from:

http://www.cpsc.gov/cpscpub/prerel/prhtml09/09045.html

DiNotte Lighting Lithium-Ion battery with nylon bags are used with DiNotte 5W Li-Ion bicycle lights and DiNotte 3 LED police lights, sold between 2006 and 2007:

A loose wiring connection and improper venting can cause the battery to overheat...