Li-SOCl₂ batteries for industrial monitoring terminals
A sealed terminal lives or dies by the balance between its standing current and its periodic bursts, so the duty cycle comes before the model.
A monitoring terminal is usually sealed and installed where a service visit costs far more than the cell inside it. Its load is a low standing current, a measurement burst on a schedule and, where the terminal also reports, a transmission pulse on top of that.
Because the enclosure is closed, the duty cycle has to be understood before the cell is chosen. Send the measurements the terminal takes and how often, the working current, the peak current and duration of each measurement or transmission, the cut-off voltage of the electronics, the temperature at the installation point and any sealing or mounting requirement for the pack.
What decides the battery
Measurement schedule
How often the terminal wakes and what it measures at each wake
Working current
The draw while awake, including sensing, logging and any display
Burst and transmission current
The peak drawn by each measurement or radio burst
Pulse duration and frequency
How long each burst lasts and how often it repeats
Cut-off voltage
The level below which the electronics reset or log an error
Operating temperature
Ambient at the installation point across the year
Enclosure, sealing and mounting
Space, ingress protection and how the pack is fixed inside
Which configuration fits
Terminals that report rarely, at moderate current and with a wide voltage window can run from a single ER cell. Where a burst pulls the voltage below the electronics' cut-off level, an ER + pulse capacitor configuration is evaluated on the measured pulse. Where the capacity requirement or the enclosure excludes a single cell, a series or parallel pack is built to the available space.