Specific to the Magneto Speed this is copied from the instructions.
"The MagnetoSpeed display unit uses four AAA batteries. The battery
life is typically over 100 hours with the backlight OFF and over 30 hours
with the backlight ON. When you need to replace the batteries, simply
unscrew the two screws from the back, swap out all"
High Fence, Low Fence, Stuck in the Fence, if I can Tag it and Eat it, it's Hunting!
"Pain is weakness leaving your body"