Apple is recalling 1.8 million lithium-ion batteries for its iBook and PowerBook notebook laptops, just a week after Dell took a similar step.

The batteries, which were supplied by Sony Energy Devices Corp, could overheat and pose a fire hazard to consumers, says the US Consumer Product Safety Commission (CPSC).

Apple has counted nine reports of overheating, including two instances that caused minor burns from handling the hot computers.

A statement on the CPSC website suggests "consumers should stop using recalled products immediately unless otherwise instructed".

Earlier the CPSC had reviewed batteries for Apple's 15-inch MacBook Pro notebooks but determined they didn't pose any safety threat.

The batteries were used with the following computers: 12-inch iBook G4, 12-inch PowerBook G4 and 15-inch PowerBook G4. No other Apple laptops are involved, including the Intel-based MacBook and MacBook Pro ranges.

Affected consumers are advised to contact Apple or log on to Apple's website to check the battery's serial number and request a replacement battery.

Affected models

The affected batteries were sold worldwide from October 2003 through August 2006 for use with the following notebook computers: 12-inch iBook G4, 12-inch PowerBook G4 and 15-inch PowerBook G4.

12-inch iBook G4: Battery model number: A1061. Serial number range: ZZ338 - ZZ427, 3K429 - 3K611 and 6C519 - 6C552

12-inch PowerBook G4: Battery model number: A1079. Serial number range: ZZ411 - ZZ427 and 3K428 - 3K611

15-inch PowerBook G4: Battery model number: A1078 and A1148. Serial number range: 3K425 - 3K601, 6N530 - 6N551, and 6N601

If the first five digits of the battery’s 12-digit serial number fall within the noted ranges Apple requests that a replacement battery be ordered immediately. To view the model and serial numbers labelled on the bottom of the battery, users must remove the battery from the computer. The battery serial number is printed in black or dark grey lettering beneath a barcode.

Long wait

"We discovered that some Sony batteries in previous models of PowerPC-based iBooks and PowerBooks do not meet Apple's standards for safety and performance," said Teresa Weaver, a spokeswoman for Apple.

The affected batteries were built in Sony plants in Japan, Taiwan and China, then sold by Apple between October 2003 and August 2006, both in new computers and as replacements. They include 1.1 million packs sold in the US and 700,000 sold in other countries.

Apple is telling users to remove the faulty cells immediately, so those customers will have to stay near an AC power outlet to use their computers while they wait four to six weeks for a new battery to arrive.

Apple has not yet decided what type of battery it will send users in return, Weaver said. However, the company will collect the faulty ones for safe disposal.

We didn't start the fire

The move comes shortly after Dell announced it would recall 4.1 million rechargeable batteries for its laptops, the largest recall in the history of the consumer electronics industry.

The defect in Dell's batteries, which Sony also manufactured, happened when tiny metal shards left over from the manufacturing process pierced the battery cell walls, causing a short circuit by touching an anode or cathode. Apple did not describe the cause of its own problem, but it involves the same type of battery.

This new recall could have harsh financial implications for Sony, which pledged to help pay for Dell's recall. However, Apple said the recall will not affect its bottom line.

"We do not anticipate this recall to have a material financial impact on Apple," Weaver said. "Our number-one priority is to recall and replace the affected batteries free of charge."

Apple, like Dell, forecast no material impact of the recall on earnings. Apple shares closed up 0.74% at $67.9, but Sony shares slipped 2.61% to $43.26.