Good day to all. We've been approached by one of our clients to come up with a=20 wireless data logging and reporting system. This is going to be used=20 to monitor Lithium battery packs for failure. These battery packs are comprised of Lithium primary cells used in=20 groups of 6 (3 wide x 2 end-for-end) cells per array, 4 or 5 arrays=20 per system. The cells are size "CC" and look like two "C" cells=20 stacked end for end. They are mounted on the outside of the system=20 enclosure but will have another skin added to the system before it is shipp= ed. The issue is that the customer will very occasionally have one or=20 more cells fail while they system is on its' storage cart. They want=20 us to supply a wireless monitoring system that will alert them of a=20 temperature rise and then continue to provide live (real-time)=20 temperature data should the cell (or cells) proceed to the "vent with=20 flame" stage and then through the cool-down phase. Maximum temperature that has been recorded on a cell undergoing=20 failure is about 175C - the temperature sensors should be able to=20 withstand that temperature and then continue to report as the=20 temperature falls back towards ambient. The monitoring system will=20 be mounted away from those cells and it is unlikely that it will be=20 exposed to temperatures much above ambient. This system needs to have wireless connectivity because the storage=20 carts are mobile. They are happy with us using their internal WiFi=20 network but other wireless options are also acceptable. I'm not sure=20 what kind of battery life they want the monitoring system to have but=20 I think that we have the freedom to add as much battery as necessary. Because they evacuate the facility when one of these cells fails, the=20 wireless signal must be accessible from outside their building's=20 perimeter. The facility's WiFi network works well in that regard. The main issue for the customer is that the temperature monitoring=20 system must be easily installed and removed from the device without=20 being damaged. We are working on ideas for that right now. I'd like the monitoring system to have at least 10 inputs but more=20 would be nice. The most ideal would be to have a temperature sensor=20 for each cell (30 cells max) but that may not be feasible. I'm=20 planning on using thermistors for many reasons - some models of=20 thermistor are good for up to 300C and they are relatively=20 inexpensive to replace should a system actually have a cell failure=20 that proceeds to the 'vent with flame' stage. Sample rates: once per minute is fine while the temperature is below=20 some threshold. Sample rate should increase to once per second or so=20 after the temperature has increased above that threshold. I would=20 also very much like to have some form of logic output that signals=20 when that threshold has been reached. I'm hoping that someone can suggest a suitable system that is=20 available for purchase. Quantity is going to be only 6 systems or so=20 which makes this a project that I don't want to develop internally. We need both ends of the equation: the wireless monitoring system=20 itself as well as the software that makes the data available=20 externally. An ideal system would use a web browser to access and=20 display the temperature in real time. Suggestions gratefully accepted. dwayne --=20 Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax www.trinity-electronics.com Custom Electronics Design and Manufacturing --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .