Application
Supercapacitors for Smart Metering
RTC hold-up, last-gasp messaging, and pulse support for metering electronics.
Power requirements
Electricity, water, and gas meters need long-term clock retention and, in many designs, short high-current pulses for RF or cellular transmission. Battery-powered meters see pulses of hundreds of milliamps on top of microamp standby loads.
Why supercapacitors fit
A supercapacitor can buffer transmission pulses so the primary battery sees a lower, steadier current, or provide a ‘last-gasp’ message on mains failure in mains-powered meters.
Selection factors
- Leakage current over a 10–20 year life.
- ESR at the transmission pulse current.
- Temperature range, especially for outdoor installations.
- Compatibility with the primary battery chemistry and charge circuit.
Limitations
- Leakage adds to the energy budget of battery-powered meters
- Long design lives require careful derating
Supercapacitor types
Low-profile button cells for RTC and memory hold-up where current is in the microamp range.
Through-hole cylindrical cells for PCB mounting, typically from about 0.5 F to around 100 F.
Two or more cells assembled in series as a single component to reach higher rated voltages.
Sizing a supercapacitor for smart metering?
Send your load profile and we’ll suggest suitable parts.