REFLECTOR: Odyssey Battery

Andy Millin amillin at sbcglobal.net
Fri May 11 15:10:15 CDT 2007 

Hiroo,

There are any number of situations that one can think of that might prevent
you from landing at the nearest field with an instrument approach.

The first could be that the airports around you are below minimums.  An
instrument approach won't get you in.  You may have to divert to your
alternate, or possibly return home.  Stuff happens that wasn't supposed to
be there according to the briefer man.  Been there, done that.

When we took Bob Nuckoll's class he emphasized having early detection of
alternator failure AND carrying more battery on the essential bus than you
have fuel in your tanks.  Essentially, as long as you have fuel in your
tank, your essential instruments will stay up.

Having the capability can increase options.  Like most things it comes down
to your personal minimums, what you want, and what you feel you need to
have.

The runway behind you, the altitude above you, the gas you left at the pump,
and now the electrons you didn't squirrel away...

Andy

-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of Hiroo Umeno
Sent: Friday, May 11, 2007 3:55 PM
To: Velocity Aircraft Owners and Builders list
Subject: Re: REFLECTOR: Odyssey Battery

I don't have IFR experience yet so I might be missing something but...

Why do you need 2 hours?  Unless you are over open water or in the
wilderness of Alaska, you are never too far from an airfield with an IFR
approach, right?  So, if your "Low Voltage" light or "Alternater Failure"
light comes on, then the process should be...

1.  Declare emergency to whomever you are currently talking to...
2.  Get vectors to the nearest airfield with IFR approach...
3.  Get yourself down.

With an average speed of a Velocity at 160Kts or more, you should be able to
get down under most situation in 30 minutes or less, no?

On my plane, I installed a secondary battery (motorcycle kind) that kicks in
when the mains go flat.  So the sequence of event on mine would look like...

1.  Alternator failure light comes on. (Annunciator Panel) - Alternator is
no longer supplying 13.5V or above to the bus.
2.  Low Voltage warning. (EFIS Alert) - Main battery getting low.
3.  Standby battery kicks in (Annunciator indicates Backup Battery) - Main
bus is isolated.  EFIS, panel lighting and Radios getting power 4.
Everything goes dark.

I am hoping this is enough warning to "get me down in a hurry".

The only thing about the way I did the electrical is that once the main bus
isolation kicks in, I will lose the ability to use any of the external
lighting (NAV, Strobe, Landing Lights, etc).

I will need to find a lighted field to land in.

Hiroo

-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of Chuck Jensen
Sent: Friday, May 11, 2007 12:11 PM
To: Velocity Aircraft Owners and Builders list
Subject: Re: REFLECTOR: Odyssey Battery

Larry,

Good advice all.  Fortunately, the GRT EFIS provides for alarming multiple
voltage points, so an alternator going off line will put an alarm on the
screen and I have a flashing red light for a separate alarm, though it
doesn't put out an audio alarm to the head sets.  One would hope that 2
hours is sufficient to escape IFR and with prompt load shedding, perhaps 3
or more.  Still, juice is like money...more is always better.

Chuck Jensen

-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of Laurence Coen
Sent: Friday, May 11, 2007 2:57 PM
To: Velocity Aircraft Owners and Builders list
Subject: Re: REFLECTOR: Odyssey Battery


Chuck,

I use the Optima D34 (deep discharge version) like Pat.  I also did a
battery rundown test to check the real world expectation as opposed to the
theoretical.  During simulated night flight, two hours is all I got if I

didn't shed load.  When the buss voltage hits 10V, your radios stop working.
In IFR this is not good.  The battery isn't really "dead" but you are a no
radio flight.  The unfortunate truth about alternator failure is that it's
noticed when the radios go dead. Too late!  The other thing that often
happens is that the alternator partially fails and the battery slowly
discharges with each flight.  This means when the alternator finally gives
up the ghost your battery is already dead.  What I'm trying to say is keep
the volt and ammeter in your scan and understand what they're telling you.
If you suspect a problem, shed load as much and as fast as you can.
whatever is gone isn't coming back.

Larry Coen
N136LC

----- Original Message -----
From: "Chuck Jensen" <cjensen at dts9000.com>
To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org>
Sent: Wednesday, May 09, 2007 1:23 AM
Subject: Re: REFLECTOR: Odyssey Battery


> Keith,
>
> I concur with the two different missions for the battery, though I 
> understand the PC 680, in good condition, should be adequate for both 
> missions; namely cranking an IO 540 as well as provide escape time 
> from IFR electrical failure.  The IFR escape capacity of the battery 
> holds importance to me.  The PC 680, in good condition, seems to have 
> the 17 AH seems adequate to "get home" if the electrons stop birthing 
> and several parties report the 680 CA is amply to spin the IO 540, so 
> I'm going to give it a go.
>
> My current FLA battery is getting to the point that even after a good 
> charging flight, the next day it just barely makes the start, though 
> it always has.  Of course, when I install the PC 680, if I still have 
> the same problem, then I'll know to look elsewhere.  I believe this 
> process is known as being a "parts replacer" rather than a mechanic.
> Of course, being a parts replacer makes me qualified to work in most 
> any automotive shop these days!
>
> And Pat, looking at your 38# monster battery, I'm thinking if your 
> alternator goes out, that you'll just have to remember to fix it after

> two or three days of flying.  It's got enough juice to get you home, 
> back again and home again.
>
> Chuck Jensen
>
>
> -----Original Message-----
> From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org]
> On Behalf Of Keith Hallsten
> Sent: Tuesday, May 08, 2007 9:52 PM
> To: 'Velocity Aircraft Owners and Builders list'
> Subject: Re: REFLECTOR: Odyssey Battery
>
>
> Chuck,
>
> Sure - even a very small sealed lead-acid battery will crank the 
> engine... However, if you file IFR or fly at night and don't have a 
> back-up alternator you should consider establishing a minimum capacity

> for the battery that will be sufficient to get you to your intended 
> destination without breaking a sweat.  That's an entirely different 
> question and will depend on your enroute electrical loads for, say, 
> night flight.  If you stick to day VFR, this is not a significant 
> consideration unless you have an electrically dependant engine (EFI, 
> electrical fuel pump only).
>
> Keith
>
>
> -----Original Message-----
> From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org]
> On Behalf Of Chuck Jensen
> Sent: Tuesday, May 08, 2007 4:16 PM
> To: Velocity Aircraft Owners and Builders list
> Subject: REFLECTOR: Odessey Battery
>
> Is the Odessey PC 680 battery sufficient to crank the IO-540?
>
> Chuck Jensen
>
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