Ship to United Kingdom , USD
Top Positive Review for %s on Banggood, Shop best %s with lowest price on Banggood. Browse most helpful positive review for %s before you buy., rc toys, fun sports, fashion, popular electronics
Adi 22/09/2022
The board arrives in Romania from CN in about one month. The MPPT regulator with CN3722 is operating well. I recommend it as the cheapest MPPT I have found (about 9 USD); its operation is based on constant input voltage (called MPPT voltage). It can be used as it is, but I preferred to modify its heatsink because it is a risk of electrical contact, the insulation is the heatsink black paint only; I made a 3 mm hole in the ground connection under D1 and put an additional heatsink on the top of PMOS and diodes - connect them with a 3 mm screw (photo 1 and 2) - under the original heatsink I used kapton tape and thermal paste. The schematic of the board can be seen on figure 3 with the pin names taken from the CN3722 datasheet (typical circuit - photo 4). The adjustment can be done directly with the solar panel (SP) - adjust V_MPPT to the point where the LED(s) are blinking without battery connected; in this point you get 1.04V (typical) on MPPT terminal, over R5; you can adjust V_MPPT also based on the SP characteristics, to the maximum power voltage (about 15..20% less than the open-circuit voltage) using an additional source (with the current limited to less than 1A) settled to the desired voltage (adjust to get 1.04V over R5 and/or to the LED blinking point, without battery). With the battery connected you can adjust the end of charge voltage to the point where you get 2.416V (typical) to the FB pin - over R7, OR when the battery reach the end-charge voltage adjust to the point where the LEDs change the color - from blue to red (dimmed) in my case - blue is charging, red is end of charge (in my case - normally one expects red for charging...). I tested the panel with low light on a cloudy day (w/o heatsink) with a 100W 22V solar panel, I get about 20% more power compared with the MPPT of the XMUND XD-PS1 power station. I will test it also on a sunny day (with heatsink now) and I will add a comment.
Comments (2)
  • Adi Inthe schematics there is a small mistake... VCC is connected to S_PMOS point (after M1 - protection to reverse voltage at the panel input).

    Reply 23/09/2022
  • Adi Thereis a small mistake in the schematic (photo 3); VCC pin of CN3722 is connected to S_PMOS point (after M1 that protects the circuit from reverse input voltage).

    Reply 23/09/2022
Satisfaction Survey

Download APP to get an exclusive 10% off coupon