Teardown of cheap calipers: https://www.youtube.com/watch?v=fKSSY1gzCEs https://www.youtube.com/watch?v=fKSSY1gzCEs Power consumption analysis: http://www.dave

Teardown of cheap calipers: https://www.youtube.com/watch?v=fKSSY1gzCEs https://www.youtube.com/watch?v=fKSSY1gzCEs Power consumption analysis: http://www.davehylands.com/Machinist/Caliper-Batteries/ http://www.davehylands.com/Machinist/Caliper-Batteries/ > The Mitutoyo caliper draws about 1/4 the power of the chinese caliper when on, and about 1/8 the power when off. SR44 batteries should last longer than LR44. For infrequently used cheap calipers, one workaround for short battery life is to remove the battery between uses, https://www.garagejournal.com/forum/threads/electronic-calipers-battery-drain.410825/#post-7620411 https://www.garagejournal.com/forum/threads/electronic-calip... > cheap calipers never actually turn off.. because the encoder they use is not an "absolute" encoder. You push the caliper all the way to the closed position, push "zero", and then the circuitry simply counts the number of pulses that goes by and figures out how far the caliper moved. If the caliper fully turned off, it would lose its position and you'd have to re-zero it every time you turned it on. > Mitutoyo Digimatics have what they call an "absolute encoder". The sensor doesn't just count the number of pulses. They've put a special reference pattern on their encoder such that the caliper's circuitry can figure out where it is at any given time. With a Mitutoyo caliper, you can turn it off, take the battery out, slide it to a new position, put the battery back in, turn it on, and it will know exactly where it is. This "absolute encoder" allows the caliper to fully shut down when not in use, greatly increasing battery life. Hacking a switch onto cheap calipers, https://www.instructables.com/Cheap-Caliper-Battery-Life-Hack/ https://www.instructables.com/Cheap-Caliper-Battery-Life-Hac... & https://www.youtube.com/watch?v=GcoUdIjZozY https://www.youtube.com/watch?v=GcoUdIjZozY & http://www.surfacezero.com/g503/data/500/Digital_calipers_added_on_off_switch.png http://www.surfacezero.com/g503/data/500/Digital_calipers_ad...