I second that. Welding is the way to go. The key to successful spot welding in this type of application is the duration of the arc. A properly set-up welder produces a very hot arc very quickly. The idea is that in the millisecond or two that the arc is being generated not much heat-sinking can occur in most materials. also, the tips carry about 1/2 of the heat away. Hence, the small T value allows for a lot of power without much wasted energy - it's a very localized transfer - if set-up properly. That's why panels shouldn't warp, surrounding plastics not melt, etc...I used to build spot welders that mounted 1/8 in dia brass studs onto .012 in thick brass discs. Mil spec allowed for no warpage of the disc. There was about 1 lb. of pull on the studs in the final assembly and the darn things had to function under water years later. once the welders were set up properly, the failure rate was zero. (as a side note, the weld controllers were based on the old C-64, circa 1985)Electrolytic caps (like a number of other components) have been manufactured by having their leads safely welded in place for many years..how often do the leads fall off? Finally, I've been evaluating J batteries in a project, and some manufacturers weld the interconnecting tabs between the inner cells. I have not yet been able to get these welds apart without destroying the cells. Chris -----Original Message----- From: pic microcontroller discussion list [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Dwayne Reid Sent: Wednesday, January 30, 2002 12:05 PM To: PICLIST@MITVMA.MIT.EDU Subject: Re: [EE]:Safely connecting a wire to a terminal-less battery At 07:03 PM 1/30/02 +1100, Roman Black wrote: >Welded tabs cause MUCH more heat and damage to >the battery, and besides the risk of mechanical >failure from vibration (i've fixed a few) they >WILL NOT take the very high currents needed for >electric model vehicles etc. Welded tabs are >very much a mass-produced low-quality low- >performance solution. Sorry to disagree here, but my local supplier (just down the street!) welds up cells with NO discernable heat remaining after the weld is complete. Each weld is actually 2 welds: one from each tip. They do each strap at least twice (4 welds) unless you specify high current usage - then they use wider straps and weld 5 or 6 times. I accidently shorted a pack made of full size C cells: one of the straps eventually melted! But the welds were intact. I'm guessing the short circuit current was several hundred amps. I've used their welder and done my own cells. The whole thing is pretty automated - step on the foot-switch and the welding tips come down at a controlled rate. There are some tiny sparks a short time after the tips hit the strap - then they stop. Let go of the foot switch and the tips come back up. I don't know if I could make a bad weld even if I tried. dwayne Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 18 years of Engineering Innovation (1984 - 2002) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu