This circuit is a Battery balancer / Equalizer for 12V Batteries (24V battery bank)
You can order this PCB from here:
Parts list:
IC LM324
Mosfet IRFZ44n (2pcs)
Diode 1N4007 (2pcs)
LED (2pcs)
Zener diode 11V
Resistor 1M (2pcs)
Resistor 20K (3pcs)
Resistor 51 ohm (2pcs)
Resistor 100K (2pcs)
Resistor 3K (2pcs)
Resistor 2K (2pcs)
Resistor 1.2K (2pcs)
Resistor 10K (2pcs)
Resistor 5 ohm 50W (2pcs)
Metal enclosure
Circuit:
Note: Its better to using resistors with 1% tolerance for voltage dividers & voltage references
Video:
