The Photon 2 does not have a fuel gauge chip, however you can determine the voltage of the LiPo battery, if present. The P2 does not include a LiPo battery connector, but if you connect your battery to
VBAT_MEAS, this technique also works with the P2.
float voltage = analogRead(A6) / 819.2;
The constant is from the ADC range (0 - 4095) mapped to the voltage from 0 - 5 VDC (the maximum supported on VBAT_MEAS).
There is a
CHG pin defined on the P2, however it does not work properly.
Show older information about CHG