Today's Message Index:
----------------------
0. 12:12 AM - Please Make A Contribution To Support Your Lists (Matt Dralle)
1. 04:09 AM - Radio Transmits Poorly Only When On The Ground (DaveG601XL)
2. 04:44 AM - Re: lithium facts (Henador Titzoff)
3. 10:33 AM - Re: lithium facts (Robert L. Nuckolls, III)
4. 11:50 AM - Re: Radio Transmits Poorly Only When On The Ground (Charlie England)
5. 01:48 PM - Re: lithium facts (Charlie England)
6. 02:48 PM - Re: Radio Transmits Poorly Only When On The Ground (Cherie&Ken)
7. 05:30 PM - Re: lithium facts (Robert L. Nuckolls, III)
8. 05:34 PM - Re: Radio Transmits Poorly Only When On The Ground (Robert L. Nuckolls, III)
9. 09:50 PM - Re: lithium facts (Stuart Ashley)
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Subject: | Please Make A Contribution To Support Your Lists |
Dear Listers,
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Message 1
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Subject: | Radio Transmits Poorly Only When On The Ground |
I have a gremlin that I don't know how to troubleshoot. I have a 601XL all-metal
airplane with an Icom A-200 radio, a RAMI com antenna mounted on the top skin
and connected with RG-400 cable. I did all the installation myself. I have had
this flying for 6 years now. It transmits just fine in the air, but when I
initially installed it, I would get comments that it was a bit garbled while transmitting
on the ground. It was always good enough though, as I could still
carry on a 2-way conversation, plus I was able to operate out of tower controlled
airports and not get any negative radio comments. Receiving wise, I have always
been able to hear just fine whether on the ground or in the air.
Just this summer, I started to get comments from fellow pilots that I was totally
unreadable while transmitting on the ground. It would become crystal clear
as soon as I took off. Does anyone have any thoughts of why this could be occurring
or any place in particular I should start my troubleshooting??
Thanks,
--------
David Gallagher
Zodiac 601 XL-B: flying, 280+ hours now
Next project under construction: Finish my father's Aircamper
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=432802#432802
Message 2
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Subject: | Re: lithium facts |
>________________________________
>
>On Sun, Nov 2, 2014 at 2:11 PM, Robert L. Nuckolls, III <nuckolls.bob@aeroelectric.com>
wrote:
>
>
>>My second point is: Could a simple solid state DC voltage regulator
be designed to bring the 16.8 V. down to 14.4 V? This would
maximize the potential of the lithium battery.
>>
>>
>> Bob, if a regulator were designed to bring the voltage down to 14.4V, it
>> would have to deal with the primary purpose of the battery - to start the
>> engine. That's a lot of amps, making the design more difficult, expensive
>> and of course, adding more weight.. It is also one more system to
>> maintain and possibly fail in flight.
>> --Henador
>>
>>This is exactly what the makers of computers, tablets,
>>cell phones, and other products do. They use chargers
>>designed for the battery voltage selected . . . and discharge
>>to switch-mode power supplies that offers the desired system
>>voltage. Unfortunately, our 'charger' is that belt driven
>>thingy up front that is not especially tailored to the
>>care and feeding of lithium. Even if it were, then yes, we'd
>>need some mater of dc/dc converter to re-flavor the volts
>>to 14.4.
>>
>>
>> Bob, tablets and smartphones have two advantages in this
>> regard. First, they are neatly packaged and designed to
>> work with a single design per device. This means that the
>> designers maximize all parameters to prevent EMI, and
>> EMS and power utlization.
>>
>>
>> Second, once the design is "thoroughly" tested, they make
>> gazillions of the same thing. Our experimental airplanes are
>> one of a kind, which means each one is a different design,
>> electrical-wise. We don't have good control of EMI, EMS
>> and power utilization across our experimental fleets as it is.
>> And of course, it will add weight, more maintenance and
>> decrease system reliability.
>> --Henador
>>The thrust of my articles is to explore the cost/benefit
>>ratio for 'going lithium'. After you've spent the dollars
>>for the premium product, can you get off shorter runways,
>>fly over taller mountains, endure longer with a failed
>>alternator, or carry more baggage?
>>
>>
>> Bob, you might be able to, because your wallet will weigh
>> less.
