Dell laptop owners face weeks of delay in getting replacement batteries due to huge demand and limited supply, the company has warned.

Yesterday, Dell announced it was recalling an incredible 4.1 million batteries because of a potential fire hazard.

Dell said it will send a replacement to those affected along with postage-paid packaging to return the old one. The company has been "cranking battery production over the last couple of weeks" in preparation for the recall, a spokesperson said, but it may still take weeks for customers to get the new battery - or even longer for certain out-of-production models.

Owners seeking replacements will receive priority if they use a special Dell website set up to handle the recall, but users of many Latitude, Inspiron, Precision, XPS, and mobile workstation models may still be stuck with only AC power for a few weeks.

Replacement batteries are not available in stores, only from the Dell website, so the recall process is likely your fastest option, the company said.

The current recall follows a much smaller one in December of 22,000 batteries. All the cited laptop models from the 2005 recall are once again affected, according to the Consumer Product Safety Commission's recall notices.

With 24.9 million batteries shipped during the current recall time period, according to Dell, this week's recall involves about one out of every six of that figure, or 16.5 percent of the batteries shipped.

Batteries with the same type of cells that were used in the recalled batteries are also in Sony Vaio notebooks, according to David Yang, a Sony spokesman, but there have not been any reports of any overheating with the Sony laptops.

Different batteries that use the same type of cells can still configure them differently and use different safety controls, he says. Other notebook batteries also use the same cells, but Yang could not yet say which ones.

Sony manufactured the affected batteries, which were shipped with Dell laptops and also sold as replacement models between April 2004, and July 2006.

Metal particles that accumulate during the manufacturing process are breaking through the barrier separating the electrode from the diode within a battery cell, according to Yang. When they reach the diode, they can cause overheating.

The metal particles are "one of those unavoidables, no manufacturing process is 100 percent perfect," said Yang. Sony has since changed to process to use a thicker barrier.