http://www.ieee-pses.org/symposium http://www.emc2004.org/
At the battery pack level, UL 2054 is applicable and also the newly released IEEE standard IEEE 1625-2004 might be worth a look. Regards, Kaz kazimier_gawrzy...@dell.com From: owner-emc-p...@listserv.ieee.org [mailto:owner-emc-p...@listserv.ieee.org] On Behalf Of Doug Massey Sent: Wednesday, June 09, 2004 7:59 AM To: 'ieee pstc list' Subject: RE: Product vs Battery Approvals http://www.ieee-pses.org/symposium http://www.emc2004.org/ Hi Alex & Courtland- I worked on some Li-Ion designs a few years ago - a couple of the things I remember: Most Li-Ion cells have an internal PTC built-in that will provide one overcurrent protection per cell. The exception to this may be the flexible cells (look like ketchup packs). All rechargeable cell chemistries - NiCd, NiMH, and Li-Ion - have a very low internal impedance, which allows them to deliver higher currents than primary cells, like alkaline batteries. I believe an AA-size Li-Ion cell can easily deliver >50A during short circuit, with the internal PTC disabled. Li-Ion packs are more complex than NiCD or NiMH, which typically only have a 'strap' PTC in series. A typical Li-Ion pack will have a control circuit that monitors for overcharging and rapid discharge. So, you have to analyze the circuit to determine what effect single faults will have. You can help the evaluating agency out, and save time and $$ during the evaluation, if you have done an analysis of the circuit beforehand, and know what effect the various potential single faults will have. The agency will only be interested in single faults that could cause a hazard, so if you can present an analysis beforehand, it should greatly reduce the amount of fault testing required. The control circuit itself will prevent any failures during the normal output short circuit, abnormal charging tests, etc. There are many app notes out there by the chip makers who make the control chips, and most of the app notes will have a lot of details on safety of the circuit. One final comment - if I recall correctly, Li-Ion chemistry does not contain any environmentally un-friendly substances, which means they can be disposed of through normal channels, and do not need to be recycled, like NiCD and NiMH chemistries. I think the only precaution regarding disposal is that they should not be incinerated - each pack will need a warning statement to this effect. The UL C of A's for the cells will specify the warning statement to be applied to the pack. UL 1642 and IEC 61960-2 would be the applicable standards. Disclaimer: I'm no battery expert - these are just some of the things I recalled from previous experience. Consult an expert if you need to! Doug Massey, NCE From: owner-emc-p...@listserv.ieee.org [mailto:owner-emc-p...@listserv.ieee.org] On Behalf Of Cortland Richmond Sent: Wednesday, June 09, 2004 12:22 AM To: Alex McNeil; ieee pstc list Subject: Re: Product vs Battery Approvals http://www.ieee-pses.org/symposium http://www.emc2004.org/ Hello, Alex, Lithium batteries contain a hazardous material -- lithium. It does not like water, and will catch fire just about by itself. Packaging becomes an issue. You may discover your existing product's enclosure is unable to safely or legally accept a Lithium battery. (But it might take another, differently assembled one.) There are also restrictions on shipping lithium. The US Federal Aviation Administration requires lithium cells in automatic defibrillators carried on aircraft to be TSO'd. I am surprised they haven't gone after lithium photo batteries. High power lithium batteries are capable of MANY times the discharge rate we are used to. Short circuit and thermal protection is therefore even more an issue than it is for NiMH batteries. Charging is fussy, and the results of a mistake are... warm. Google around a bit; you'll find some "interesting" stuff. However they have a very long self discharge curve, so they are extremely useful in devices that must work when needed, and they hold a lot of energy for their weight. Bear in mind, so does Picrate! One Amateur operator gets up to 750 watts _output_ from a backpack rig he runs off a Lithium battery. Check out the HFPack group on Yahoo groups for that discussion. (The battery cost -- it says there -- $900.) EMC of smart-battery electronics or battery support circuitry may be an issue. ESD and RF immunity most likely will be issues, insofar as they may cause a charging malfunction. This is one chemistry you do NOT want to have one with. Cheers, Cortland This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. IEEE PSES Main Website: http://www.ieee-pses.org/ To post a message send your e-mail to emc-p...@ieee.org Instructions for use of the list server: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. IEEE PSES Main Website: http://www.ieee-pses.org/ To post a message send your e-mail to emc-p...@ieee.org Instructions for use of the list server: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. IEEE PSES Main Website: http://www.ieee-pses.org/ To post a message send your e-mail to emc-p...@ieee.org Instructions for use of the list server: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
