Welcome to EnviroDIY, a community for do-it-yourself environmental science and monitoring. EnviroDIY is part of WikiWatershed, a web toolkit designed to help citizens, conservation practitioners, municipal decision-makers, researchers, educators, and students advance knowledge and stewardship of fresh water. New to EnviroDIY? Start here

Reply To: Case for Lower Threshold Voltage on Mayfly Stations

Home Forums Mayfly Data Logger Case for Lower Threshold Voltage on Mayfly Stations Reply To: Case for Lower Threshold Voltage on Mayfly Stations

#15188
Jim Moore
Participant

Couple of clarifications:

  • The discharge is a fixed load of 22Ω so ohm’s law works!
  • My question is why is the Mayfly station drawing less and less current as it approaches 3.3 Volts?  Yet the 4G modems continue to work and upload the data.
  • I believe that Shannon said that some older sd cards tend to cause current draw during sleep mode.  Maybe this is what is happening.
  • Matt- I am interested in your coulomb counter?  Where can I get one or is it home brew?
  • I have learned that not all Li-ion batteries are equal in terms of stated Ah capacity.  I bought some from Amazon rated at 4.5 AH yet they were less than half the size of the 2.5 Ah batteries I got from Adafruit!  And the JST connector polarity was reversed!

Cheers

-jim