Random spikes in short term battery status checks

Hello everyone,

I'm trying to check the battery charge every minute for MetaMotionR. The method I'm using is I subscribe to the battery signal and wait 1 second to get a reading then unsubscribe and wait a minute and so forth for 8 hours approximately. I noticed there are some random spikes in the charge and voltage. Please refer to https://imgur.com/ypf0rg5. I want to know what is the source of these spikes. I should also mention that the tag wasn't charging. Thank you


  • edited December 2020

    It's most likely a spike when Bluetooth or a sensor is turned on. For a micro second, something might demand a few milliamps of current to start running in so creating a spike. This is 100% normal.

  • Thanks, @Laura for the comment. Is this because of the way the tag is monitoring the battery?. I took a look at the schematics of the MetaMotionR tag and got the idea that the tag is monitoring the battery by feeding a signal from the battery using a voltage divider into an analog pin and then quantize the analog signal to get an estimation of the battery. Are my assumptions true?. Thanks again.

  • Yes you are correct. But dips will still happen when the bluetooth radio or sensors turn on.

Sign In or Register to comment.