Batteries in an electric watch winder typically last between 3 to 6 months, depending on factors such as the weight of the watch, the rotation cycles selected, and the type of batteries used (alkaline or lithium D-cell) . Some high-capacity lithium-ion batteries may provide a lasting charge from 10 to 100 hours of continuous operation, but generally, for alkaline or lithium D-cell batteries, 3-6 months is the common lifespan before replacement is needed .

Certain watch winders offer low-power notifications to alert users when battery replacement is necessary, and signs of low battery include the winder stopping, the watch no longer keeping accurate time, or unusual rattling sounds from the winder .

In some cases, premium watch winders like those from TaiHua powered by D batteries have been reported to last several months, with some users experiencing battery life extending up to 8 months or more under intermittent use . However, continuous operation on AA batteries may only last from two weeks to a month .

In summary, for typical battery-powered watch winders, expect battery life to range from a few weeks (if running continuously on AA batteries) up to 3-6 months for alkaline or lithium D-cell batteries under normal usage conditions. High-quality models and intermittent use can extend this further, but regular battery replacement every 3-6 months is recommended for optimal performance.