Dell Inc. has agreed to replace 4.1 million notebook computer batteries made by Sony Corp. because they can lead to fires.

Dallas ? Dell Inc.’s record-setting recall of 4.1 million notebook computer batteries raised safety concerns about the power source of countless electronic devices, but experts said the problem appeared to stem from flaws in the production of the laptop batteries, not the underlying technology.

Customers began calling the company and surfing to a special Web site, www.dellbatteryprogram.com, Tuesday to order replacements for the lithium-ion batteries that could cause their Dell machines to overheat. The batteries were supplied to Dell by Japan’s Sony Corp.

The batteries were shipped in notebooks sold between April 1, 2004, and July 18 of this year.

Replacement orders would be filled on a first-come, first-served basis, said Ira William, Dell spokesman. He said he couldn’t estimate how long customers would have to wait for new batteries. The replacements are coming from Sony and a few other manufacturers.

Roger Kay, an analyst with Endpoint Technologies Associates, called the situation “a nightmare for Sony” but said the recall wasn’t likely to scare manufacturers away from using lithium-ion batteries.

“This is a manufacturing problem and not an indictment of lithium-ion technology,” he said.