Power consumption in Ampere Hour for nRF52840-DK

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.

Parents
  • Hello JasonGeo,

    You can run the experiment for a bit longer time (for example: around one hour or less) to get a bit more accurate value of average current and maximum current. It is not uncommon when these two have difference. For example: there is different in current consumption for idle period and advertising period. 

     ''I want to calculate how long I can run the DK board on this battery. Can you provide a formula for calculation?''

    battery life calculation formula is -

    Battery Life (hours) = capacity (mAh) / Average current (mA)

    There is a few online calculator Battery Life Calculator | DigiKey Electronics to do this. You can calculate on there as well. 

    Thanks.

    Best Regards,

    Kazi Afroza Sultana

Reply
  • Hello JasonGeo,

    You can run the experiment for a bit longer time (for example: around one hour or less) to get a bit more accurate value of average current and maximum current. It is not uncommon when these two have difference. For example: there is different in current consumption for idle period and advertising period. 

     ''I want to calculate how long I can run the DK board on this battery. Can you provide a formula for calculation?''

    battery life calculation formula is -

    Battery Life (hours) = capacity (mAh) / Average current (mA)

    There is a few online calculator Battery Life Calculator | DigiKey Electronics to do this. You can calculate on there as well. 

    Thanks.

    Best Regards,

    Kazi Afroza Sultana

Children
Related