By Yoshiko Hara EETimes Supply Network (03/02/2007 3:13 PM EST)

TOKYO — Sanyo Electric Co., maker of the laptop batteries being recalled by Lenovo, claimed Friday (March 2) the defects are limited to Lenovo battery packs only.

At the early stage of last summer's massive recall of Sony-made batteries in Dell computers, Sony also claimed the problem was limited. But overheating problems soon prompted recalls by Apple and Lenovo.

The difference in the latest recall is the source of the problem, claimed Sanyo, the largest lithium-ion battery supplier in the world. It cited a U.S. Consumer Product Safety Commission (CPSC) statement on Thursday that the cause was not an internal cell defect as with Sony batteries.

The problem with Sanyo batteries was traced to an optional, large-capacity battery pack for Lenovo notebook PCs. Sanyo claimed an investigation of each incident pinpointed the source of the problem, adding that in all the five overheating cases battery packs were obviously damaged when laptops were dropped.

While a standard battery pack contains six lithium-ion batteries, three in two rows, the defective packs contained nine batteries, three in three rows, and partly protrude from the PC case.

The longer-life battery packs were designed based on Lenovo's specifications for its notebook PCs. "The pack design for other PC vendors' models are different. We believe the trouble won't spread to other PCs," said a Sanyo spokesman.