IoT RedBoard ESP32 won't power up from LIPO battery

I recently bought a 1000 mah battery to power my ESP32 Redboard. When I plug it in, the board does not power up. When I plug the USB in and run the gauge sketch, it shows the voltage and capacity as OK. Is there something else I need to do to use it?

If you’ve applied power, it’s powered.

When you say the board “does not power up”, what is it doing or not doing that you expect it to do?

I checked the voltage with a multimeter and it was 3.9V. That’s below the 4.1 that the gauge sketch read so I plugged it in to to 5 v barrel jack for a few hours and it did not change.

Since it is an external battery. I expect the board to power up (LED’s light up, run loaded sketch) once battery is plugged into the JST port on the board without power from USB or barrel jack.

Did you get the battery from sparkfun? If not, the polarity could be wrong.

No, I bought the battery from Amazon. I changed my mind about it. I about broke my fingernails taking the JST plug out of the socket. I’ll stick with my 18650 battery holders.

Thanks