In this video we take a look at two of the most common reasons for rapid battery drain in a bass with an LHZ preamp. A 9 volt battery should last 6-8 months of normal use. However, certain wiring issues can cause an active preamp and pickups to always be powered on and reduced battery life to only a few weeks.
While this video specifies the LHZ preamp, the same issues and resolutions apply to almost all active preamps that use the output jack as a power switch.