Is this the port for fan control?

[turenabo]

Since the voltage is measured by resistor divider, it will be affected by the temperature drift of the resistor, and the heating effect of those 20Ω resistors is still very obvious. I decided to add a small fan on those rows of 20Ω resistors. I found that there is a port driven by a transistor at the bottom of the circuit board. Is this port the fan control port? In addition, there seems to be no fan control in this version of the firmware. Has anyone added this?

[Rojoalfa]

I have the same question. Did you connect the fan there? Is it working all the time?...

[stawel]

this connector is connected to 5V and (through the small transistor next to it) to GND.
The small transistor will be switched on whenever VT8 is switched on,
see: https://github.com/stawel/cheali-charger/blob/master/docs/imaxB6/imax_b6_hobbyking_eco06_digital_charger.pdf

in short: the connector will be connected to 5V whenever a battery is charged or discharged,
so yes, it can be used for a 5V fan - but with limited (no) control options.