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Mobile OEMs aim to set battery standard

Posted: 11 Sep 2006 ?? ?Print Version ?Bookmark and Share

Keywords:IPC? OEMS? Li-ion batteries? standard? notebook computers?

A group of about nine systems makers will meet this week (Sept. 13) to take the first step toward setting a quality standard for Li-ion batteries.

Under the auspices of the IPC, representatives from Apple, Dell, Hewlett-Packard, IBM Lenovo, Nokia and other OEMs are expected to set the scope and timeline for a specification they would expect battery vendors to follow. The first target could be defining how to test individual lithium ion cells for contamination, the cause blamed for the recall in August of millions of Apple and Dell notebooks.

"Sometimes adversity brings the greatest cooperation," said John Grosso, chairman of the IPC OEM Critical Components Committee who is chairing the meeting. Grosso is also a director of supplier engineering and quality at Dell Inc. "The question of liability in the supply base is getting major visibility, so the level of cooperation among battery suppliers is high," he added.

Unlike past IPC standards that focused on lower level components such as pc board assemblies and fans for a base of relatively small vendors, the battery issue involves some of the largest and most sophisticated manufacturing companies in the world.

While the scope of the group has not yet been set, Grosso wants the group to draft a specification for the so-called delta overcharge current test. The test compares an initial cell with one that has had a full heat stress test. If the difference in the overcharge current level between the new and tested cell is too great, the lot is pulled for further testing.

The delta OCV test aims to identify cells that have too many contaminants in the electrolyte. Such contaminants were believed to be the cause of problems with Sony Corp. batteries used in the Apple and Dell notebooks that were recalled in August.

"Right now this test is handled differently by each vendor. You can spend a day just understanding how a vendor does its delta OCV test," said Grosso.

The IPC committee has preliminary numbers for what acceptable levels of contamination are, but wants to review them with experts before it makes them public.

Grosso added that the group could also set standards for other parts of the cell manufacturing process. Eventually, it might also try to write specs for battery packs and their interfaces, although that could be a more complex job given the diversity of battery designs.

"If you look at all the failure analysis data, the common failure mode for batteries is in the cell," he said.

The presence of Nokia in the group suggests it could take a charter which goes beyond notebooks to span cellphones and other mobile systems using lithium ion batteries. Grosso said he wanted to set a scope that would include the broadest set of products possible.

Although the majority of attendees coming to the first meeting are from the notebook world, Grosso said the door is open to all comers. "Some people are tentative. They wonder what the IPC knows about batteries and want to wait and see what comes out of our first meeting."

The group's last spec was on fans and took just seven months and $20,000 to complete. Although a battery spec would require more expertise, time and money, it holds even greater value for systems makers, given the history of battery recalls.

The group may reference existing standards including the IEEE1725 spec for cellphone batteries and the IEEE1625 spec for battery cell design.

- Rick Merritt
EE Times




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