Marcus Reddish wrote: > 5. Washers make a connection worse. TRUE! I saw a guy in Canada do a > series of conductivity tests using lots of different bus bars, washers, no > washers, etc. The BEST connection was a LARGE aluminum bus bar with NO > washer, using noalox and proper torque.
I'm in Canada, but I'm not the guy who did the test you refer to. ;^> Just to be clear, a washer *between* the terminal and busbar/lug will make a connection worse, but a washer on top of the busbar/lug will not. The current flows between the face of the busbar/lug and battery terminal, it does not flow through the bolt/stud holding them in contact, because the path through the fastener is (relatively) much higher resistance. I have seen this firsthand in my battery lab when a technician decided to use all of the fastening hardware provided by the manufacturer of some large AGMs we were testing. The manufacturer had included an extra set of flat washers (thin stainless), so the technician placed one between the lug and the battery terminal, and one under the head of the bolt. When I checked the pack after an hour or so discharging at 75A, the battery terminal was sinking into the top of the battery case. All connections without the extra washer were fine, and after removing the offending washer from the terminal, it stopped overheating. Cheers, Roger. _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
