@RWB , @ScruffR Good news!
I connected the Electron via the JST connector to a 3 AA battery pack and the unit works well. I then disconnected the battery pack and connected the LiPo battery and the USB cable to my computer and the Electron.
Added the following to lines to see if the Fuel Gauge was harmed by the 6 volts from the 4 AA battery pack yesterday:
FuelGauge fuel;
Serial.println( fuel.getVCell() );
Serial.println( fuel.getSoC() );
Result:
voltage: 3.94
soc: 67.16
Bottom line the Fuel Gage on my Electron is ok!
Like I said earlier in this post I have been running a Photon for three months on 4 AA batteries. Should I pair down the power on the Photon to 3 AA batteries too? I am connected via VIN and GND. It was my understanding from the documentation that the VIN on the Photon could handle 6 volts from the 4 AA batteries but why use the extra battery if not needed. What are your thoughts?