clouds. So far OK. Charging normally takes around two hours.
@@osopolarmovies the xl 4015 is the cheapest and the easiest to get and works surprisingly well but needs a diode between output and battery or else 💣. already destroy two of them. One because I forgot the diode and the other for some reason I forgot.
i enjoyed your video. but i am hitting a snag: i set the panel voltage to max 32v, which makes no sense to me as to why i need to set this. then i set the output voltage to 28.8v for two 12v agm batteries in series. then i play with the voltage input using a variable power supply, taking the voltage from 9v slowly to 32v and noticed that the charge controller decides to start over charging my battery. there seems to be some relationship between input voltage and output voltage to battery, no matter how its set. in real life i can see slight fluctuations in voltage throughout the day, but mostly the power output will be affected by amperage. if i set the battery voltage for 28.8v, it should stop charging no matter the input voltage, but it doesnt. i now have the input voltage set to 22.57v on my psu, mimicking a solar panel, and max battery voltage set to 14.4 x 2= 28.8v for two 12v agm in series, but the charger is still trying to put power into the batter at 28.86v x .45amps =12.90 watts. seems like once it hit 28.8v it would stop charging also, if you look at the description of this device it says on the amazon listing that it is for 24v -90v batteries. also, there is no listing for maximum open circuit voltage which is strange to me. it seems like this device also has some sort of step up mechanism and from my short experience, it may even be required to have the voltage of the battery higher than the input from the panel. appreciate the video, just thought i'd share my early thoughts on this unit.
There is a step up mechanism. I use 12V so I have not been able to check how the algoritm looks like. However this is the best charger I have tired. I has worked one year now without any problem. Probably I have to change the fan in the future. Good luck!
Using the charger to lower a high input voltage is very wrong and can cause damage because the 7210a can not control anything and does no "work". it just on with the display and lets you see what is happening. You could save power when you just remove the 7210a because it does nothing in this wrong setup.
@@osopolarmovies It doesnt blow up means not that it works good. Try to lower the current and figure out, that it really doesnt "work" in therms of a "function". The regulator is a boost controller, not a buck. If some day your bms fails, the lithium batteries will for sure catch fire, because you have no option to prevent the charger´s output to behave somehow.. for examle you cannot set the output voltage in a save range (or at all under the input voltage). If you replace the charger with a diode, you will see, it will do a better job in therms of energy harvesting. Both are not fused. This setup is terribly wrong and you lead others to a dangerous setup. In your situation, the input power is low, so the risk is relative low. Others which you lead to this wrong way maybe use more solar and fall into a very dangerous situation...
Your claim that you can set the PV voltage at 22V and charge a battery to 12.6V is totally flawed. In your system for some reason at morning times the panel only gives 10v which allowed you to charge a battery to 12.6v. Since your system is so small (three 18650), they got charged up to full during the morning hours. But later when the output voltage of the panel is higher than 12.6v, nothing will happen. For most other people, a 12v panel will output a voltage much higher than 13v at any time, there is no way one can charge a 12v battery with this controller. I was mislead by your video and tried and failed miserably. I do not want others to have similar wrong believe.
This is a stepup Controller, and it doesn't even do mppt. You are operating it in a wrong way adn it actually decreases the power compared to connecting it by a pwm controller by 20%. In your other operational video, the controller doesn't know better as he cannnot convert 18V the panel delivers down to 12V as pulling the 18V max powerpoint panel down below battery voltage, wasing 45% of available power so it can actually step up10V to 12V. But the panel gives most power at 18V. What you need is a nowmal stepdown mppt charge controller which would give you 45% more power with the same panel. Ironically, 90% of all mppt charge controllers available are stepdown, and that is what you need. You bought one of the very few controllers that are not the right one's for what you do. It may work, but you wasted $60 for that controller that does nothing but waste 45% of the system's potential power.
Thanks. Дякую!
As far as I know the battery voltage has to be higher then the Solar Voltage with this Controller because it's a step up Charger. I have not tried it by myself but I remember that either Julian Ilet or Adam Welch tried it and found out that a 18V Solar panel and 18V Nicd Battery did not work. The he put 2x 18V in Series and it worked fine.
All I can say is that it works perfect, czcams.com/video/l2PeYAy-bjg/video.html
I think the Battery Management System is a key component in this project.
@@osopolarmovies Another user stated the 7210 charge controller has a PWM fallback option in case it does not need to step up. If this is true it would not be as efficient if it really skips the MPPT in the process. Would be interesting to know but on the other hand for small applications there are cheap mpt-step down controller boards up to 5A that are quite cheap and they are working efficient too.
Those are CN3722, XL 4015 and BQ 24650 based solar charge controller without case and (most without any display. I just tried recently all three of them with a 60 and 100W panel by charging a 16.8V 4S Lithium pack and measured the Charging power the archive. The BQ 24650 seems to be the most efficient with the other 2 only 2-3% less. I measured all three in quick succession with the same sun and the same quite empty battery. I also compared the three with a "proffesional bouilt mppt charge controller with the same panel and got the same Charging power. So it seems the 3 cheap Controller boards which cost between 4-8 Euro are a quite suitable option for up to 5A.
