Li-SOCl₂ batteries for smart metering
Long standing time plus periodic transmission pulses: metering devices need a cell chosen against both halves of the load profile.
A meter spends most of its life drawing very little current and then draws a short pulse when it transmits or closes a relay. Both halves of that profile matter: the standing load decides capacity, and the pulse decides whether the cell alone can hold the voltage the meter needs.
Selection therefore starts from the reading and transmission cycle, not from a model number. Send the working current, the peak current during transmission, the pulse duration and frequency, the meter’s cut-off voltage and the temperature range the installation sees.
What decides the battery
Application and device
Sets the operating environment and the design direction
Working current
The average load the cell carries between transmissions
Peak current
What the meter draws when it transmits or switches a relay
Pulse duration
How long each transmission pulse lasts
Pulse frequency
How often the pulse repeats — determines recovery time
Cut-off voltage
The lowest voltage the meter electronics still operate at
Operating temperature
Installation environment, including outdoor cabinets
Which configuration fits
A single ER cell may be sufficient where the transmission pulse is modest. Where the pulse pulls the terminal voltage below the meter's cut-off level, an ER + pulse capacitor configuration lets the capacitor carry the pulse while the cell supplies average energy. Series or parallel packs are used where the meter needs a voltage or capacity a single cell cannot provide.