>> --Henador
>>
>>
Message 3
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Subject: | Re: lithium facts |
At 18:29 2014-11-02, you wrote:
>Ken,
>
>You missed one question: How does the
>performance of Li battery technology compare to
>Pb with respect to maintaining our necessary
>electronic equipment (aka electro-whizzies)
>until we can make a safe return to terra
>firma. That was the area of greatest deficiency
>I found when doing my brief evaluation.
The present studies are focused on understanding
the capabilities and limits of the lithium technologies
and systems integration issues to be resolved.
There is no answer to your question based purely
on chemistry or application. I was asked by a
supplier of lithium products to help them craft
an application chart . . . a table of various
OBAM aircraft/engines with boxes citing the
recommended lithium product.
I'm not sure they really understood my reluctance
to participate in such an adventure. My advice to
them was simple. Tell the customer EVERYTHING they
need to know to integrate the technology into their
project and how to SIZE it to the task as defined
by that customer's design goals.
I took them to task for that "lead-acid equivalency"
bull-hocky with a suggestion that they were hanging
their fanny way out in the breeze for a lawsuit.
The widow of some pilot downed in the mountains might
have a foundation in PHYSICS to hypothesize that
"Your recommendation of lithium product Z to replace
my husband's lead-acid product X was the proximate
cause of his panel going dark 30 minutes sooner than
if he had NOT followed your recommendation."
At the same time, the OBAM aviation community has both
opportunity and encouragement to gather ALL the
details necessary to make the change-out . . . based
on personal design goals . . . not some poorly
crafted substitution chart offered by the manufacturer.
Patience my friend. We're learning more every day
but data upon which your question depends is not
yet in hand.
At 18:04 2014-11-02, you wrote:
Bob,
It seems to me that your question "can you get
off shorter runways, fly over taller mountains,
endure longer with a failed alternator, or carry
more baggage?" adds little to the discussion. I
say this because making an airplane light is
accomplished by many decisions to save small
amounts of weight by going with option B rather
than option A, option D rather than option C,
etc. The cumulative result of all of these
decisions does indeed allow one to get off
quicker, climb faster, carry more baggage, etc.
However, if we were to evaluate each decision
individually, as you seek to do with lithium
batteries, probably none of them achieve a
meaningful difference in aircraft performance.
The question to ask is not what the effect will
be on aircraft performance. We already know that.
This is no mystery. The question is already
answered, because every pound counts just as much
as every other pound when it comes to weight
related performance whether it be a lighter
battery, the choice of titanium over stainless
steel for the firewall, or the decision to go on
a diet to achieve a smaller beer belly. It seems
to me the important questions are "How does the
cost of lithium compare to the cost of lead
acid?" and "How does the safety of lithium
compare to the safety of lead acid?" Those
questions are important. Questions of weight
related aircraft performance are merely rhetorical.
No argument there. But for all of lithium's uber-hyped
features, WEIGHT is the big-bear in the woods. Okay,
sit down an make a list of ALL opportunities to reduce
aircraft empty weight in order of their probability
of implementation and costs. Hmm . . . carbon fiber
RV-7?. Aluminum IO-360? Smaller tires? Leave off the
brakes? Yeah, the list is silly . . . but I use it
to emphasize the fact that our airplanes are NOT clean
piece of paper designs where weight savings reighns
supreme over perhaps strength, handling qualities,
payload, cockpit comforts, etc. etc. I'm recalling
Voyager here . . . an airplane that needed 5 pounds of
fuel to carry 1 pound of airplane around the world.
Uncle Burt took the task so seriously that he installed
B&C regulators without their housings . . . the electronics
mounted to covers were stood up on spacers. Saved
a few ounces.
THAT approach to 1000 weight savings decisions go
directly toward success or failure of the mission.
But back in the RV builder's shop. Just how many
opportunities REALLY exist for reduction of weight?
The battery as a real chunk of lead/plastic is
an obvious candidate . . . so what size lithium
battery will DO EVERYTHING the existing lead-acid
battery is expected to do?
I am in the early stages of discovery that the
lithium product dropped into a lead-acid optimized
system is physically prevented from exploiting
the full capabilities of the contained chemistry. This
means that a direct lithium replacement might have to
be $TWICE$ as large as originally thought just to
store and deliver the same energy.
