If you have set up your Roost Smart Battery correctly and are using a digital multi-meter to read the battery's voltage, you may note that it reads 8.2 volts even when brand new. The reason for this is that the patented Roost Smart Battery is different from a standard battery. A traditional 9 volt battery's output will decline over its life to 7.5 volts, at which level your alarm will start chirping to warn you of a low battery. The Roost Smart Battery functions more like a power regulator; it will provide a near constant voltage to your alarm until the very end of its life.
All smoke alarms will work with a battery that has a output of 8.2 volts. If you install a new Roost battery that has been set up correctly into your alarm and your alarm chirps as if it has a low battery, it is for a different reason than the power level of the battery. Please see our Help Center article: Are there any alarms that do not work with the Roost Smart Battery?
If your battery is new and its voltage reads less than 8 volts, please see our Help Center article: My Roost battery reads 0 volts!
If you have any additional questions, please contact customer support.