Yes - it's not going to be very accurate, but it'll give you a rough idea how long you might expect it to last.
@Gordon started
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
Yes - it's not going to be very accurate, but it'll give you a rough idea how long you might expect it to last.