Steve W. wrote:

You can get VERY tiny slide switches from many sources. Then you install
the switch in the spot on top of the caliper with the contact pad. This
way you just switch the battery in/out of circuit. They last longer that
way.

D.C. ratings are really important here.
There are really tiny switches available as you say
but few will tolerate many activations that include
a current spike measuring at multiples of their
D.C. capability.


--Winston