All LogTag loggers and indicators are powered by batteries, or have backup batteries if powered via USB.
Depending on the model, the battery is either fixed, or can be replaced by the user.
For a list of LogTag products and each of their battery specifications, refer to the battery specifications table here.
Please only use batteries from a reputable brand.
If you operate a logger with a flat battery, you risk that the logger suffers memory corruption as a result, which may cause a loss of data.