Today's Message Index:
----------------------
1. 11:29 AM - battery selection (Stan Loer)
2. 12:03 PM - Re: battery selection (Carl Froehlich)
3. 12:05 PM - Re: battery selection (Larry Bowen)
4. 12:36 PM - Re: battery selection (Carl Froehlich)
5. 12:59 PM - Re: battery selection (Larry Bowen)
6. 02:18 PM - Re: battery selection (Carl Froehlich)
Message 1
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Subject: | battery selection |
Has anyone installed the Odyssey PC625 battery? I know that the PC680
is more common, but I'm looking at a dual installation with one battery
forward and the other aft. The 625 is slightly smaller and lighter than
the 680. My 8 will be all electric, no steam gauges, and set up for
day/night VFR, so a dual battery installation makes more sense to me
than a back-up alternator. Seems to me that dual paralleled PC625
batteries should provide plenty of get-home power in case of an
alternator failure, even at night, but my electrical expertise is
limited and I'll take all the help I can get.
While I'm at it, a question re ELT mount locations. I've seen several
mounted on the "hat shelf". This is tempting as it's very
convenient, but the shelf is kinda flimsy. Beef it up? I'm also
looking at possibly mounting it on brackets off the side of the aft
battery box. More complex, but maybe a better choice.
Message 2
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Subject: | battery selection |
This is exactly what I have in my 8A (700 hrs), two PC625 batteries.
The
battery has almost identical performance to the PC680 but a much better
form
factor for my install. I have both mounted just aft of the firewall,
one on
each side. I too have an all electric panel. I have done tests to
demonstrate the batteries will support 2 and =BD hours of IFR flight
with no
alternator (the design target). I change out one battery every two
years
just to make sure they are up to snuff (no battery is more than 4 years
old). I have one of the old batteries in my lawn tractor now for 6
years '
and it still cranks it right up after sitting all winter. I also am
using
two PC625s in my RV-10.
I mounted the ELT on the shelf. I also mount a 15 pound tool/survival
bag
on the shelf. It handles both with no issues (max G load so far is 4
from a
poorly executed loop). The ELT antenna is mounted under the empennage
fairing.
Carl
From: owner-rv8-list-server@matronics.com
[mailto:owner-rv8-list-server@matronics.com] On Behalf Of Stan Loer
Sent: Friday, January 27, 2012 2:27 PM
Subject: RV8-List: battery selection
Has anyone installed the Odyssey PC625 battery? I know that the PC680
is
more common, but I'm looking at a dual installation with one battery
forward
and the other aft. The 625 is slightly smaller and lighter than the
680.
My 8 will be all electric, no steam gauges, and set up for day/night
VFR, so
a dual battery installation makes more sense to me than a back-up
alternator. Seems to me that dual paralleled PC625 batteries should
provide
plenty of get-home power in case of an alternator failure, even at
night,
but my electrical expertise is limited and I'll take all the help I can
get.
While I'm at it, a question re ELT mount locations. I've seen several
mounted on the "hat shelf". This is tempting as it's very
convenient, but the shelf is kinda flimsy. Beef it up? I'm also
looking
at possibly mounting it on brackets off the side of the aft battery box.
More complex, but maybe a better choice.
Message 3
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Subject: | Re: battery selection |
Can't help you on the battery, I've only used the 680.
I'll have all glass and dual LSI in the RV-7, and I'm actually considering
one alt and one battery. Crazy, or just practical? TBD...
In the RV-8, I put my Pointer ELT under the VS. No added structure needed
and helped a little with fwd CG.
Cheers,
--
Larry Bowen
Larry@BowenAero.com
http://BowenAero.com
On Fri, Jan 27, 2012 at 2:26 PM, Stan Loer <stazel@cpros.com> wrote:
> **
> Has anyone installed the Odyssey PC625 battery? I know that the PC680 is
> more common, but I'm looking at a dual installation with one battery
> forward and the other aft. The 625 is slightly smaller and lighter than
> the 680. My 8 will be all electric, no steam gauges, and set up for
> day/night VFR, so a dual battery installation makes more sense to me than a
> back-up alternator. Seems to me that dual paralleled PC625 batteries
> should provide plenty of get-home power in case of an alternator failure,
> even at night, but my electrical expertise is limited and I'll take all the
> help I can get.
>
> While I'm at it, a question re ELT mount locations. I've seen several
> mounted on the "hat shelf". This is tempting as it's very
> convenient, but the shelf is kinda flimsy. Beef it up? I'm also looking
> at possibly mounting it on brackets off the side of the aft battery box.
> More complex, but maybe a better choice.
>
> *
>
> *
>
>
Message 4
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Subject: | battery selection |
No backup battery on a LightSpeed ignition install is not practical.
For no a backup battery system (or one with a back up battery) a dual P-Mags
install is a better approach. If you want, I can tell you the name of the
person I gave my dual Lightspeeds to when I yanked them off my 8A (replaced
with P-Mags). You can get them real cheap.
