Expected battery performance depends on many factors. Marathon Products, Inc. recommends that all data loggers be calibrated on an annual basis in order to maintain accuracy and meet published specifications, and part of our calibration procedure includes a mandatory battery change of all loggers. As long as the loggers are sent in for calibration on an annual basis, battery life should never be an issue with your logger.
If, however, you decide to let the calibration lapse, or are merely curious as to how long the battery can be expected to last, this chart can be used to determine the normal operating life of a Marathon data logger. As you can see, if the measurement interval is set for 1 minute, the battery can be expected to last a minimum of 1 year regardless of sensor. As a general rule, the longer the measurement interval, the longer the battery life.