If you experience one of the following, this could be due to a low battery:

• Downloading data isn't possible
• Software freezes during download
• Strange light patterns. E.g. light does not always come back on.
• Difference in temperature/humidity
• If your Logger is relatively new and you still have the same problem, please send us a diagnostics file. 

What affects the battery life of my Logger?

The estimated battery life on the products page and/or the battery specifications table is based on
15-minute logging interval and monthly data download. Battery life of your logger can differ and is affected by many different factors: 

• Permanent use in very cold temperatures (<-20°C for example) may reduce battery life as the battery needs to work considerably harder to deliver the required power.
• Permanent use in very hot temperatures (>50°C for example) may reduce battery life as the battery’s internal self-discharge increases, as does the average current drawn by the electronics.
• A more frequent download rate and/or a shorter logging interval than specified in the product brochure may affect battery life.
• If the alert LED blinks often, more power is used and battery life decreases.
• Hibernating the Logger between uses will minimize power consumption between trips and maximize battery life. This applies to all Loggers apart from the low-temperature Loggers – SRIL and TRIL.
   

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.

Our battery specifications table contains an estimate for typical battery life (average between 2-3 years) 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). On the other hand loggers have been reported to well exceed the specifications, particularly if they are hibernated between uses.

Remember, our Loggers have a 12 month warranty, so if you have a Logger that is relatively new, but still encounter a battery problem, please send us a diagnostics file.

How can I tell if a LogTag battery is low?

LogTag Analyzer displays the current battery condition of a logger during configuration and also after download.

TRIX-8, TREX-8 & HAXO-8 models contain a simple battery diagnostic circuit, which measures the battery voltage and returns ‘OK’ or ‘LOW’. This is just a status and it is not possible to calculate a %remaining battery life from this data. The point at which the battery reports ‘LOW’ is typically when around 15%-20% capacity is left, which in normal operating conditions is equivalent to around 3-4 months of typical use.

SRIC-4, TRIL & SRIL designs contain a battery life monitoring system. These products not only return the actual battery voltage to the software, but also keep track of their activities so LogTag Analyzer can calculate a ‘% battery life remaining’ value, once the battery capacity falls below 50% of its original value.

TRID and TRED models report high or low based on battery voltage. If the low battery indicator is not showing, the Logger is OK for the next trip / recording period. Once the low battery indicator is showing, the battery should be replaced before the next use.

An incorrect low battery indication can occur if the logger is still very cold during communication, as it is more difficult for the battery to deliver power at low temperatures due to the chemistry used. The battery condition is therefore more representative when reported at room temperature, around 20°C.

What happens if I keep using a Logger which shows a low battery?

If a Logger reports a battery as ‘OK’ during configuration, there is typically enough operational life left to complete a trip before being completely exhausted. Sometimes such a trip can even last several months, as the battery threshold that triggers a ‘LOW’ reading has enough safety margin built in to allow for the battery to go ‘low’ during the trip. If, however, a product shows ‘LOW’ when being configured or downloaded, it should not be used again, but discarded in accordance with local regulations.

If you continue to use the Logger despite a low battery warning, there may not be enough power left to correctly record and store data, or to communicate with a PC. Often this leads to data corruption and sometimes complete data loss. For SRIC-4, TRIL & SRIL models the software can calculate the estimated % remaining at the conclusion of a configured logging trip and block configurations that can result in a battery being empty before the trip end.