Hi  >> APOLOGIES - Im not doing it any more <<     !!! Are You  familiar with basic electronics and soldering and understand this device needs to be switched off when NOT IN USE?? !!! No need to be installed on a bass.. You can remove battery and test it outside the bass... if its still ok the led will not lit up(!)    Worrying about dead battery in the middle of a tune on a gig?  - You do not have to any more with this circuit!   It works