X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: Date: Fri, 06 Nov 2009 07:36:31 -0500 Message-ID: X-Original-Return-Path: Received: from elasmtp-mealy.atl.sa.earthlink.net ([209.86.89.69] verified) by logan.com (CommuniGate Pro SMTP 5.3c1) with ESMTP id 3950822 for lml@lancaironline.net; Fri, 06 Nov 2009 07:26:12 -0500 Received-SPF: none receiver=logan.com; client-ip=209.86.89.69; envelope-from=colyncase@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=NiGB8gJoishXwJuRuAgrWl7sr76Z6Ee7uFfeME2Y6Arc9Zol0yoIeA4Tou4/mCQu; h=Received:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE:X-ELNK-Trace:X-Originating-IP; Received: from [216.57.118.33] (helo=ccaselt3) by elasmtp-mealy.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1N6Nsm-0003S1-SJ for lml@lancaironline.net; Fri, 06 Nov 2009 07:25:36 -0500 X-Original-Message-ID: <00ea01ca5edc$3ec69c20$e48c020a@nvidia.com> From: "Colyn Case at earthlink" X-Original-To: "Lancair Mailing List" References: Subject: Re: [LML] L-IVP Battery Cooling X-Original-Date: Fri, 6 Nov 2009 07:25:36 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00E7_01CA5EB2.55A692D0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3598 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3350 X-ELNK-Trace: 63d5d3452847f8b1d6dd28457998182d7e972de0d01da94050f77abb7b0ad1b03332cf1e61c3d0cf350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 216.57.118.33 This is a multi-part message in MIME format. ------=_NextPart_000_00E7_01CA5EB2.55A692D0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Clark, sounds like good stuff! I think Eric is right in general about the battery not being able to = melt the wire but I suggest you look at the battery specs e.g. at = odyssey and see how impressive their short term currents really are. = e.g. you can be over 200 amps for 30 secs going through a starter. If = you size it big enough, Eric is right. If it's not big enough you = could definitely melt it down. If you get a dead short across the = wires then it will be way higher current for way less time. e.g. I = think a odyssey pc680 will exceed 1000 amps for a few secs. In my airplane, all wires inside the cabin are attached to an ANL = that will melt before the insulation on the wire does. The only wires = that aren't protected that way are from the battery to the grid and from = the grid to the starter. If I were going to have batteries in the back I would probably put = in one of those big 7" cooper bussman ultra slow blow fuses. Then I = would be able to let the smoke out after 90 seconds or so. Colyn ----- Original Message -----=20 From: Clark Baker=20 To: lml@lancair.net=20 Sent: Friday, November 06, 2009 12:35 AM Subject: [LML] L-IVP Battery Cooling >>>Also, a remote location causes more voltage drop due to the longer = cable. I have one battery in the back and tried copper wire (very = heavy) and had almost no voltage drop, but when I checked aluminum wires = (very light), I had nearly 1.0v drop from the terminals to the Buss. = Aluminum is OK for avionics Buss, but not cranking or hydralic pump amp = (too much heat and volt loss), if drawing off a battery behind the rear = bulkhead. My humble opinion. <
Clark,
    sounds like good=20 stuff!
 
    I think Eric is = right in=20 general about the battery not being able to melt the wire but I suggest = you look=20 at the battery specs e.g. at odyssey and see how impressive their short = term=20 currents really are.  e.g. you can be over 200 amps for 30 secs = going=20 through a starter.  If you size it big enough, Eric is=20 right.   If it's not big enough you could definitely melt it=20 down.    If you get a dead short across the wires then it = will be=20 way higher current for way less time.  e.g. I think a odyssey pc680 = will=20 exceed 1000 amps for a few secs.
    In my airplane, all = wires inside=20 the cabin are attached to an ANL that will melt before the insulation on = the=20 wire does.  The only wires that aren't protected that way are from = the=20 battery to the grid and from the grid to the starter.
    If I were going to = have=20 batteries in the back I would probably put in one of those big 7" cooper = bussman=20 ultra slow blow fuses.   Then I would be able to let the smoke = out=20 after 90 seconds or so.
 
Colyn
 
 
----- Original Message -----
From:=20 Clark = Baker=20
Sent: Friday, November 06, 2009 = 12:35=20 AM
Subject: [LML] L-IVP Battery=20 Cooling

>>>Also, a remote location causes more voltage drop due = to the=20 longer cable.  I have one battery in the back and tried copper = wire (very=20 heavy) and had almost no voltage drop, but when I checked aluminum = wires (very=20 light), I had nearly 1.0v drop from the terminals to the Buss.  = Aluminum=20 is OK for avionics Buss, but not cranking or hydralic pump amp (too = much heat=20 and volt loss), if drawing off a battery behind the rear = bulkhead.  My=20 humble opinion.

<<My=20 plan therefore is to make sure something else opens or fuses before = the wire=20 melts down.<<

I was curious about the statements above since I am using CCA = (copper=20 clad aluminum) battery wiring in my Legacy.  Below are comments = from Eric=20 Jones at Perihelion Designs.

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