Battery life calculation for NRF52 and NRF51(Beacon kit)

RE: Battery life calculation for NRF52 and NRF51(Beacon kit)

Somesh Burkule — Fri, 14 May 2021 06:22:04 GMT

How did you calculated total average current 4.2 uA?

Thanks,
Somesh Burkule

RE: Battery life calculation for NRF52 and NRF51(Beacon kit)

Sigurd — Wed, 14 Aug 2019 11:19:03 GMT

Hi zeal, nRF52811 is not added yet, but it should be close to identical to the nRF52810 when it comes to power consumption.

RE: Battery life calculation for NRF52 and NRF51(Beacon kit)

zeal — Wed, 14 Aug 2019 10:32:10 GMT

Hi,

nRF52811 is not provided in the choices of online power profiler, may I know where can I set and check the power consumption of it?

RE: Battery life calculation for NRF52 and NRF51(Beacon kit)

Sigurd — Fri, 03 Aug 2018 14:45:10 GMT

I would recommend that you measure the current consumption on your custom device. For this I would recommend the Nordic PPK.

RE: Battery life calculation for NRF52 and NRF51(Beacon kit)

Madhav Aggarwal — Mon, 30 Jul 2018 12:17:15 GMT

Hello, is there any way to calculate the CR2032's life practically without waiting for actual 4.18 years as we are also using NRF52 as beacon in our product and want to assure our customers that it will last atleast the theoretical time?

RE: Battery life calculation for NRF52 and NRF51(Beacon kit)

Sigurd — Mon, 11 Jun 2018 08:45:11 GMT

Hi Nakul Nair,

Let's say you are using around 1.9 µA in sleep(RTC timer running). And with the online profiler, we get around 77µA average during the 3 second advertising with 15 byte payload and intveral set to 150ms. This gives us around 5.5 µA average for the 63 second cycle. Using the forumula in the originally answer in this post, this gives us around 3.2 years battery life, that is including the 0.7 factor accounting for external factors which can affect battery life.

RE: Battery life calculation for NRF52 and NRF51(Beacon kit)

Nakul Nair — Fri, 08 Jun 2018 10:48:02 GMT

Hi Sigurd,

My advertising interval is set for 150 msecs and advertise for 3 secs using a timer and when the timer expires I stop advertising using sd_ble_gap_adv_stop function, I then go in idle state for 1 min using another timer and the above cycle repeats.

I have successfully achieved this, my only query here is what will be my battery life, I am using CR2032 coin cell.

RE: Battery life calculation for NRF52 and NRF51(Beacon kit)

Sigurd — Mon, 04 Jun 2018 12:11:32 GMT

Hi Nakul93,

The BLE specification does not allow the advertising interval to be larger than 10.24 s.

From the BLUETOOTH SPECIFICATION Version 4.2 [Vol 6, Part B]:

The advInterval shall be an integer multiple of 0.625 ms in the range of 20 ms
to 10.24 s. If the advertising event type is either a scannable undirected event
type or a non-connectable undirected event type, the advInterval shall not be
less than 100 ms. If the advertising event type is a connectable undirected
event type or connectable directed event type used in a low duty cycle mode,
the advInterval can be 20 ms or greater.

RE: Battery life calculation for NRF52 and NRF51(Beacon kit)

Nakul Nair — Mon, 04 Jun 2018 11:26:02 GMT

I want to broadcast every 1 min so how to calculate battery life for that..the max value in the online power profiler is 10240 ms

RE: Battery life calculation for NRF52 and NRF51(Beacon kit)

Sigurd — Mon, 24 Apr 2017 13:55:59 GMT

Yes, the default TX-power in the BLE examples in the SDK is 0 dBm.

RE: Battery life calculation for NRF52 and NRF51(Beacon kit)

Usman Rashid — Mon, 24 Apr 2017 13:43:25 GMT

The default TX power of the beacon is also 0 dBm ????

RE: Battery life calculation for NRF52 and NRF51(Beacon kit)

Sigurd — Mon, 24 Apr 2017 13:39:29 GMT

Q1: So if I am not wrong both TX power of the NRF52 and beacon kit can be change by the user easily?

A1: Yes, that is correct. You can use the function sd_ble_gap_tx_power_set to set the TX-power.

Q2: 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?

A2: The default TX-power is 0 dBm. If you want to advertise or connect to other devices using a different TX-power use the function sd_ble_gap_tx_power_set() after you enable the SoftDevice.

RE: Battery life calculation for NRF52 and NRF51(Beacon kit)

Usman Rashid — Mon, 24 Apr 2017 13:24:29 GMT

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?

RE: Battery life calculation for NRF52 and NRF51(Beacon kit)

Sigurd — Mon, 24 Apr 2017 13:12:08 GMT

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.

RE: Battery life calculation for NRF52 and NRF51(Beacon kit)

Usman Rashid — Mon, 24 Apr 2017 12:58:13 GMT

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

RE: Battery life calculation for NRF52 and NRF51(Beacon kit)

Usman Rashid — Mon, 24 Apr 2017 07:58:02 GMT

Thank you for the answer

RE: Battery life calculation for NRF52 and NRF51(Beacon kit)

Sigurd — Mon, 24 Apr 2017 07:54:59 GMT

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.

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