Button-cell battery suppliers emphasize battery quality upgrades

	Changzhou Yufeng’s CR2032-Henli Max model has 230mAh nominal capacity and 3V nominal voltage.

LiMnO2 models dominate output, with rechargeable, eco-friendly units among the key trends as new chemistries are explored for differentiation.

Button-cell battery suppliers in China are complementing their cost advantage with quality improvements and high-end technologies to increase competitiveness, especially against Japan and South Korea counterparts. A number of makers have started adopting stainless steel strips, which are typical among models from Japan. Products with this feature are exported both as a stand-alone unit and as an accessory to other devices.

Besides churning out the popular CR LiMnO2 type, companies have begun releasing LIR LiCoO2/C and ML LiMnO2 batteries to explore the upscale categories. Both are rechargeable and environment-friendly.

More manufacturers are increasing their output of rechargeable versions. Such units now account for 40 percent of Kwanwa Electronic Co.’s total yield.

To address homogeneity and counter the tightening price competition, enterprises are adding value and offering premium releases. Some provide zinc-air batteries for implants and electronic hearing aids. The products have a high energy density and are eco-friendly.

Makers are banking on sustained demand from consumer electronics and accessories to boost slim margins. There are now more than 50 manufacturers in China, a huge jump from fewer than 10 in 2004.

Enterprises have an average monthly output of about 3 million units. Major players such as Naccon Power Technology Co. Ltd and Changzhou Yufeng Electrical Co. Ltd produce up to 30 million.

Midsize vendors, which generally concentrate on Li-polymer and rechargeable button-cell variants, have a monthly yield of 500,000 to 3 million units.

Suppliers have an export ratio of 20 to 50 percent. This figure could be higher, however, because part of the turnout may be shipped abroad indirectly by makers of finished devices that bundle the batteries in their packages. The main destinations are Europe, the US, the Middle East and Asia.

Guangdong and Zhejiang provinces are the main hubs, followed by Tianjin and the provinces of Jiangsu and Sichuan.

LiMnO2 button-cell batteries make up 80 percent of China’s total output. These “green” products come in slim configurations. PCs, alarm clocks, calculators, digital watches, toys, medical equipment, PDAs, remote controllers, digital cameras and Bluetooth equipment have been driving demand in the last 12 months. At present, CR2016, CR2025 and CR2032 are the best-sellers because of their wide applications.

Disposable models have a nominal and termination voltage of 3 and 2V, and a typical operating current of 0.1 to 0.2mA. They rely on the stable chemical properties of MnO2 as cathode material and the ultrahigh specific energy of lithium metal as anode input. The average volume decreases less than 2 percent per year, which helps extend the service life. Most adopt a semisealed construction.

CR button-cell batteries work in temperatures from -20 to 60 C. They incorporate overheat and short-circuit protection, and have special storage and disposal recommendations.

CR types with a 9.5 to 30mm diameter and a height of 1.2 to 7.7mm are positioned as low-end. These range from $0.074 to $0.44.

Secondary rechargeable LiMnO2 batteries known as ML are less common. Typically quoted from $0.70 to $1.20, these have a nominal voltage of 3V and capacity of 15mAh. The standard charge/discharge current is 0.1mA. The available models include the ML123A, ML621, ML1025 and ML1216.

LIR batteries, which are rechargeable Li-ion varieties, have a higher voltage than disposable ones at 3.6V. Fully charged units can offer up to 4V. The self-discharge rate is within 10 percent per month with no memory effect, but the 45mAh capacity is just a seventh of LiMnO2 disposable versions.

Li-polymer BR or ICS, and alkaline AG are also on offer. The first has a higher working temperature of -30 to 80 C, but is prone to leakage.

LIR models are classified as high-end, and list from $1.80 to $2.50.

The package size is indicated in the standard name. The most-common type and size are CR versions in 2016, 2025, 2032 and 2450.

Most units meet CE, RoHS and UL requirements.

Makers ask for an increase in quotation for small-volume orders. This is in light of recent moves by some countries, especially in Europe, to emphasize security approvals in shipping. These include UN 38.3 testing and material safety data sheets, which add $2,000 and $400 per product model, respectively. Such a request in price adjustment, however, is rare because the output volume is usually big enough to distribute the assessment costs.

Despite the rising popularity of new battery types, Hong Kong suppliers remain confident of stable growth in the button cell segment. The product is still widely used in computers, wristwatches, handheld games, medical devices, GPS and toys. Many makers in fact continue to invest in R&D, extending shelf life, reducing self-discharge and increasing nominal capacity. Several companies are raising capacity, exploring more environment-friendly manufacturing processes and using alternative materials.

One pressing goal is to eliminate mercury. To roll out models that are on a par with Japan standards, a number of enterprises are importing machines from the country.

The selection in the territory covers various types, including LiMnO2, alkaline, Li-ion, LiSOCl2, lithium polycarbon monofluoride and NiMH.

A few manufacturers also provide silver oxide kinds, but the high cost remains inhibitive for most companies.

Button-cell batteries of the LiMnO2 variant come in standard sizes of CR1220, CR1225, CR2016, CR2025, CR2032, CR2430, CR2450, CR2477 and CR3032. Makers also accept users’ specifications.

Products can be welded with any kind of tab, pin or connector.

Hong Kong has more than 30 suppliers, including overseas-funded and joint ventures. Some have the capacity for over 10 million units a month. Despite maintaining headquarters and sales offices in the territory, almost all manufacturing and R&D activities are conducted in Guangdong, Hubei, Zhejiang and other mainland China provinces.

The output is dominated by button cell specialists. These tier 1 companies are industry veterans with at least

15 years of manufacturing experience. Other makers have a more diverse lineup, covering cylindrical and lead acid types. Several enterprises also provide related parts such as battery holders.

Wentronic Asia Pacific Ltd supplies 3V lithium units in CR1220, CR1225, CR1616, CR1620, CR2016, CR2025, CR2032, CR2430 and CR2450 sizes in blister pack or bulk. It also offers LR43, LR44 and LR54 1.5V alkaline button cells with 100, 145 and 75mAh capacity, respectively.

Strongwill Ultra-Power Battery Technology’s models are available in alkaline, LiMnO2 and Ag2O versions. Units belonging to the second category are in CR1220, CR1620, CR2016, CR2025, CR2032, CR2430 and CR2450 sizes.

Button-cell battery manufacturers in Taiwan are expanding into the trading and distribution business to remain afloat. Thinning margins have been contracting the sector, reducing the supplier population to fewer than five. Most of them regard the product as a service line, contributing only 5 percent to the revenue.

The dominance of Japan-made variants is making it more difficult for companies to boost sales. Even though the former is at least three times more expensive than mainland China counterparts, demand for the first remains robust because of the safety features.

This has prompted mainland suppliers to employ distribution agents from Taiwan and Hong Kong.

Nexcell Battery Co. Ltd, which also distributes Japan-made variants, said it sells more of such types than its own brand. It exports to Southeast Asia, including Malaysia, Singapore and the Philippines, with prices lower than Japan’s but more expensive than mainland models.

Some makers occasionally produce a small batch in their mainland factories when stocks run out.