BOSCH will replace your laser or measuring tool product that has failed when used in conformance with. product instructions and warnings, with a new laser DO NOT mix old and new batteries. Replace all of them at the same time with new batteries of the same brand and type. DO NOT mix battery chemistries. Maybe Bosch can add that little information nugget to their manual so no one screws up there The GPL5 5 Point Laser is design for interior use only. MB) Bosch GPL5 Technical data • GPL5 laser levels pdf manual download and more Remove batteries if the device will not be used for several months. Bosch GPL5 Manual Online: inserting/replacing the battery, Features, Technical Data, Intended Use. Alkaline Batteries Are Recommended For The Tool. Response from Bosch Tools: Did you change the batteries? I can't find the instructions that describe how to lock it for travel. Bosch Laser Level GPL 5 (3601K66212) Parts and Accessories. Model: GPL5 (3601K66212) Add to My Models 24. Battery Cover BSH-1618C01495Power tool manuals and free pdf instructions. Bosch Power Tools GPL3 Laser Level User Manual Always replace all batteries at the same time.