I think you're fighting a losing battle. Different alloys have an influence, but not enough to overcome the fact that copper has roughly twice the conductivity (both electrical and thermal) of aluminum. You'll need twice the cross-sectional area in aluminum as you would need with copper to achieve similar performance. Your 1.75 inch test shows a lack of proportionality, but that's likely due to short straps and how the current flows locally from the bolted joint.
I'm thinking your best bet is to use copper conductors and be very sure all connections are thoroughly greased (Noalox, Vaseline, whatever) to ensure all moisture is excluded from the joint. And I would re-grease them once a year. Chris On Sun, Sep 21, 2014 at 2:54 AM, via EV <[email protected]> wrote: > I thought folks would like to hear the results of some of my testing. > > 1/2 inch smashed copper pipe, 200 Amps for a 2S2P pack of 8 Ahr "P" (for > Power") Headway cells: Things stayed cool. > > 1/2 inch by 0.02 inch braided strap with smashed copper pipe at > connections: 5 F rise in 90 seconds at 200 A > > 1/2 inch by 0.01 inch Al: 200A, 80F to 200F in about 15 seconds! This was > done in the oxidized state. > > 1/2 inch by 0.01 inch Al: 200A, 80F to 200F in about 15 seconds! This was > done with sanding and immediate Noalox. > > 1.75 inch by 0.02 inch Al: 200A, 80F to 160F in about 30 seconds. > > The Al performed way worse than theory predicted, then I think I figured > it out. Al roof flashing from Home Depot is apparently not a very > conductive alloy of Al. I'd guess better Al would perform much closer to Cu. > _______________________________________________ > 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) > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140921/5d7baf7c/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)
