Review on Akozon Protection Lithium Balancing Function by Emili Hudson

Received the board fairly quickly. I haven't used it yet, I decided to look at the balancing circuit. This is a very "budget" design. A precision reference chip (TL431) is used instead of a zener diode. Substituting the resistor values (R1 = 68k; R2 = 101k (two resistors in series, 100k and 1k)) into the formula (see screenshot from TL431 datasheet) you get Vka = 4.31V (remember, Iref for TL431 is in the range of 2 μA). This means that THIS balancer will start conducting the charging current (through the ballast resistor R3) when the battery voltage reaches 4.31V. Before that, all current flows through the battery (without equalization). Okay, let's calculate the transient current (through R3, which is 51 ohms). Assuming we charged the battery by 100mV (4.41V in this case), the transient current in this circuit is 100mV / 51Ω = 2mA. Wow! Brilliant 2mA! And this is for the BMS which is rated at 20A. It will take days (or possibly weeks) for the batteries to even out. That said, this board will likely work as a battery protector, but it definitely won't work as a balancer. Look elsewhere if you need a working balancer.