HTCC-AB01(V2) and getBatteryVoltage() always getting 0.0020

Hello,

I use my HTCC-AB01 (V2) to measure temperature and send it via lora to TTN. Since I’m using a 18650 3.7V 1200mAh battery connected to the battery plug on the device I’m always getting 0.0020 as output if I use the code:

  uint16_t batteryVoltage = getBatteryVoltage();

I expect that the voltage will be change over the time of a few weeks I’m using it.

Any idea what’s wrong?