Compaq today voluntarily recalled about 55,000 battery packs used in its Armada E500 and V300 notebook computers, saying the batteries can short-circuit and potentially cause fires inside the machines. The move by Compaq came just two weeks after rival Dell issued a similar recall notice for about 27,000 batteries that were sold with models of its Latitude and Inspiron notebook PCs that were introduced in June. However Compaq said the two recalls aren't related beyond the similar nature of the problems afflicting the batteries used by the two PC vendors. A company spokesman said the battery packs being recalled by Compaq were made by Sony, whereas Dell said previously its batteries were produced by Sanyo. In both cases, the affected batteries can short-circuit, causing them to overheat, release smoke and potentially catch on fire. Compaq said it recently discovered the defect in a single battery pack that was manufactured between June 2 and July 10. The pack overheated and released some smoke, damaging the PC it was installed in, the company added. Although just that one problematic battery pack has been found so far, Compaq said it and Sony "consider this defect a potential risk due to the high levels of heat and possibility of fire." The recall is being made "to ensure the safety of Compaq's customers," it said. Users affected by the recall are eligible to receive two free replacement packs for each one they have now. Compaq urged users to immediately discontinue use of the recalled batteries, which were distributed worldwide as standard components of the Armada notebooks and as separate options or replacement spares. The serial numbers for the defective battery packs are as follows: TCGK 00001- 10500, TCGK 20001- 21800, TCGK 40001- 83100 and TCHK 40001- 44700. Compaq also has set up a Web site with more detailed information about the recall. Compaq and Dell aren't the only PC makers to be hit by a recall because of faulty components this year. In May, IBM announced a recall of about 220,000 AC adapters used with the company's ThinkPad notebooks and other mobile devices.