LiPo charging while in sleep mode

Hardware
1

I have configured my application to spend most of its time in sleep mode. This is to conserve air time and battery life. Ironically, what I observe is a continuously decreasing state of charge on my LiPo battery. I assume that this is because the battery only charges when the Electron is “awake”.
I have the Asset Tracker shield connected, with external 12VDC provided to it.
My Electron is also connected to an external 5V supply via USB port.
My code wakes up for about 2 minutes roughly every 20 minutes. My LiPo SoC decreased from 96% to 83% in the space of 3 hours.
My sleep mode statement is:

System.sleep(WKP, FALLING, TIME_PUBLISH_BATTERY_SEC, SLEEP_NETWORK_STANDBY);

Clearly I must be doing something wrong. Can anybody advise me on best practice for extending battery life, keeping the LiPo charged, while also minimizing air time and energy consumed? Does the LiPo battery charge during sleep? Should I use a different sleep mode?

2

I think (but would need to confirm) Stop Mode Sleep - as you are using - does keep the GPIOs the way you had them before sleep, so if you have anything drawing power connected there, your LiPo will be drained faster than you’d expect.
You could use SLEEP_MODE_DEEP (aka Standby Mode Sleep) or power down any external circuitry before going to sleep.

But for your topic title, the battery does get charged during sleep modes too - unless you deactivated charging by code :wink: