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Views: 0 Author: Site Editor Publish Time: 2026-06-25 Origin: Site
As the Internet of Things (IoT), smart metering, wireless sensors, and remote monitoring technologies continue to expand, the demand for long-lasting and reliable power solutions has grown significantly. Many modern devices are expected to operate unattended for 5, 10, or even 20 years while maintaining stable performance and periodic wireless communication.
Among the various battery technologies available, ER batteries (Lithium Thionyl Chloride Batteries, Li-SOCl₂) are widely recognized for their exceptionally high energy density and ultra-low self-discharge rate. However, while ER batteries excel at providing low continuous current over long periods, they are not ideally suited for applications requiring frequent high-current pulses.
To overcome this limitation, engineers often combine ER batteries with supercapacitors, creating a hybrid power solution that leverages the strengths of both technologies.
But why is this combination becoming increasingly popular, and what advantages does it offer?
ER batteries, also known as lithium thionyl chloride batteries, are primary lithium batteries designed for long-term, low-power applications.
Their key characteristics include:
Nominal voltage of 3.6V
Extremely high energy density
Very low self-discharge rate
Long storage life
Wide operating temperature range
Common ER battery models include:
ER14250 (1/2AA)
ER14505 (AA)
ER26500 (C)
ER34615 (D)
These batteries are frequently used in:
Smart water meters
Gas meters
Electricity meters
Asset tracking devices
Industrial sensors
IoT communication modules
Under normal conditions, ER batteries can provide power for more than ten years.
A supercapacitor, sometimes called an ultracapacitor, is an energy storage device that bridges the gap between conventional capacitors and rechargeable batteries.
Unlike batteries, supercapacitors store energy electrostatically rather than through chemical reactions.
Their main advantages include:
Extremely fast charging and discharging
Very high pulse current capability
Long cycle life
Excellent low-temperature performance
High power density
However, supercapacitors have relatively low energy density and cannot provide long-term power independently.
This is why they are often used alongside ER batteries rather than replacing them.
Many modern IoT devices spend most of their life in low-power sleep mode.
For example, a smart water meter may consume only a few microamps while monitoring usage.
However, when the device needs to:
Send wireless data
Connect to a network
Activate a transmitter
Trigger an alarm
Current demand may suddenly rise from microamps to hundreds of milliamps or even several amperes.
Examples include:
NB-IoT communication
LoRaWAN transmission
GSM communication
GPS positioning
Remote telemetry
These brief but intense current demands can exceed the pulse capability of a standalone ER battery.
The primary advantage of combining ER batteries with supercapacitors is enhanced pulse current performance.
During normal operation:
The ER battery supplies low continuous current.
The supercapacitor remains charged.
When a high-current pulse occurs:
The supercapacitor delivers the majority of the required current.
The ER battery experiences minimal stress.
This arrangement allows devices to support demanding communication functions without compromising battery life.
As a result, engineers can use ER batteries in applications that would otherwise exceed their pulse current limitations.
High-current pulses can accelerate battery aging.
When an ER battery is repeatedly subjected to large current spikes:
Internal resistance increases more rapidly.
Voltage drops become more severe.
Capacity degradation accelerates.
By allowing the supercapacitor to handle pulse loads, the ER battery operates under more stable conditions.
Benefits include:
Reduced battery stress
Slower aging
Improved efficiency
Longer service life
This is particularly important for devices designed to operate for more than a decade without maintenance.
Every battery experiences some degree of voltage sag when delivering current.
The voltage drop can be described by:
Voltage Drop = Current × Internal Resistance
Because ER batteries have relatively high internal resistance compared with high-drain lithium-ion batteries, large current pulses can cause noticeable voltage drops.
Excessive voltage sag may result in:
Device resets
Communication failures
Data loss
System instability
Supercapacitors possess extremely low internal resistance and can deliver large currents with minimal voltage drop.
As a result, the overall system voltage remains more stable during pulse events.
Cold temperatures can significantly affect battery performance.
At low temperatures:
Battery internal resistance increases.
Chemical reactions slow down.
Pulse current capability decreases.
Many outdoor IoT devices operate in harsh environments where temperatures may fall below freezing.
Supercapacitors generally perform better during short-duration high-current events in cold conditions.
When paired with ER batteries, they help maintain communication reliability and system stability even in challenging environments.
Modern wireless communication modules often require substantial current during transmission.
Typical peak current requirements include:
Communication Technology | Peak Current |
|---|---|
LoRaWAN | 50–150mA |
NB-IoT | 200–500mA |
LTE-M | 300–700mA |
GSM/GPRS | Up to 2A |
Without adequate pulse support, communication modules may fail to transmit data successfully.
The ER battery and supercapacitor combination provides a stable power source that can reliably support these peak loads.
This significantly improves communication success rates and overall device reliability.
Without a supercapacitor, engineers often choose larger ER batteries to ensure sufficient pulse current capability.
Larger batteries increase:
Device size
Weight
Cost
By adding a supercapacitor, designers can often use a smaller ER battery while still meeting pulse current requirements.
Benefits include:
More compact device design
Lower overall cost
Improved portability
Greater design flexibility
This advantage is particularly valuable in compact IoT products.
One of the most attractive features of ER batteries is their low self-discharge rate, often less than 1% per year.
When combined with a properly selected supercapacitor, the system can maintain long-term operational stability.
Such hybrid power solutions can often support:
10-year service life
15-year service life
Even 20-year service life in some applications
This makes them ideal for infrastructure deployments where battery replacement is difficult or expensive.
This hybrid power solution is widely used in:
Water meters
Gas meters
Electricity meters
Wireless sensors
Data loggers
Environmental monitoring systems
Logistics tracking
Container monitoring
Fleet management
Street lighting controllers
Parking sensors
Waste management systems
Alarm systems
Remote surveillance equipment
Emergency monitoring devices
In these applications, long life and reliable wireless communication are essential.
As IoT networks continue to expand, devices are expected to:
Operate longer
Communicate more frequently
Function in harsher environments
The combination of ER batteries and supercapacitors is expected to remain a key power solution for these requirements.
Future developments may include:
Higher-capacity supercapacitors
Lower-leakage capacitor designs
Smarter power management circuits
Improved hybrid energy storage architectures
These innovations will further enhance system performance and operational longevity.
The combination of ER batteries and supercapacitors offers a powerful solution for modern low-power electronic devices. While ER batteries provide exceptional energy density and ultra-long service life, supercapacitors deliver the high pulse currents required for wireless communication and other demanding functions.
Together, they offer numerous advantages, including improved pulse current capability, extended battery life, reduced voltage drop, better low-temperature performance, enhanced communication reliability, and greater design flexibility.
For applications such as smart meters, IoT sensors, asset tracking systems, and industrial monitoring equipment, the ER battery and supercapacitor combination has become one of the most effective and reliable power solutions available today. As connected devices continue to evolve, this hybrid approach will play an increasingly important role in enabling long-lasting, maintenance-free operation.
