2018-12-27, 02:15 PM
That's a good question! I looked it up - one of the production units I've been looking at is solar powered (https://calypsoinstruments.com/shop/prod...emometer-7), and they claim it will operate a very long time with no sunlight after a charge. As for the unit I was looking at on EBay, the manual says they require "10-15VDC at 29mA RMS".
Pretty darned good!
Pretty darned good!