I changed D2 to a Schottky Diode. With a fully charged battery, the 3rd battery bar turns on and off. (unstable)
Since I have a Hugen's NanoVNA-H, PCB V3.2, I chose to stick on with firmware NanoVNA-H_20191018.dfu. (latest release)
Fully charged battery voltage reads 4.1V and after D2 (diode voltage drop) I read 3.91V. That's about 0.2V drop as expected.
Also I have not fully understood all hardware differences between Edy555's design and Hugen's design so not sure if Edy555's firmware shall work correctly on my board.
@ QRP RX - thanks for your offer to modify firmware, but that will not allow me to change/update firmware's as newer versions release. Is there any simpler way out?
BR - Nan
