Applied Measurements Limited
B24 Telemetry User Manual
80
Appendix D – Battery Selection
The following section applies to transmitter modules. Some enclosures will determine the battery type and size.
Considerations When Selecting Batteries
Re-chargeable or replacement
This really depends on the application. Some applications where expected battery life with alkaline batteries will
be many years would probably not warrant the use of re-chargeable batteries. Re-chargeable batteries have
implementation issues such as how to connect to the charger, how to seal this connection if required, can the
batteries be re-charged at a convenient point in the operation of the module i.e. between shifts and does the
voltage, when charging, exceed the maximum supply voltage of the transmitter module if so the inline charging
module will need to be fitted.
Required battery life
Driven by the application and mainly dependent on measurement rate and sample time. The operation would
normally require that the transmitter module is used in Low Power Mode to maximise battery life.
Size of
Choosing a battery will be influenced by how much space is available and what battery life is required, generally
the bigger the battery the longer it will last.
Operating temperature range
A battery’s useable capacity is influenced by its operating temperature. Generally, the lower the temperature the
lower their ability to provide charge. Beware of the batteries specified operating range when considering a
particular battery technology.
Self-discharge.
Batteries are chemical devices and have a shelf life which needs to be considered in application where long
battery life is required. Typically an Alkaline has a battery life of 5 years.
Connections to battery
If sourcing battery holders for OEM transmitter modules be aware that some holders with springs only on one
side of the battery can temporarily disconnect a battery when subjected to a shock force. This may have the
unexpected effect of resetting a module. In the case of a B24 module that is connected via Bluetooth then this
connection may be dropped.
Environmental
Other considerations when selecting a connection method to the Batteries is the effect of vibration. A standard
battery holder is a poor choice in applications when the module can be subject to vibration. This is due to the
interruption of supply from the battery to the transmitter module caused when the spring arrangement holding
the battery to the terminal of the holder is defeated.
Corrosion of terminals must also be considered as this will also introduce resistance into the supply connections.
This could be overcome by ensuring the enclosure is sealed.