OUR discussions/investigations are not conducted
for the benefit of those who use a battery only
for engine cranking. I am operating under the
design goal of finding out exactly how many pounds
and cubic inches of lithium are required to make
a 1:1 change out.
Early discoveries suggest that the real numbers
for weight savings and costs are not nearly so
attractive as the ads would like us to believe.
All creative ventures from cooking to building
airplanes to crafting a good house paint call
for a knowledge of properties of materials and
management of energy.
Until we know those properties and how they
influence our energy management, the answer
is unclear. Finally, there are so few real
opportunities to reduce weight beyond selection
of bolt-on parts. So I'll suggest that the
prudent owner/operator's costs for making
the switch has little opportunity to make
observable improvements in aircraft performance.
Suggest you catch up on the lithium discussions
thus far with a review of first three articles
in Kitplanes and discussions here on the List
over the last year.
Bob . . .
Message 4
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Subject: | Re: Radio Transmits Poorly Only When On The Ground |
On 11/3/2014 6:06 AM, DaveG601XL wrote:
>
> I have a gremlin that I don't know how to troubleshoot. I have a 601XL all-metal
airplane with an Icom A-200 radio, a RAMI com antenna mounted on the top skin
and connected with RG-400 cable. I did all the installation myself. I have
had this flying for 6 years now. It transmits just fine in the air, but when
I initially installed it, I would get comments that it was a bit garbled while
transmitting on the ground. It was always good enough though, as I could still
carry on a 2-way conversation, plus I was able to operate out of tower controlled
airports and not get any negative radio comments. Receiving wise, I have
always been able to hear just fine whether on the ground or in the air.
>
> Just this summer, I started to get comments from fellow pilots that I was totally
unreadable while transmitting on the ground. It would become crystal clear
as soon as I took off. Does anyone have any thoughts of why this could be occurring
or any place in particular I should start my troubleshooting??
>
> Thanks,
>
> --------
> David Gallagher
> Zodiac 601 XL-B: flying, 280+ hours now
> Next project under construction: Finish my father's Aircamper
>
>
Everybody, or just some other pilots? I have a similar issue with my
MicroAir when in receive mode and flying within a few hundred feet of
another a/c. I'm pretty sure that the AGC (automatic gain control) in
the MicroAir doesn't have enough range to avoid overdriving its input
when the transmitting a/c is close. Other radios don't have this problem
in the same environment.
Charlie
Message 5
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Subject: | Re: lithium facts |
This sounds like 'a failure to communicate.'
There would be no electrical performance advantage to Lithium (either
will crank the engine), and there could (likely) be a disadvantage (in
endurance). So for me, it really boils down to whether the weight
savings is worth the pounds saved, and whether the pounds saved is worth
the likely reduction in endurance and the unknown increase in risk due
to failure (fire).
Now if I could add a second alternator with its controls (for unlimited
endurance) and combined with the lithium starting battery, weigh the
same or less than single alternator & lead-acid battery, that would
begin to tip the scales toward lithium. But the the money and safety
questions remain to be resolved.
Charlie
On 11/2/2014 6:04 PM, Ken Ryan wrote:
> Bob,
>
> It seems to me that your question "can you get off shorter runways,
> fly over taller mountains, endure longer with a failed alternator, or
> carry more baggage?" adds little to the discussion. I say this because
> making an airplane light is accomplished by many decisions to save
> small amounts of weight by going with option B rather than option A,
> option D rather than option C, etc. The cumulative result of all of
> these decisions does indeed allow one to get off quicker, climb
> faster, carry more baggage, etc. However, if we were to evaluate each
> decision individually, as you seek to do with lithium batteries,
> probably none of them achieve a meaningful difference in aircraft
> performance.
>
> The question to ask is not what the effect will be on aircraft
> performance. We already know that. This is no mystery. The question is
> already answered, because every pound counts just as much as every
> other pound when it comes to weight related performance whether it be
> a lighter battery, the choice of titanium over stainless steel for the
> firewall, or the decision to go on a diet to achieve a smaller beer
> belly. It seems to me the important questions are "How does the cost
> of lithium compare to the cost of lead acid?" and "How does the safety
> of lithium compare to the safety of lead acid?" Those questions are
> important. Questions of weight related aircraft performance are merely
> rhetorical.
