Return-Path: Received: from relay03.roc.ny.frontiernet.net ([66.133.182.166] verified) by logan.com (CommuniGate Pro SMTP 4.3c2) with ESMTP id 750060 for flyrotary@lancaironline.net; Sat, 19 Feb 2005 00:59:54 -0500 Received-SPF: pass receiver=logan.com; client-ip=66.133.182.166; envelope-from=canarder@frontiernet.net Received: from filter07.roc.ny.frontiernet.net (filter07.roc.ny.frontiernet.net [66.133.183.74]) by relay03.roc.ny.frontiernet.net (Postfix) with ESMTP id 815A935807D for ; Sat, 19 Feb 2005 05:59:09 +0000 (UTC) Received: from relay03.roc.ny.frontiernet.net ([66.133.182.166]) by filter07.roc.ny.frontiernet.net (filter07.roc.ny.frontiernet.net [66.133.183.74]) (amavisd-new, port 10024) with LMTP id 12379-07-38 for ; Sat, 19 Feb 2005 05:59:09 +0000 (UTC) Received: from [127.0.0.1] (67-137-68-72.dsl2.cok.tn.frontiernet.net [67.137.68.72]) by relay03.roc.ny.frontiernet.net (Postfix) with ESMTP id D35EA358076 for ; Sat, 19 Feb 2005 05:59:08 +0000 (UTC) Message-ID: <4216D5A1.9080805@frontiernet.net> Date: Fri, 18 Feb 2005 23:58:57 -0600 From: Jim Sower User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7) Gecko/20040514 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: 2nd battery Re: Amps required to run engine & amp- hours available References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Antivirus: avast! (VPS 0507-4, 02/18/2005), Outbound message X-Antivirus-Status: Clean X-Virus-Scanned: by amavisd-new-20040701 (2.0) at filter07.roc.ny.frontiernet.net <... If the 2nd alt. is big enough to carry essential loads, it can be lighter ...> The problem is that for it to be a true /backup/ and not merely /redundant/, you would have to figure out a way to drive it - preferably at the other end of the engine. Two alternators driven by the same belt (or belts anywhere near each other) doesn't solve much. Particularly in light of the fact that belt failures probably outnumber electrical failures, and when a belt fails you don't know /what/ it's going to cascade into. Where you gonna put the 2nd alt? ... Jim S. Charlie England wrote: > jbker@juno.com wrote: > >> Now THAT'S encouraging ... but I think I'll tote a spare anyway .. >> what's 12#? ... Jim S. >> --------------------------------- >> >> Jim, I'm torn between 2nd battery. Tracy had one for a while, but no >> longer and don't believe ED had one. Flying over the lower 48 without >> a 2nd battery once I'm past 40 hours does not bother me, but think I >> will have the option to run the 2nd one anytime I'm over water >> flights (a long time from now!) or doing another flight to Alaska. >> >> Bernie >> >> > > For those that don't follow the Matronics Aeroelectic list, the > moderator now recommends 2 alternators and only one battery, replaced > at each annual inspection. His logic is that modern batteries like the > Hawker, etc. are so reliable that you aren't any more likely to lose a > battery *in flight* than a wing while alternators aren't quite that > good. If the 2nd alt. is big enough to carry essential loads, it can > be lighter than even the 12 lb battery & your endurance isn't battery > limited. > > A lot tougher to install, though. > > Charlie > > > > >>> Homepage: http://www.flyrotary.com/ >>> Archive: http://lancaironline.net/lists/flyrotary/List.html >> > >