Many people may have or have bought vernier calipers for £10 ish, excellent value, measure in inches and cm and fractions of an inch, unfortunately magnetic, but for the price excellent value. But, they run through the little button cells batteries quite quickly. The reason is they are on all the time, it's just the display that the on/off button operates, so after use remove the battery. PS. Under a little tab usually at the top above where the batter is found is a connector for a digital output which is a handy hack.
My battery lasts very well and have yet to change it since swapping to silver oxide batteries last year. On mine, the current taken when "OFF" is sub 1-microamp on mine i.e. I can't read it.
I did manage to flatten the battery very quickly on a short set of calipers - I was keeping them in a mug on the desk, along with the usual pens etc and I'd foolishly dropped them back in, still open (but off) - it turned out that the on/off is so easy to press that it was toggling every time I reached for something else in the mug (as well as switching units and thinking zero was in a very odd place!). But keeping an eye on things like that - and avoiding putting them on the table upside down, for the same reason - and the current battery seems to be holding up nicely.
I've got some bottom range Mitutoyo's (which seem to use the same electronics as some of the cheaper brands) and not had a problem. Before that I had some Sealey ones (low end UK brand) which didn't have auto power off...those went flat a few times through me putting them down and forgetting Oh and small tip for people experimenting with things like magnet secured interchangeable carriages...keep your digital callipers away from the magnets, that's how I killed my Sealey ones, they ended up getting packed near one of those magnetic pickup tools in my toolbox
Yes I found this out some time ago with a cheap set I bought off ebay. So I a set locally and haven't had any problems. Also just back from Shenzhen where I bought another set (amongst other goodies) so will see how they go.