Carl
From: owner-rv8-list-server@matronics.com
[mailto:owner-rv8-list-server@matronics.com] On Behalf Of Larry Bowen
Sent: Friday, January 27, 2012 3:03 PM
Subject: Re: RV8-List: battery selection
Can't help you on the battery, I've only used the 680.
I'll have all glass and dual LSI in the RV-7, and I'm actually considering
one alt and one battery. Crazy, or just practical? TBD...
In the RV-8, I put my Pointer ELT under the VS. No added structure needed
and helped a little with fwd CG.
Cheers,
--
Larry Bowen
Larry@BowenAero.com
http://BowenAero.com
On Fri, Jan 27, 2012 at 2:26 PM, Stan Loer <stazel@cpros.com> wrote:
Has anyone installed the Odyssey PC625 battery? I know that the PC680 is
more common, but I'm looking at a dual installation with one battery forward
and the other aft. The 625 is slightly smaller and lighter than the 680.
My 8 will be all electric, no steam gauges, and set up for day/night VFR, so
a dual battery installation makes more sense to me than a back-up
alternator. Seems to me that dual paralleled PC625 batteries should provide
plenty of get-home power in case of an alternator failure, even at night,
but my electrical expertise is limited and I'll take all the help I can get.
While I'm at it, a question re ELT mount locations. I've seen several
mounted on the "hat shelf". This is tempting as it's very
convenient, but the shelf is kinda flimsy. Beef it up? I'm also looking
at possibly mounting it on brackets off the side of the aft battery box.
More complex, but maybe a better choice.
et="_blank">http://www.matronics.com/Navigator?RV8-List
tp://forums.matronics.com
_blank">http://www.matronics.com/contribution
Message 5
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Subject: | Re: battery selection |
I'm already committed to the dual LSI. PMags were still wet behind the
ears when I made the decision.
Alternator is primary, main battery is backup. How is that not practical?
Educate me.
--
Larry Bowen
Larry@BowenAero.com
http://BowenAero.com
On Fri, Jan 27, 2012 at 3:33 PM, Carl Froehlich
<carl.froehlich@verizon.net>wrote:
> No backup battery on a LightSpeed ignition install is not practical. ****
>
>
> For no a backup battery system (or one with a back up battery) a dual
> P-Mags install is a better approach. If you want, I can tell you the name
> of the person I gave my dual Lightspeeds to when I yanked them off my 8A
> (replaced with P-Mags). You can get them real cheap.****
>
>
> Carl****
>
> ** **
>
> *From:* owner-rv8-list-server@matronics.com [mailto:
> owner-rv8-list-server@matronics.com] *On Behalf Of *Larry Bowen
> *Sent:* Friday, January 27, 2012 3:03 PM
> *To:* rv8-list@matronics.com
> *Subject:* Re: RV8-List: battery selection****
>
> ** **
>
> Can't help you on the battery, I've only used the 680. ****
>
> ** **
>
> I'll have all glass and dual LSI in the RV-7, and I'm actually considering
> one alt and one battery. Crazy, or just practical? TBD...****
>
> ** **
>
> In the RV-8, I put my Pointer ELT under the VS. No added structure needed
> and helped a little with fwd CG.****
>
> ** **
>
> Cheers,****
>
>
> --
> Larry Bowen
> Larry@BowenAero.com
> http://BowenAero.com
>
>
> ****
>
> On Fri, Jan 27, 2012 at 2:26 PM, Stan Loer <stazel@cpros.com> wrote:****
>
> Has anyone installed the Odyssey PC625 battery? I know that the PC680 is
> more common, but I'm looking at a dual installation with one battery
> forward and the other aft. The 625 is slightly smaller and lighter than
> the 680. My 8 will be all electric, no steam gauges, and set up for
> day/night VFR, so a dual battery installation makes more sense to me than a
> back-up alternator. Seems to me that dual paralleled PC625 batteries
> should provide plenty of get-home power in case of an alternator failure,
> even at night, but my electrical expertise is limited and I'll take all the
> help I can get. ****
>
> ****
>
> While I'm at it, a question re ELT mount locations. I've seen several
> mounted on the "hat shelf". This is tempting as it's very ****
>
> convenient, but the shelf is kinda flimsy. Beef it up? I'm also looking
> at possibly mounting it on brackets off the side of the aft battery box.
> More complex, but maybe a better choice. ****
>
> * *
>
> * *
>
> *et="_blank">http://www.matronics.com/Navigator?RV8-List*
>
> *tp://forums.matronics.com*
>
> *_blank">http://www.matronics.com/contribution*
>
> * *
>
> ** **
>
> * *
>
> * *
>
> **
>
> **
>
> **
>
> **
>
> **
>
> *http://www.matronics.com/Navigator?RV8-List*
>
> **
>
> **
>
> *http://forums.matronics.com*
>
> **
>
> **
>
> **
>
> **
>
> *http://www.matronics.com/contribution*
>
> **
>
> * *
>
> *
>
> *
>
>
Message 6
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Subject: | battery selection |
In a single alternator, single battery install the battery is primary and
the alternator charges the battery, it is not a backup to the battery. I
few thoughts:
1. Look at where your alternator connects to your battery. I offer
that there are at least two points in the system where a single post failing
(loose, melted, shorted) takes down your entire electrical system. Not long
ago a twin engine plane (two alternators and two batteries) had a total loss
of electrical power when the common post on the master relay failed.
