Aug 08, 2013

Press Release

Panasonic Develops Industry's First*1 Nickel-Cadmium Battery Operable at Minus 40 Degrees Celsius

Panasonic's new Cadnica rechargeable batteries, which can operate in cold temperatures, can be used as a rechargeable power source in cold weather regions and for cold-storage warehouses.

Osaka, Japan - Panasonic Corporation today announced the development of the industry's first*1 nickel-cadmium battery capable of charging and discharging at temperatures as low as -40°C (-40°F). The new Panasonic Cadnica GT Series batteries are designed to operate at a wide range of temperatures, from extreme cold temperatures of -40°C to temperatures as high as 60°C (140°F). Panasonic will start shipping samples of the new Cadnica batteries in August 2013. Mass-production will begin in the next fiscal year starting April 2014 with a monthly production of one million pieces.

In recent years, in response to demand for infrastructure development and disaster preparation, interest in backup power supplies for applications such as for traffic signals, communication base stations and servers, emergency lighting in cold-storage warehouses, and standalone power supply systems, such as solar-powered street lights and power storage systems, is growing. However, in regions where winter temperatures fall under -20°C (-4°F), such as Hokkaido, the northernmost island of Japan, the northern U.S., Russia, Canada and the Nordic countries, it is difficult to get stable performance from conventional secondary batteries*2 at such low temperatures. A special heater can be added to such systems to maintain the battery temperature, but this also adds to costs and makes the equipment larger.

Panasonic's new Cadnica GT Series batteries present solutions for these challenges. Thanks to the newly-developed electrolyte management technology and high-performance negative electrode, the batteries can charge and discharge in a low-temperature environment of -40°C, substantially exceeding the operating temperature range of conventional nickel-cadmium batteries*3, allowing nickel-cadmium batteries to be used in a wide variety of locations in cold weather regions, and contributing to cost reductions and the simplification of such systems.

The new Cadnica GT Series batteries will come in three sizes: SC, C ad D. Other applications of the new batteries include the use for equipment designed for cold-weather regions such as radio devices, measuring instruments, mountain-climbing equipment and ship lights; and backup power source used outdoors such as disaster lighting systems and emergency lighting for tunnels.

Panasonic has been offering Cadnica nickel-cadmium batteries worldwide for half a century since the company started mass-production in 1964. Cadnica batteries boast outstanding features, such as large-current discharge and high resistance to over-charging/discharging, which make the batteries a suitable power source for applications such as power tools that call for high-rate discharge capabilities and emergency lighting that requires long-term reliability.

Over the years, Panasonic has accumulated technology and know-how in batteries, such as the proprietary positive electrode sintering technology*4 applied to nickel-cadmium batteries as well as automotive nickel-metal-hydride batteries which use nickel in their positive electrodes. Building on such expertise, Panasonic will continue to pursue technological innovation to bring high-quality products.


*1 In consumer-use, compact, sealed rechargeable batteries, as of August 8 2013, according to Panasonic data

*2 Consumer secondary batteries used for storage purposes (lead-acid, lithium-ion, nickel-cadmium and nickel-metal-hydride batteries)

*3 In consumer nickel-cadmium batteries

*4 Technology for producing porous and strong nickel-based plate by sintering nickel powder at high temperature


1. Industry's first nickel-cadmium batteries capable of charging and discharging in minus 40°C low temperature

In general, the chemical reaction of the active material in a battery is slower at lower temperatures, thus resulting in reduced battery performance. Batteries using a water-soluble electrolyte such as a nickel-cadmium battery lose their functionality in a low-temperature environment below -20°C because the electrolyte freezes.

By adopting the newly-developed high-performance negative electrode, Panasonic has succeeded in improving reactivity at lower temperatures. At the same time, the company has succeeded in suppressing the freezing of the electrolyte by using its positive electrode sintering technology and electrolyte management technology. As a result, the company has achieved charging and discharging at a low temperature of -40°C, substantially exceeding the operating temperature (0°C for charging, -20°C for discharging) of the company's conventional nickel-cadmium batteries.

The new Cadnica GT Series batteries can be used for a variety of cold environment applications, such as as a backup power source for traffic, disaster prevention and information communication equipment in cold weather regions, and in guide lighting and emergency lighting in cold-storage warehouses. These batteries do not require temperature-maintaining heaters, thereby enabling simpler and lower-cost system designs and smaller installation space.

Technology enabling operations in a low-temperature environment
Development of high-performance negative electrode

As the reactivity of the active material of the negative electrode of conventional nickel-cadmium batteries is reduced at low temperatures, charging/discharging under 0°C was difficult with the previous products*3. The newly developed high-performance negative electrode improves the low-temperature performance by approximately 50% through the improved reactivity of the finer active material.

Image of high-performance negative electrode plate

Electrolyte management technology
Nickel-cadmium batteries use a water-soluble electrolyte which tends to freeze in a low-temperature environment. By applying its battery technology and know-how refined over many years, the company achieved a specification suitable for operation at -40°C by optimizing the concentration of the electrolyte.

Proprietary positive electrode sintering technology
When a nickel-cadmium battery is overcharged at a low temperature, the positive electrode active material generally swells, and its operational life is shortened. The company achieved a positive electrode structure with improved strength by applying its proprietary sintering technology to suppress the swelling of the active material, thereby achieving a longer operation life at low temperatures.

With strong nickel structure for firmly
maintaining active material

Surface of sintered positive electrode

2. Capable of charging/discharging not only at low temperature but also at room temperature and even at a high temperature of 60°C

The same technology for optimizing operation in a high-temperature environment used in the company's nickel-cadmium batteries has also been adopted in the Cadnica GT Series, so that charging/discharging in a 60°C high-temperature environment is possible without losing the high-temperature performance of the existing Cadnica batteries. The batteries may also be used at room temperature.

Operating temperature range of Cadnica GT Series

3. Maintaining the over-charging/discharging toughness and outstanding discharging performance, unique to Panasonic's nickel-cadmium batteries

The Cadnica GT Series offers improved temperature characteristics while maintaining the outstanding current discharge characteristics and over-charging/discharging performance unique to Panasonic's existing nickel-cadmium batteries. The new batteries also deliver the performance in a power source for backup systems which require an instantaneous and stable voltage, as well as products such as emergency lighting which require a trickle charging to keep fully charged.


Name Cadnica GT Series
Size*5 SC size C size D size
O.D. x Height 22.9 mm x 43.0 mm 26.0 mm x 50.0 mm 33.2 mm x 59.5 mm
Mass Approx. 47g Approx. 73g Approx. 150g
Typical capacity 1,500mAh 2,500mAh 4,000mAh
Voltage 1.2V
temperature range
-40°C to 60°C

*5 F size batteries are also planned to be released

Cadnica GT series

About Panasonic

Panasonic Corporation is a worldwide leader in the development and engineering of electronic technologies and solutions for customers in residential, non-residential, mobility and personal applications. Since its founding in 1918, the company has expanded globally and now operates over 500 consolidated companies worldwide, recording consolidated net sales of 7.30 trillion yen for the year ended March 31, 2013. Committed to pursuing new value through innovation across divisional lines, the company strives to create a better life and a better world for its customers. For more information about Panasonic, please visit the company's website at

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