Power consumption in Ampere Hour for nRF52840-DK

[JasonGeo]

Hi,

I am trying to measure power consumption on a nrf52840-DK dev board running custom firmware.

I am using PPK-2 and nRF Connect Power Profiler app v3.1.2 for the power measurement.

During operation, I am seeing 832uA on the average window and 14.1mA on the max window (Tx pwr set to 8 dBm) over a 10 seconds "span". I am not really a hardware engineer hence I struggle to debunk the numbers.

Does 832uA means the board is drawing on average 832uA of current per second?

What would this value equate to in terms of ampere hour? Reason for asking is I have a battery rated for 120Ah. I want to calculate how long I can run the DK board on this battery. Can you provide a formula for calculation?

There is a big difference between average and peak current, is that normal? Should I use the average or peak current for proper power consumption?

Thank you.

[Ivan Herrera]

Hi Jason!

It might be worth skimming through a basic physics course as this will clear up a lot. 1 Ampere Hour is the equivalent of the amount of charge that 1 Amp of constant current would have drawn for 1 hour straight. The formula is: current x time = ampere hours. So if you want to solve for time, you divide ampere hours by your current.

It's normal for the average and peak current to differ a lot. Use the average current you expect your application to use.