Battery life calculation for NRF52 and NRF51(Beacon kit)

[Usman Rashid]

Hi,

Is there any battery life calculations for NRF52 and NRF51 (Beacon)?

For example: if TX power of NRF52 is 0 dBm and it broadcast every 5 seconds ? Or with any other random settings.

[Sigurd]

Hi,

You can estimate the current consumed by the nRF52 using the nRF52 Online Power Profiler. Based on this and the capacity of your battery you can calculate the battery life as:

Battery Life [hours] = Battery Capacity [mAh] / Device Consumption [mA] * 0.70

where the factor of 0.7 makes allowances for external factors which can affect battery life.

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Using 0 dBm, TX payload 15 bytes, voltage 3 and BLE interval 5000 ms you will get a total average current at 4.2 uA. If you use a CR2032 coin cell battery with a 220 mAh capacity we can calculate the battery life as:

220 mAh / 0.0042 mA * 0.7 = 36666.66 hours =  4.18 years

[Usman Rashid]

Thank you for the answer

[Usman Rashid]

What about beacon kit ( NRF51) is there any online battery life calculator for that as well ?

[Sigurd]

Unfortunately, there is no online power profiler for the nRF51.

But, the nRF52 has generally lower current consumption than the nRF51. For typical advertising intervals, you will likely see that the nRF52 uses about 30 - 50 % less power than the nRF51 depending on your application.

[Usman Rashid]

So if I am not wrong both TX power of the NRF52 and beacon kit can be change by the user easily?

Please also tell me what is the TX power of the NRF52 when is connected to other device, when it is just advertising and when it is in the scanning mode?