Return-Path: Received: from [65.54.168.111] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.3c1) with ESMTP id 742361 for flyrotary@lancaironline.net; Wed, 16 Feb 2005 23:35:23 -0500 Received-SPF: pass receiver=logan.com; client-ip=65.54.168.111; envelope-from=lors01@msn.com Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Wed, 16 Feb 2005 09:59:01 -0800 Message-ID: Received: from 4.174.3.22 by BAY3-DAV7.phx.gbl with DAV; Wed, 16 Feb 2005 17:58:10 +0000 X-Originating-IP: [4.174.3.22] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Battery voltage (was: Racetech RV6A Forced Landing) Date: Wed, 16 Feb 2005 12:58:12 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0087_01C51427.2BC8B0E0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 X-MimeOLE: Produced By MSN MimeOLE V9.10.0011.1703 Seal-Send-Time: Wed, 16 Feb 2005 12:58:12 -0500 X-OriginalArrivalTime: 16 Feb 2005 17:59:01.0148 (UTC) FILETIME=[31DE35C0:01C51451] This is a multi-part message in MIME format. ------=_NextPart_000_0087_01C51427.2BC8B0E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable My voltage alarm is set to go off at around 13.5 volts. This is higher = than a fully charged battery. In other words, alarm goes off the = instant that the alternator fails. System voltage is about 14.2 volts = under normal conditions. It is amazing that people with a complete understanding of how critical = electrical system is on an EFI aircraft engine would install an alarm = light so small or positioned in such a way that it would not be noticed. = I would have to be brain dead not to notice mine. I have had one = alternator failure which occurred almost immediately after engine start = (this seems to be common). The alarm went off and I taxied back to the = hangar. My reaction was not to install another 30 to 40 pounds of = electrical stuff on the aircraft. Tracy George, Most of the motorcycles will still show at least 11 volts while = cranking and those are small batteries. They will jump back up to at = least 12.5 after cranking. I agree that 9.5 volts is almost totally dead = for practical purposes. Most battery based systems will have trouble at = around 10 volts. Use a backup battery and a changeover system with any = electrically based system. The EXP Buss (I think) is sold by the = anywhere map people. Makes it very easy to set up a battery backup = system and still charge both. I think Eggenfellner also sells them. Good = looking product, a good friend has one.=20 For battery info go to the Yuasa web site. In the technical section = they have a excellent do's and don'ts of battery operation. There is = also a good description of the different battery types and their = discharge rates. Good info to know about this VITAL system part! Bill Jepson=20 In a message dated 2/15/2005 11:34:28 PM Pacific Standard Time, = lendich@optusnet.com.au writes: Bill, What would you expect the battery to show under starting load. George ( down under) > > > I suspected a charging system failure immediately and checked = the > >battery voltage in the SDS monitor. This read 9.5 volts so I knew = then that > >we had a charging system failure. At the time, I was not worried = about > >making it to an airport, assuming that the alternator had failed = just in the > >last few minutes and believing that I had 20-25 minutes of = battery power > >remaining. In fact, it is likely that the alternator failed soon = after > >takeoff from Springbank but I did not notice signs of the failure = until the > >battery was well over half dead. ------=_NextPart_000_0087_01C51427.2BC8B0E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
My voltage alarm is set to go off at around 13.5 volts.  = This is=20 higher than a fully charged battery.  In other words, alarm = goes off=20 the instant that the alternator fails.  System voltage is about = 14.2 volts=20 under normal conditions.
 
It is amazing that people with a complete understanding of how = critical electrical system is on an EFI aircraft engine would install an = alarm=20 light so small or positioned in such a way that it would not be = noticed.  I=20 would have to be brain dead not to notice mine.  I have had one = alternator=20 failure which occurred almost immediately after engine start (this seems = to be=20 common).  The alarm went off and I taxied back to the hangar.  = My=20 reaction was not to install another 30 to 40 pounds of electrical stuff = on the=20 aircraft.
 
Tracy
George,
 Most of the motorcycles will still show at least 11 volts = while=20 cranking and those are small batteries. They will jump back up to at = least=20 12.5 after cranking. I agree that 9.5 volts is almost totally dead for = practical purposes. Most battery based systems will have trouble at = around 10=20 volts. Use a backup battery and a changeover system with any = electrically=20 based system. The EXP Buss (I think) is sold by the anywhere map = people. Makes=20 it very easy to set up a battery backup system and still charge both. = I think=20 Eggenfellner also sells them. Good looking product, a good friend has = one.=20
 For battery info go to the Yuasa web site. In the = technical=20 section they have a excellent do's and don'ts of battery operation. = There is=20 also a good description of the different battery types and their = discharge=20 rates. Good info to know about this VITAL system part!
Bill Jepson 
 
In a message dated 2/15/2005 11:34:28 PM Pacific Standard Time,=20 lendich@optusnet.com.au writes:
Bill,
What would you expect the battery to show under = starting=20 load.
George ( down under)

>
> >  I = suspected a=20 charging system failure immediately and checked the
> = >battery=20 voltage in the SDS monitor. This read 9.5 volts so I knew=20 then
that
> >we had a charging system failure. At the = time, I=20 was not worried about
> >making it to an airport, assuming = that the=20 alternator had failed just in
the
> >last few minutes = and=20 believing that I had 20-25 minutes of battery power
> = >remaining.=20 In fact, it is likely that the alternator failed soon after
>=20 >takeoff from Springbank but I did not notice signs of the = failure=20 until
the
> >battery was well over half=20 dead.
 
------=_NextPart_000_0087_01C51427.2BC8B0E0--