Chapter 8. Maintenance and TroubleshootingModel PM880 Portable Hygrometer User’s Manual 1518.10 Recharging the BatteriesThe PM880 is powered by a rechargeable NiMH battery pack. The batteriesmust be charged 4-5 hours until the amber LED on the charger goes out, toreceive the maximum charge. When fully charged, the batteries provide 16to 24 hours of continuous operation, depending on the probe type andPM880 usage. An internal battery gauge indicates the remaining power inthe batteries.Before you recharge the battery pack you must make sure the charger isproperly configured. Use the instructions below to properly charge thebattery pack.8.10.1 Removing the Battery Pack1. Make sure you are in a general-purpose location where you can safelycharge the pack.WARNING! THE BATTERY PACK CAN BE INSTALLED AND REMOVED INHAZARDOUS AREAS. HOWEVER, IT MUST BE CHARGED INGENERAL-PURPOSE AREAS ONLY.2. Remove the four thumb screws on the back panel of the PM880 thatsecure the pack.3. Lift the pack out of the unit.
