Paul makes an excellent point. Many newbies assume that while keeping their instrument plugged in they are turning it off and stopping battery drain by turning the PU selector switch to off position. However, for Alembics, the battery drain continues unless you unplug it. Of course, if you have side LEDs it makes sense to always check those too. I’ve drained many more LED batteries than preamp ones because I’ve failed to notice they are on when the house lights get turned up.