Ron, Although AA cells have similar basic dimensions, their detailed construction, and therefore their overcurrent capabilities, depends on the cell manufacturer. Likewise, the protection device will be as defined by the designer of the battery pack. I would suggest that you ask the questions of the manufacturer of the product that you are in the process of qualifying.
Geoff Lister [email protected] Senior Engineer Motion Media Technology Ltd. Horton Hall, Horton, Bristol, BS37 6QN, UK Voice direct +44 (0) 1454 338561 Voice switchboard +44 (0) 1454 313444 Fax +44 (0) 1454 313678 http://www.motion-media.com -----Original Message----- From: [email protected] [mailto:[email protected]] Sent: 19 September 2000 18:26 To: [email protected] Subject: N-MH Batteries Hi, I am in the process of qualifying a product the uses a nickel metal hydride (N-MH) battery. It is shrink wrapped and appears to be four AA cells in series. the rating is 4.8 volts, 1100 mAh. My standard requires a fault analyses of the charging circuit. As I have had no experience with N-MH batteries I can only guess what the expected outcome will be when overcharged. The faulted charging circuit could be either 6.5 volts at 2 amps, or 9 volts at 1 amp. I have only one sample to test so I can't afford to make a mistake. What will I expect to see? Does the N-MH battery come with a built in vent? If so, does the vent release toxic, flammable, or any other hazard? Is there a chance of explosion? There appears to be a fuse under the shrink wrap. Is it to prevent high current in the event of a short? Our could it be a thermal device to prevent overcharging? Any other hints or advice? Ron Duffy Agilent Technologies Colorado Springs Division. ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: [email protected] Michael Garretson: [email protected] For policy questions, send mail to: Richard Nute: [email protected] ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: [email protected] Michael Garretson: [email protected] For policy questions, send mail to: Richard Nute: [email protected]
