The first full draft of a new standard for mobile computer batteries has been completed and is circulating for comment among the companies that created it. The standard, IEEE P1625(TM), “Standard for Rechargeable Batteries for Mobile Computers,” takes a systems approach to improve the reliability of the next generation of rechargeable lithium-ion and lithium-ion polymer batteries.
Once all comments are incorporated, it is expected that a revised draft will undergo broader industry review in October. The standard is targeted for completion in the first half of 2004. A copy of the current draft standard will go on sale in mid September at http://shop.ieee.org/store/ .
The IEEE P1625 effort arose because changes in notebook and handheld computers are placing ever greater demands on their batteries. These demands include the need for more power and greater energy density and the ability to withstand more frequent charge-discharge cycles. It also includes the ability to tolerate usage styles that can cause higher operating temperatures and exposure to mechanical shock, vibration and other stresses.
“Other battery standards tend to emphasize the cell or the pack,” says Jeff Layton, IEEE 1625 Working Group Chair. “This will be the first standard that seeks to improve user experience by addressing the entire system from individual cells to the overall device. This approach makes a lot of sense because the interactions between the battery cell, battery pack, and computer require a close look at the operating envelope for all elements alone and in concert.
“IEEE 1625 will be a voluntary standard that specifies minimum guidelines for the design, validation, manufacture and testing of battery cells and packs and the computer. It will address such areas as qualification, manufacturing process control, lithium-ion battery chemistries, packaging and end-user notification.”
In addition, the standard aims to improve battery reliability by accounting for multi-fault scenarios. This involves examining all relevant battery and system design margins in combination to minimize the risks users might face should a battery fail under intended use or reasonably foreseeable misuse
The standard is based on the collective experience of industry leaders involved in mobile computer cells, packs and systems. The IEEE 1625 Working Group currently contains 18 companies: Battery-Biz, Compal, Dell, Dynapack, Fedco Electronics, Hewlett Packard, IBM, Inventec, Motorola, National Semiconductor, Panasonic, Quanta, Samsung, Sanyo, Sony, Solectron, Texas Instruments and Wistron.
IEEE P1625 is sponsored by the Stationary Battery Committee of the IEEE Power Engineering Society. For more information on this working group, see http://grouper.ieee.org/groups/1625/.