Hi All: Heard some interesting stories about laptop batteries going into meltdown....now considering the term lap-top to imply where they are normally used, the consequences could be MOST interesting..... RE tantalums--many years ago, had a two sided board designed for the S-100 bus. Loaded up the power supply components, included 20 or so tantalum bypass caps, plugged in a board, and powered it up. Every cap exploded. Checked polarity on the caps on the next board--all OK. Plugged it it, with the same results. Checked caps on the bench, all OK. Seems the board house had put the component and solder sides on backwards--so of course the edge card connectors were on the wrong side of the boards--and reversed the plus and minus 15 volts supplies going on to the board. Very expensive lesson in PCB layout and properly marking layers. Also realized that 1uF tantalum teardrop caps make marvelous igniters for model rockets. Back before they invented dirt, I had assembled a rather complex system for an associate--about a weeks worth of work. Passed it over the bench for him to test, and went back to another project. About five minutes later, I heard a "Holy Sh...." form the other side of the bench, and a boiling mushroom cloud of smoke appeared. Joker had clipped a six inch piece of heavily insulated wire from a reel, and shorted a 50-amp supply across it, burning off all the insulation. My project was sitting safely at the other end of the bench. The date was April 01. Enjoy. Kelly William K. Borsum, P.E. -- OEM Dataloggers and Instrumentation Systems & San Diego, California, USA