Thread sensorTag Voltage and battery life

Projects Thread Sensor Tag
#1
  • deep sleep power consumption

deep_sleep_current
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Period Average Current
deep sleep 3.19 uA
sensors acquisition 54 uA
wakeup cycle 1.7 sec including RF 125 uA

see also Low power performance section :

  • battery life

stress test with a full report (2 segmented rf packets) every 3 seconds, battery drop from 3.2 V to 3.01 V so ~ 0.2 V in 49 days

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  • minimum battery voltage
    crash happened at 2.65 V might be due to another issue
#2

test with PPK2

  • dropping voltage down to 1.690 V still keeps the Tag running
  • cut happens at around 1.650 V
  • re increasing the voltage gradually from 1.650 V up to 3.3 V does not bring the Tag back running but stays in an inconsistent state
  • switch off and on at 3.3 V bring it back running

Switch on at Voltage

  • 2.0 OK
  • 1.9 OK
  • 1.8 OK
  • 1.7 OK
  • 1.65 Fail

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logging

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#3

Thanks @wassfila for that test. I found this paper about “Coin-cells-and-peak-current-draw”
and based on that added a 100uF cap to one of my Sensortags

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Lets see how this will turn out. I have 2 Tags which died within the past few weeks because both are kind of running for the same time now (few month) so the battery is getting low on juice. I can now directly compare if the one has this issue more often then the other.

1 Like
#4

I think we need to observe from inside rather. Easiest is with led status to see if the loops keeps running, if it’s an os crash or an i2c bus crash.
If it’s an os crash we need serial debug to figure out the crash adress