Basic alarm clock & battery operated clock - This clock is powered by 4 x AA alkaline batteries only (not included), which can keep Constantly Big 1.2'' LED digit time display for more than 12 months.

⏰【Compact Size & large Dial 】The bedside clock measures at 3 x3 x1.5 inch, light weight (3.35 oz), 1 AA battery operated. The large crystal clear dial screen makes it easy for everyone ...

You should know that this alarm clock is not fully battery-operated—two backup AAA batteries are responsible only for keeping time and alarm settings, in case of a power outage. There are two ...

A Chip-Scale Atomic Clock (CSAC) is an essential reference for these systems, providing the necessary precise and stable ...

These were chunky dual-in-line devices containing clock and non-volatile RAM chips, a crystal, and a lithium battery. The battery was good for about a decade, which was fine for most PCs of the ...