Batteies/Nickel-metal hydride/Sanyo Nickel-metal hydride 051210
Sanyo Develops Next Generation
Nickel-metal hydride Batteries
Sanyo Electric Co.’s new Nickel-metal hydride battery, ‘eneloop,’ can be used like a dry cell battery - immediately after purchase.
Up to this time, Nickel-metal hydride batteries have released stored energy in small amounts; this phenomenon is called ‘self-discharge’. This feature has not allowed customers to use the batteries unless charged after purchase. This is because a traditional Nickel-metal hydride battery can lose most of its charge between the time it was fabricated and the time it was purchased in the retail market.
The new product (eneloop) has great improvements in self-discharge properties. Residual ratio after one year of non useage is 85%, in temperature conditions of 200 C, according to Sanyo. (See Figure 1.)
Sanyo says that this new battery is a result of using its high-performance negative electrode ‘superlattice alloy’ and the make-up of battery material and battery plates. This new technology not only helps with self-discharge but also inhibits Voltage reduction even after a long period of being out of use.
Because the battery can be recycled and some of its materials such as nickel can be reused, it is superior to a dry cell battery which is normally just placed in the trash. In fact, using rechargeable batteries which are recyclable could reduce the 70,000 tons of used dry cell batteries disposed annually in Japan alone. (Data is from Battery Association of Japan.)
The ‘eneloop’ can be recharged 1000 times over and is therefore economically more efficient than dry cell batteries. Superior low-temperature electrical discharge performance is also noted. (See Figure 2.)
The new battery became available on November 14th, 2005. Pricing is $10 per AA two pack. Larger packs of 4 and 8 and a special recharger will be available, also.
Mitsuru Homma, President of Sanyo’s Mobile Energy, has stated that his company supplies 50 percent of the world’s Nickel-metal hydride batteries which are used in PCs, cell phones and digital cameras.