All physical Time Timers require a battery to operate. For best performance, we recommend the use of high-quality, brand name batteries purchased from a reputable retailer. We do not recommend the use of rechargeable batteries as they tend to become depleted far quicker than traditional batteries.
As you use the Time Timer, its battery will be slowly depleted. Under typical use, the battery in the Time Timer should last at least one year. Frequent use of the Time Timer will keep you productive and on task, but will also deplete the battery more quickly. When the Time Timer is not operating (i.e. the colored disk is not showing) the battery will lose very little energy because the motor that drives the disk is not active. It's recommended that you leave the battery inside of your Time Timer so that it's ready to be used at a moment's notice.
From a technical perspective: Like many physical clocks and timers, the Time Timer uses an electronic oscillator that is regulated by a quartz crystal to keep time. The battery sends an electrical current through this small quartz crystal, which creates vibrations. These vibrations drive a motor which moves the Time Timer’s colored disk.
If you're having issues with your timer, such as the disk not moving, we recommend that you swap in a new battery as a first step to see if that solves the problem.