Unfortunately there is no clear cut answer to this question. LogTag battery life is affected by many different factors:
- If the logger is permanently used in very cold temperatures (<20°C for example) battery life is reduced as the battery needs to work considerably harder to deliver the required power
- If the logger is permanently used in very hot temperatures (>50°C for example) the battery’s internal self discharge increases as does the average current drawn by the electronics, hence battery life decreases
- If the download rate is high, battery life decreases
- If the alert LED blinks often, more power is used and battery life decreases
- If the logging rate is high, more power is used and the battery life decreases
- If the logger is hibernated between uses, battery life increases, as the power consumption between trips is kept to a minimum.
It should also be noted that not all battery cells have exactly the same characteristics. Although they are manufactured to stringent quality specifications, some cells have naturally longer life than others due to the processes used in their manufacture.
Each data sheet contains an estimate for typical battery life in normal conditions; this is based on monthly download and 15 minute logging. Clients have reported shorter battery life for applications of frequent downloading (twice a day) with relatively rapid logging (every minute or less), but also well exceeding the specifications, particularly if they are hibernated between uses.