Typically, a fully charged RF16 and RF46 Rechargeable battery should be able to power a module for approximately 10 days under normal conditions (20°- 40°Cm GPM settings of 60 second Live Interval and 1 valve opening sequence per hour.) As the live interval is shortened and with more rapid valve openings (based presumably on a higher gas production rate) the lifespan of the battery will be diminished. Colder temperatures will also diminish life expectancy. Although modules will function properly at lower temperatures (system operating temperature range is 5°- 60°C), RF16 and RF46 Rechargeable batteries will require more frequent recharging under these conditions. The 10 day estimate is based on having charged the RF16 and RF46 Rechargeable batteries for at least 3 hours using the ANKOM RF25 10-Station Battery Charger to a voltage of at least 6.7 volts. This should always be done before commencing a study. Voltage can be tested by plugging the battery into a module and checking voltage on the GPM software screen. Note that Rechargeable batteries will lose charge when not being used. Also charge batteries whenever the voltage drops to less than 6.3 volts. When running the system, remember to check the battery voltage several times daily and change the batter pack when the voltage decreases to less than 6.3V (in the GPM software, a module's voltage cell will be shaded YELLOW under these conditions). Changing the battery pack during the run will not affect test results.