NRF52810 using CR2032 in freezing temps

Hello Nordic team, 

We have developed a smart tag using the NRF52810. We are looking at using it in asset monitoring application. 

It is powered by 2x cr2032 in parallel. 

My question:

1. Have your customers been able to power the nrf52 via cr2032 coin cell in freezing temperatures (-10 deg C)? Is there a better coin cell for this application. 

2. what would be a good capacitor size to ensure brown outs do not happen, given that BLE adverts take (~10ma for 380 us) x 3, while the CR2032 can only supply a 200ua current. 

The reason I ask is that I've tested 8 tags and they all fail in the freezer in 2 days. When I inspect the cell voltage, its at 1.5v or 1.6v. When I run the tags outside, they last months. I am assuming there was a brownout event, which pulled the mcu into reset which then discharged the cells. 

Kind regards, 

Hari 

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  • Hi Hari,

    We don't know what all our customers do with their products and what temperature range they will be operating in and if we did am am not sure we would share all the info on how many is successful and what they are doing to be successful in X and Y situations/use cases. 


    I've tested 8 tags and they all fail in the freezer in 2 days.

    Are you able to log the voltage during this test? to confirm what is happening. 


    What does the datasheet of the  CR2032 batteries say on operating range?

    Regards,
    Jonathan

  • Hi Jonathan, 

    Thanks for getting back. I am mainly looking for best practices that Nordic Semi can recommend for operation of the NRF52 in low temperatures when powered by a coin cell battery. So perhaps if you can share any insights from your internal testing using coin cell batteries that would be appreciated. 

    I will purchase a NRF power profiler kit try to log the voltage during the test. Does the NRF power profiler support logging over a long duration, such as 48 hours?

    I am using a murata cr2032. Datasheet says it can operate down to -30deg C. At a steady 200ua draw the battery is spec'd to last 900 hours in -10 deg C. 

    Also, could you please recommend a capacitor size for such an application. 

    And, in the event of a brownout, what is the brownout current consumption of the NRF52810. 

    Kind regards, 

    Hari 

Reply
  • Hi Jonathan, 

    Thanks for getting back. I am mainly looking for best practices that Nordic Semi can recommend for operation of the NRF52 in low temperatures when powered by a coin cell battery. So perhaps if you can share any insights from your internal testing using coin cell batteries that would be appreciated. 

    I will purchase a NRF power profiler kit try to log the voltage during the test. Does the NRF power profiler support logging over a long duration, such as 48 hours?

    I am using a murata cr2032. Datasheet says it can operate down to -30deg C. At a steady 200ua draw the battery is spec'd to last 900 hours in -10 deg C. 

    Also, could you please recommend a capacitor size for such an application. 

    And, in the event of a brownout, what is the brownout current consumption of the NRF52810. 

    Kind regards, 

    Hari 

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