Laptops may get more battery life from silver-zinc

Laptop users may soon get longer battery life from their machines, with ZPower Inc. set to plug in its new silver-zinc batteries, which it claimed last significantly longer than traditional lithium-ion batteries.

The batteries will be available in consumer and business laptops from major PC makers starting in August, according to Ross Dueber, the CEO of ZPower, although he declined to name any of the vendors.

Silver-zinc batteries pack more energy than lithium-ion batteries, giving laptops 40% more runtime, according to Dueber. If a laptop runs for two hours with a lithium-ion battery, it should run for closer to three hours with a silver-zinc battery, he said.

The battery's water-based chemistry also makes it nonflammable, compared with lithium-ion, which uses dimethyl carbonate, a flammable liquid. Cells can go off "like firecrackers" in lithium-ion batteries, Dueber said.

The silver-zinc batteries also won't degrade in capacity during the first year, while lithium-ion batteries can lose up to 30% of their capacity over that period, Dueber said. After a year, however, silver-zinc batteries start degrading at a rate similar to lithium-ion batteries.

Silver-zinc is not a new technology, said Vishal Sapru, industry manager of power systems group at consultancy Frost & Sullivan Inc. Early batteries were mainly for one-time use in military and aerospace devices, and ZPower is adding recharge capabilities to those batteries, Sapru said.

The batteries could be good for consumers who want an alternative to lithium-ion batteries, which have received "unfortunate" publicity lately for catching fire, said Jeff Shepard, president of the Darnell Group.

"What we see here is a very strong product that will alleviate those issues. I don't know if it's going to be a silver bullet, but it could be a viable alternative," Shepard said. Because the technology is relatively new, any imperfections might not be known yet, so PC makers will take a wait-and-see approach, he predicted.

Sapru said he thinks the concerns about lithium-ion batteries are overblown. "Think of how many laptops and cell phones we use and carry," he said. Companies such as Valence Technology Inc. and A123 Systems Inc. are researching phosphate material that should further reduce the fire risk.

It also remains to be seen if silver-zinc batteries can compete on price, since lithium-ion is relatively cheap, Sapru said. The silver-zinc batteries contain silver, which can be expensive.

ZPower is starting off with laptops, but it plans batteries for mobile devices such as cell phones in a few years, Dueber said. The company needs to get the technology validated to encourage other vendors to adopt it.

The focus on mobile products comes partly from Intel Capital, which invested in the company in 2004, Dueber said.

Copyright © 2008 IDG Communications, Inc.

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