>
> On Sun, Nov 2, 2014 at 2:11 PM, Robert L. Nuckolls, III
> <nuckolls.bob@aeroelectric.com <mailto:nuckolls.bob@aeroelectric.com>>
> wrote:
>
> At 15:55 2014-11-02, you wrote:
> Hi Bob;
>
> I have heard, but have no personal experience, that the danger of
> fires from lithium iron batteries is much reduced in comparison to
> lithium ion batteries, while their weight is only slightly greater.
>
> To be sure, there are big differences in how the various
> chemistries behave AFTER the fire starts . . . but all
> battery chemistries from lead-acid to ni-cad, to lithium
> store a lot of energy in a relatively small volume. So
> all chemistries present some hazard for rapid release of that
> energy to varying degrees. Even the out-gassing products
> of Li-Iron are combustible. This is why the True Blue batteries
>
> [] * . . .
> have those little 'smoke stacks' on top. They connect to a
> vent tube designed to take the nasties over-board in the event
> of catastrophic failure within a case DESIGNED to contain
> such events.
>
> To test the integrity of the case, the protective features
> of the battery management system (BMS) are disabled and
> the test lab puts 42 volts to the array of cells. After
> a period of time, a 'fog' of nasties begins to pour from
> the vent but case temperatures remain quite nominal . . .
> non-hazardous to children and other living things aboard
> the airplane.
>
> The design philosophy calls for getting this electronic version
> of nitro-glycerine packaged in a manner that contains
> worst-case failures . . . Damn I love FMEAs! Fooey on that
> reliability study stuff . . . assume the worst and tame it.
>
> *So one of my questions is: With which type of battery are you
> experimenting? If it's not lithium iron, I suggest you get one of
> those too.
>
> These are lithium-iron . . .
>
> http://tinyurl.com/m4mlvsq
>
> <http://tinyurl.com/m4mlvsq>but for the purposes of my articles,
> it doesn't matter. If
> the cells being offered by the various vendors take FMEA
> into account and drive risks to acceptably low levels,
> we have to assume that the energies contained are (1)
> only allowed to get out through the terminals as electron
> flow or (2) are very low risk due to management of manufacturing
> quality and/or some manner of de-rating . . . like operating
> them in the lower half of their energy storage tank?
>
> My second point is: Could a simple solid state DC voltage
> regulator be designed to bring the 16.8 V. down to 14.4 V? This
> would maximize the potential of the lithium battery.
>
> This is exactly what the makers of computers, tablets,
> cell phones, and other products do. They use chargers
> designed for the battery voltage selected . . . and discharge
> to switch-mode power supplies that offers the desired system
> voltage. Unfortunately, our 'charger' is that belt driven
> thingy up front that is not especially tailored to the
> care and feeding of lithium. Even if it were, then yes, we'd
> need some mater of dc/dc converter to re-flavor the volts
> to 14.4.
>
> The thrust of my articles is to explore the cost/benefit
> ratio for 'going lithium'. After you've spent the dollars
> for the premium product, can you get off shorter runways,
> fly over taller mountains, endure longer with a failed
> alternator, or carry more baggage?
>
> The design decisions are sort like those we should have
> considered when we put those headers and 4-bbl carburetors on
> our school transportation car . . . when we were so strapped
> for cash that the used tire store was more likely to get
> our business than Firestone. Good decision making is called
> spontaneous organization, the science of elegant trade-offs.
>
>
> I have read the AeroElectric Connection through a second time and
> really appreciate the work you do.
> Cheers!
>
> Thank you for that endorsement. I'm pleased that you find
> the work useful.
>
> Bob . . .
>
>
Message 6
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Subject: | Re: Radio Transmits Poorly Only When On The Ground |
I had a somewhat similar issue with that radio. At the time I had an
assortment of headsets with different but not definitive results.
Opening the case and reducing the mic gain helped but a slightly
different setting seemed optimum for each headset . Eventually I noticed
that the problem was worse in the morning and typically went away after
10 or 15 minutes by which time I was usually airborne. When I asked
David Clark whether this might have anything to do with my mic they said
yes it could and they offered to replace it which did indeed fix the
issue for me. I bought a second DC headset and have been happy ever since.