When I tried the 100 W panel they also did quite well (although 100W is almost to high) only the CN3722 based controller was not able to draw down the Panel Voltage to the MPP of 18V but it delivered Current and did not blow up.
Regarding the BMS: Always, when in Series with Balancing, when single cell at least under/overvoltage Protection.
@@schubi128 Interesting! I ordered an XL 4015 but it never arrived. Solar cycle 25 is here and it will bring more clouds. So far OK. Charging normally takes around two hours.
@@osopolarmovies the xl 4015 is the cheapest and the easiest to get and works surprisingly well but needs a diode between output and battery or else 💣. already destroy two of them. One because I forgot the diode and the other for some reason I forgot.
i enjoyed your video.
but i am hitting a snag:
i set the panel voltage to max 32v, which makes no sense to me as to why i need to set this. then i set the output voltage to 28.8v for two 12v agm batteries in series. then i play with the voltage input using a variable power supply, taking the voltage from 9v slowly to 32v and noticed that the charge controller decides to start over charging my battery.
there seems to be some relationship between input voltage and output voltage to battery, no matter how its set. in real life i can see slight fluctuations in voltage throughout the day, but mostly the power output will be affected by amperage. if i set the battery voltage for 28.8v, it should stop charging no matter the input voltage, but it doesnt.
i now have the input voltage set to 22.57v on my psu, mimicking a solar panel, and max battery voltage set to 14.4 x 2= 28.8v for two 12v agm in series, but the charger is still trying to put power into the batter at 28.86v x .45amps =12.90 watts. seems like once it hit 28.8v it would stop charging
also, if you look at the description of this device it says on the amazon listing that it is for 24v -90v batteries. also, there is no listing for maximum open circuit voltage which is strange to me.
it seems like this device also has some sort of step up mechanism and from my short experience, it may even be required to have the voltage of the battery higher than the input from the panel.
appreciate the video, just thought i'd share my early thoughts on this unit.
There is a step up mechanism. I use 12V so I have not been able to check how the algoritm looks like. However this is the best charger I have tired.
I has worked one year now without any problem. Probably I have to change the fan in the future. Good luck!
Using the charger to lower a high input voltage is very wrong and can cause damage because the 7210a can not control anything and does no "work". it just on with the display and lets you see what is happening. You could save power when you just remove the 7210a because it does nothing in this wrong setup.
I works extremely good in practice för 1,5 years. The only problem is cloudy days. I cannot control the clouds.
@@osopolarmovies It doesnt blow up means not that it works good. Try to lower the current and figure out, that it really doesnt "work" in therms of a "function". The regulator is a boost controller, not a buck. If some day your bms fails, the lithium batteries will for sure catch fire, because you have no option to prevent the charger´s output to behave somehow.. for examle you cannot set the output voltage in a save range (or at all under the input voltage). If you replace the charger with a diode, you will see, it will do a better job in therms of energy harvesting. Both are not fused. This setup is terribly wrong and you lead others to a dangerous setup. In your situation, the input power is low, so the risk is relative low. Others which you lead to this wrong way maybe use more solar and fall into a very dangerous situation...
Your claim that you can set the PV voltage at 22V and charge a battery to 12.6V is totally flawed. In your system for some reason at morning times the panel only gives 10v which allowed you to charge a battery to 12.6v. Since your system is so small (three 18650), they got charged up to full during the morning hours. But later when the output voltage of the panel is higher than 12.6v, nothing will happen. For most other people, a 12v panel will output a voltage much higher than 13v at any time, there is no way one can charge a 12v battery with this controller. I was mislead by your video and tried and failed miserably. I do not want others to have similar wrong believe.
It is stil working perfectly for me since i made the installation. My lamps are on in the morning and I am just happy.
this is absolutely correct! The charger has no effect on what hapens to the batterys in this situation when the panel voltage is over batt voltage.
@@osopolarmovies Sounds like the BMS is saving your batteries when a higher voltage is passed through the charge controller.
This is a stepup Controller, and it doesn't even do mppt. You are operating it in a wrong way adn it actually decreases the power compared to connecting it by a pwm controller by 20%.
In your other operational video, the controller doesn't know better as he cannnot convert 18V the panel delivers down to 12V as pulling the 18V max powerpoint panel down below battery voltage, wasing 45% of available power so it can actually step up10V to 12V.
But the panel gives most power at 18V. What you need is a nowmal stepdown mppt charge controller which would give you 45% more power with the same panel.
Ironically, 90% of all mppt charge controllers available are stepdown, and that is what you need. You bought one of the very few controllers that are not the right one's for what you do.
It may work, but you wasted $60 for that controller that does nothing but waste 45% of the system's potential power.
Thank you! I didn´t waste money I gained a lot of knowledge by practising.