You can change NRF.setTxPower(...) to reduce power usage. Also if you're not scannable (setAdvertising option) then that can save some power too.
NRF.setTxPower(...)
scannable
@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.
You can change
NRF.setTxPower(...)
to reduce power usage. Also if you're notscannable
(setAdvertising option) then that can save some power too.