Snark tuner is a good un.

Derick,seagullplayer,

At just this last Thursday's practice, I finally replaced the battery in my black Snark (the one that lives at church with my workhorse guitar).  I don't use it every day, but it gets used a minimum of 4 times per week.  I only seem to need to change it once every 1.5 years so far.

The type of battery I buy hasn't seemed to matter, but I haven't been timing it really.  The last batch were dollar store batteries.  This one I replaced with a brand name "Maxell" battery.  Don't know where or when I bought those, but they were in my little "guitar stuff" kit case.  lol.