from Hacker News

Understanding battery performance of IoT devices

by tyhoff on 7/27/23, 2:19 PM with 37 comments

• by sokoloff on 7/27/23, 3:31 PM

  One thing that I found counter-intuitive is that building a device that periodically receives data wirelessly is generally more expensive on the battery than a device which periodically transmits.

  Naively, I assumed that it must take more power to transmit than to receive, which is true on an instantaneous basis, but false on an average basis.

  A device that wakes up every so often, transmits, then goes to sleep can use very little average power as compared to a device that must constantly have the receiver powered up to listen.

• by tyhoff on 7/27/23, 5:02 PM

  Author of the post here - would love to hear about your trials and tribulations of building battery powered devices.

• by tetris11 on 7/27/23, 4:40 PM

  ZigBee is a fantastic low energy protocol for building wireless mesh networks

• by swamp40 on 7/27/23, 10:07 PM

  I've always been curious how the Ring video camera can go "Live" 5 seconds after you click a button on a web browser, but still last for months on a small battery.

• by pcdoodle on 7/27/23, 3:56 PM

  One thing I've played with recently is the rk3308. It manages to pull only 0.4W idle running debian. 512mb RAM and OS on SD Card.

  With a 100Wh laptop battery thats 10 days battery life!

• by howard941 on 7/27/23, 7:36 PM

  A sometimes overlooked resource is your MCU vendor. It may have a power monitoring daughterboard w/ supporting software to help you optimize your battery usage against a development board. The last one I used was Nordic's and it was stellar, free (thanks to the FAE), allowing us to ship a BLE device that would run for at least 1 year on two alkaline AA cells.