PSNet,
Two issues have been discussed here.
1) The general case of battery fires. Stored energy devices, are
capable of starting fires in equipment unless proper circuit protection is
provided. Product standards specify the needed protection for battery
powered equipment and need to be observed.
2) Internal battery failures which lead to fires in the battery
which can spread to the equipment. As the power density of batteries is
pushed up this has become an issue. From the discussions that I have heard,
the failures are due to inclusion of conducting particulates within the
battery structure which lead to hot spots then fires; other causes may also
exist. Manufacturing control is the key here but is difficult since the
contamination is in the ppm region already. These fires cannot be
controlled by protective circuitry external to the battery cell.
As with many technological issues this will continue to improve as
the manufacturing process is cleaned up. However, energy density increases
are still desired and will push this in the opposite direction. It appears
that we will be walking this tightrope for some time to come.
Try not to get too locked in on battery technology or design when
looking at the application of batteries in products. Every manufacturer has
their own wizards and 'secret sauce' to make the battery world better; some
will be better than others.
Yes, you high paid engineers and scientists, welcome to the high
tech casino selecting the magic combo of components to make the next big
thing that will wow the world. (note: 'high paid' = ulcer money for making
the technical decisions that support the marketing folks super-wondrous
product idea).
:>) br, Pete
Peter E Perkins, PE
Principal Product Safety Engineer
PO Box 23427
Tigard, ORe 97281-3427
503/452-1201 fone/fax
[email protected]
-
----------------------------------------------------------------
This message is from the IEEE Product Safety Engineering Society emc-pstc
discussion list. To post a message to the list, send your e-mail to
<[email protected]>
All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html
Attachments are not permitted but the IEEE PSES Online Communities site at
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used
formats), large files, etc.
Website: http://www.ieee-pses.org/
Instructions: http://listserv.ieee.org/request/user-guide.html
List rules: http://www.ieee-pses.org/listrules.html
For help, send mail to the list administrators:
Scott Douglas <[email protected]>
Mike Cantwell <[email protected]>
For policy questions, send mail to:
Jim Bacher: <[email protected]>
David Heald: <[email protected]>