2. Look at the single post for ground on your battery. Again a single
failure will lead to total loss of power.
3. Many alternator installs do not run well without a battery floating
on them for reference (source) voltage. Some do, some don't.
4. For a simple example your master relay fails open. Unless you have
dedicated auxiliary feeds from the battery you have lost all power.
I suspect many dual battery installs have only increase capacity to offer,
not added redundancy. Again the objective is to not have a single failure
bring down all your power. It is the system that counts, not the individual
components.
The most reliable electrical component in your plane is the battery. This
is why I have two batteries feeding independent master relays and dedicated
smaller relays for the panel, and a single alternator. The odds of an
alternator failing (I had two go south in my 8A over the last 9 years) is
way higher than a battery failing in flight. Now if you crank a battery(s)
into the dirt and then take off hoping the alternator will charge it (before
the alternator craps out), you are just asking for trouble.
For a dual Lightspeed install some sort of battery backup for the ignition
is mandatory. The simple Panasonic battery with the diode isolation as
illustrated in Klaus' manual is the bare minimum. It will at least let you
land at the closest runway instead of an engine out landing in a field. For
an all electric panel, redundant power is mandatory as well.
BTW - I took a look at your website link. So you know, the Lightspeed
ignition box generates some heat. As you have them mounted back to back you
might want to give Klaus a call to see if this reduction in heat transfer
surface is a problem or not. In my 8A I had them mounted aft of the fire
wall on spacers to allow air to get at the back of the box. I also had
insulation on the cabin side of the firewall to isolate engine heat.
Carl
From: owner-rv8-list-server@matronics.com
[mailto:owner-rv8-list-server@matronics.com] On Behalf Of Larry Bowen
Sent: Friday, January 27, 2012 3:57 PM
Subject: Re: RV8-List: battery selection
I'm already committed to the dual LSI. PMags were still wet behind the ears
when I made the decision.
Alternator is primary, main battery is backup. How is that not practical?
Educate me.
--
Larry Bowen
Larry@BowenAero.com
http://BowenAero.com
On Fri, Jan 27, 2012 at 3:33 PM, Carl Froehlich <carl.froehlich@verizon.net>
wrote:
No backup battery on a LightSpeed ignition install is not practical.
For no a backup battery system (or one with a back up battery) a dual P-Mags
install is a better approach. If you want, I can tell you the name of the
person I gave my dual Lightspeeds to when I yanked them off my 8A (replaced
with P-Mags). You can get them real cheap.
Carl
From: owner-rv8-list-server@matronics.com
[mailto:owner-rv8-list-server@matronics.com] On Behalf Of Larry Bowen
Sent: Friday, January 27, 2012 3:03 PM
Subject: Re: RV8-List: battery selection
Can't help you on the battery, I've only used the 680.
I'll have all glass and dual LSI in the RV-7, and I'm actually considering
one alt and one battery. Crazy, or just practical? TBD...
In the RV-8, I put my Pointer ELT under the VS. No added structure needed
and helped a little with fwd CG.
Cheers,
--
Larry Bowen
Larry@BowenAero.com
http://BowenAero.com
On Fri, Jan 27, 2012 at 2:26 PM, Stan Loer <stazel@cpros.com> wrote:
Has anyone installed the Odyssey PC625 battery? I know that the PC680 is
more common, but I'm looking at a dual installation with one battery forward
and the other aft. The 625 is slightly smaller and lighter than the 680.
My 8 will be all electric, no steam gauges, and set up for day/night VFR, so
a dual battery installation makes more sense to me than a back-up
alternator. Seems to me that dual paralleled PC625 batteries should provide
plenty of get-home power in case of an alternator failure, even at night,
but my electrical expertise is limited and I'll take all the help I can get.
While I'm at it, a question re ELT mount locations. I've seen several
mounted on the "hat shelf". This is tempting as it's very
convenient, but the shelf is kinda flimsy. Beef it up? I'm also looking
at possibly mounting it on brackets off the side of the aft battery box.
More complex, but maybe a better choice.
et="_blank">http://www.matronics.com/Navigator?RV8-List
tp://forums.matronics.com
_blank">http://www.matronics.com/contribution
http://www.matronics.com/Navigator?RV8-List
http://forums.matronics.com
http://www.matronics.com/contribution
et="_blank">http://www.matronics.com/Navigator?RV8-List
tp://forums.matronics.com
_blank">http://www.matronics.com/contribution
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