In all electrical connections we use in devices such as wire terminals, buss bars, circuit breakers, circuit breaker buss connections, are cadmium plated copper or aluminum metals. We do not use any contact aids on cadmium plated devices.
There is a shunt tester that can be purchase from electrical supply houses to test the conductance of a connection. In some installations, we are required to record the data of the connections and verify by a QC inspector. Roland ----- Original Message ----- From: Lee Hart<mailto:leeah...@earthlink.net> To: Electric Vehicle Discussion List<mailto:ev@lists.evdl.org> Sent: Monday, January 06, 2014 11:35 AM Subject: Re: [EVDL] Keeping LiFePO4 battery terminals tight every 10k miles Mark Hanson wrote: > ... I found a few other battery terminal bolts not tight after 20k > miles (even with sealing paint on terminal bolts CALB 130). > So it's best to tighten terminal bolts on lithiums every 10k miles it > seems. I used to tighten terminal bolts on old lead GC batteries > every 500 miles but didn't think it was necessary with lithiums but > apparently they need it as well just less often. Soft metals like lead, aluminum, and copper can "cold flow" due to pressure. Temperature cycling and vibration also play a part. Unfortunately, these factors are common in electrical connections. These soft metals are used for their high electrical conductivity. High currents make the temperature extremes worse due to self-heating. Dis-similar metals are another factor. These create corrosion couples, that corrode if the joint isn't absolutely air tight. They expand at different rates with temperature, leading to large pressure changes in the joint. Inexperienced or cheapskate designers seem to have a total disregard for the metals used in their electrical contacts. They ignore 100 years of experience and use whatever metals are handy. My guess is that if (for example) you bolt a copper strip to an aluminum stud with a stainless steel screw, it's hopeless to expect a reliable connection. -- "Obsolete" means nothing more than "the salesmen would prefer you buy something else." -- Dave McGuire -- Lee Hart -- See my Xmas projects at www.sunrise-ev.com/projects.htm<http://www.sunrise-ev.com/projects.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub<http://www.evdl.org/help/index.html#usub> http://lists.evdl.org/listinfo.cgi/ev-evdl.org<http://lists.evdl.org/listinfo.cgi/ev-evdl.org> For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA<http://groups.yahoo.com/group/NEDRA>) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140106/5c0fd2fa/attachment.htm> _______________________________________________ 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)
