Return-Path: Received: from pop3.olsusa.com ([63.150.212.2] verified) by logan.com (CommuniGate Pro SMTP 3.5.8) with ESMTP id 1154834 for rob@logan.com; Thu, 04 Apr 2002 07:48:28 -0500 Received: from falcon.prod.itd.earthlink.net ([207.217.120.74]) by pop3.olsusa.com (Post.Office MTA v3.5.3 release 223 ID# 0-71866U8000L800S0V35) with ESMTP id com for ; Thu, 4 Apr 2002 03:25:57 -0500 Received: from sdn-ap-001watacop1408.dialsprint.net ([63.187.197.138] helo=f3g6s4) by falcon.prod.itd.earthlink.net with smtp (Exim 3.33 #1) id 16t2ch-0003sO-00 for lancair.list@olsusa.com; Thu, 04 Apr 2002 00:29:35 -0800 Message-ID: <000b01c1dbb3$3d350b80$8ac5bb3f@f3g6s4> Reply-To: "Dan Schaefer" Reply-To: lancair.list@olsusa.com From: "Dan Schaefer" To: "Lancair list" Subject: Re: 10 volt shut-down Date: Thu, 4 Apr 2002 00:32:19 -0800 MIME-Version: 1.0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: 7bit X-Mailing-List: lancair.list@olsusa.com <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> Scott, The formula you are thinking of is good old Ohm's Law which states that E=IxR (E=volts, I=current in amps, R=resistance in ohms). Put in context of your discussion, you multiply the current draw (I) of the starter by any resistance (R) between the battery and the starter (that's out and back) to find the total voltage drop in the path i.e., from the battery, thru the master contactor, the starter relay, various connections plus the cable resistance to the starter and the resistance of the return path to find the voltage drop (V). If one assumes even as much as 0.1 ohm total resistance and the starter draws 100 amps, you'll lose 10 volts in the wiring alone! Suffice it to say that the starter circuit must be a very low resistance since only 0.02 ohms at 100 amps will bring the voltage applied to the starter down to about 10 volts. Since the battery has an internal resistance, your nice hot 14 volt RG will probably only be putting out 12 volts at that load and the path resistance will shave off the other 2 volts. When it comes to starter circuit resistance, low is definitely better! Dan Schaefer >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> LML website: http://members.olsusa.com/mkaye/maillist.html LML Builders' Bookstore: http://www.buildersbooks.com/lancair Please remember that purchases from the Builders' Bookstore assist with the management of the LML. Please send your photos and drawings to marvkaye@olsusa.com. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>