When will particle shut down when powered by lipo

Hardware
1

Hey,
I have an E-Series board, only powered by a lipo.
at what SOC will the board be shut down? IS there even a mechanism to save the battery from getting all the way empty?

Thanks

2

The LiPos sold by Particle have their own protection circuitry built-in and IIRC the shut-off voltage for that is at 3.2V but that’s already below the value the device can reliably run.
Your code should keep an eye on the SoC reading and adjust its mode of operation accordingly (e.g. <20% hold off from cell connections and extend sleep/charge periods, ~0% shut down operation entirely).

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3

Thanks,

whats a good pratice to do so? Say at SOC<20% i go into deep sleep for 60s, check then again for SOC go back to sleep?

4

Just to add to @ScruffR's great comments..... I like to use the LiPo Voltage instead of SOC.
SOC is an approximation from the PMIC, and can be influenced by several circumstances.
The direct Voltage measurement doesn't care if the Fuel Gauge has been sleeping/stopped, etc.
Just try not to take the measurement while the board is performing the cellular connection, as it may result in slightly depressed voltage measurement.

I like to use 3.6V as the starting threshold for a Progressive Sleep Schedule.
If the Voltage continues to drop lower than that, then increasingly aggressive steps are taken for power savings.

You can definitely go lower than 3.6V, but I like it for a starting point for shedding load.
There's just not much remaining in this area of a Li-Po's discharge curve. Things happen rather quickly compared to the higher voltage area of the curve.

60 Seconds seems pretty quick to me. I wouldn't expect any change in the Li-Po condition after 1 minute, no matter what the recharging source is.

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5

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