REFLECTOR: It's been really quiet this week

Mon Feb 17 12:44:43 CST 2014

Brian,

While I cannot help you with your battery issue I would like to know more
about your injection system. I am considering a different injection system
for my Franklin. Currently it has a Continental system that does not work
well. Any suggestions would be appreciated.

Grover McNair

From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of Brian Michalk
Sent: Monday, February 17, 2014 12:45 PM
To: Velocity Aircraft Owners and Builders list
Subject: Re: REFLECTOR: It's been really quiet this week

I've been flight testing.  It's a slow process for me, since my engine
design while Franklin based, has EFI and EI.
I have been battling high CHT's even in the cooler weather, and am seeing
positive results as the engine breaks in.

Specifically, I've been testing the forward CG limits, and have decided that
my decision to move equipment as far forward as possible was a bad one.  I
was intending to have Juanita be able to fly the airplane without ballast,
but with my weight, I can't really carry much in the copilot seat.  I
mounted a big Optima Red Top at a 15 inch arm location.  This weekend I
relocated it temporarily to just forward of the whales tail, but for a
permanent solution, I am looking at some of the really lightweight batteries
that are out there, and am having a hard time making up my mind.

Option 1: some lightweight lead/acid battery
Option 2: an alternative chemistry

For option 1, John mentioned the Braille batteries.  I looked online, and
people seem to think that Braille is stretching their performance numbers,
but if Velocity is using them, then that's a pretty good endorsement.  There
are also Odyssey batteries that look pretty good as well.

Option 2 for me would be the new LiFe (Lithium Iron) batteries that are used
in some motorcycles, snowmobiles and jet skis.  Those are all pretty high
vibration environments, which was my first concern.  Next, they are really
incredibly lightweight.
Now, when these batteries reach 13 volts, they are basically dead, with 30%
capacity remaining.  They are fully charged at 14.3 volts, and appear to
take a charging voltage up to 15 volts.  For me, I'd need to convert my
internal regulated alternator to external, and bump up the voltage to
accommodate these new batteries.
Another down side is, like the LiPo batteries, these need to have the cells
balanced.  There is a special connector that ensures all of the cells are
charged to their proper voltage, but balancing a battery doesn't have to be
performed for every charge.  I also think that rather than charging through
the balancing port, a person could use a hobby grade balancer that places a
load on cells to draw down their voltage, achieving the same goal.  Bulk
charge through the terminals, then balance by discharging excess capacity.
And another downside is that they like to be stored at something like 80%
capacity.  This may be fine for our needs.  As long as they can start the
plane, they can be charged at high currents, so within a few minutes after
starting they would be at 100%.
Okay.  For one final upside:  The higher operating voltage will spin a prop
faster, and will have smaller voltage drop in your cables.  I'm solid state
switching, losing a couple of tenths of volts across each solid state relay.
This bump up in voltage would really be nice for my electric gyros, which
are always complaining about low voltage until I bring up the engine RPM's.

LFX19A4-BS12MSRP: $199.95 

SHORAI LFX Lithium-ion Powersports battery,19AH 12V, "A" polarity, Case Type
4
Length 5.83" 
Width 3.39"
Height 3.46"
Weight 2.32lbs
CCA 285amps

I would need two of those, which would put me at the lower end of my CCA
requirements.
www.shoraipower.com <http://www.shoraipower.com> 

On 02/17/2014 08:29 AM, Reiff Lorenz wrote:

The Reflector has been so quiet the past 5 days. I've been busy traveling
for work and tackling home renovation projects that I have not been building
much. (One of my trips was to Seattle, though, and I stayed an extra day
with Clay Chase to work on his kit, so I guess that counts as building time;
just not on my plane!)

Hope everyone else is finding more time than I am to build or fly.

Reiff Lorenz, Dayton, OH

Velocity XL-RG, 53% complete

Currently working on: March issue of Velocity News

_______________________________________________
To change your email address, visit
http://www.tvbf.org/mailman/listinfo/reflector

Visit the gallery!  www.tvbf.org/gallery <http://www.tvbf.org/gallery> 
user:pw = tvbf:jamaicangoose
Check new archives: www.tvbf.org/pipermail <http://www.tvbf.org/pipermail> 
Check old archives: http://www.tvbf.org/archives/velocity/maillist.html

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.tvbf.org/mailman/private/reflector/attachments/20140217/59214857/attachment.html>