Ken
On 03/11/2014 2:45 PM, Charlie England wrote:
> <ceengland7@gmail.com>
>
> On 11/3/2014 6:06 AM, DaveG601XL wrote:
>> <david.m.gallagher@ge.com>
>>
>> I have a gremlin that I don't know how to troubleshoot. I have a
>> 601XL all-metal airplane with an Icom A-200 radio, a RAMI com antenna
>> mounted on the top skin and connected with RG-400 cable. I did all
>> the installation myself. I have had this flying for 6 years now. It
>> transmits just fine in the air, but when I initially installed it, I
>> would get comments that it was a bit garbled while transmitting on
>> the ground. It was always good enough though, as I could still carry
>> on a 2-way conversation, plus I was able to operate out of tower
>> controlled airports and not get any negative radio comments.
>> Receiving wise, I have always been able to hear just fine whether on
>> the ground or in the air.
>>
>> Just this summer, I started to get comments from fellow pilots that I
>> was totally unreadable while transmitting on the ground. It would
>> become crystal clear as soon as I took off. Does anyone have any
>> thoughts of why this could be occurring or any place in particular I
>> should start my troubleshooting??
>>
>> Thanks,
>>
>> --------
>> David Gallagher
>> Zodiac 601 XL-B: flying, 280+ hours now
>> Next project under construction: Finish my father's Aircamper
>>
>>
> Everybody, or just some other pilots? I have a similar issue with my
> MicroAir when in receive mode and flying within a few hundred feet of
> another a/c. I'm pretty sure that the AGC (automatic gain control) in
> the MicroAir doesn't have enough range to avoid overdriving its input
> when the transmitting a/c is close. Other radios don't have this
> problem in the same environment.
>
> Charlie
>
> _
Message 7
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Subject: | Re: lithium facts |
At 19:15 2014-11-02, you wrote:
>Yes, I should have included that. Also I should have included "How
>does Li compare to Pb with respect to cranking the engine?"
There is no reason for any builder to believe that
lithium products are not suited for cranking their
engine -OR- running all desired electro-whizzies
for a duration that meets design goals.
Further, if you have an AGM battery installed that
already meets your performance goals, then a lithium
replacement for that battery will probably be lighter
and occupy less volume.
If your missions are day-vfr only and you have
no battery only endurance requirements, then
you're on pretty solid ground to accept the marketer's
"lead acid equivalency" or "drop in replacement"
assertions at face value. Further, your purchase
will be MUCH lighter and smaller.
I'm presently in possession of one of these
products:
http://tinyurl.com/jwk9wcu
Note that the ad says this is a 'drop in' replacement
for the Yuasa YTX20 series batteries (18 ah at a
10 hour rate), the YTX24 series (21 a.h.) and the
UB12350 (35 a.h.). This statement should raise some
eyebrows. The ETX36 may indeed CRANK like all of these
batteries it purports to replace.
Here's part of the data I've collected off this sample
thus far:
Emacs!
When loaded to 5Amps, this battery consistently delivers about
140 watt-hours of stored energy for a 2-hour rate of 11.5
ampere-hours. We also see that this battery's charge cycle
is pretty well ended at 12 volts, one full volt higher than
end of charge on an SLVA battery.
Incidentally, the family of curves cited above shows that
out of the box, charged at 13.0 volts, 14.0 volts, and 15.0
volts, the device dumps a consistent energy value. This speaks
well of the battery's internal battery management system.
So how would this battery stack up for battery-only operations
when replacing any one of the devices for which it is sold as
a drop-in replacement?
These data suggest that if your application calls for a KNOWN
level of stored energy the ETX is NOT a drop in replacement
for the products listed . Assuming that this battery, or one of
its cousins, meets your cranking and stored energy requirements,
then how does it stack up for a weight reduction goal at $350
a pop?
Bob . . .
Message 8
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Subject: | Re: Radio Transmits Poorly Only When On The Ground |
At 06:06 2014-11-03, you wrote:
><david.m.gallagher@ge.com>
>
>I have a gremlin that I don't know how to troubleshoot. I have a
>601XL all-metal airplane with an Icom A-200 radio, a RAMI com
>antenna mounted on the top skin and connected with RG-400 cable. I
>did all the installation myself. I have had this flying for 6 years
>now. It transmits just fine in the air, but when I initially
>installed it, I would get comments that it was a bit garbled while
>transmitting on the ground. It was always good enough though, as I
>could still carry on a 2-way conversation, plus I was able to
>operate out of tower controlled airports and not get any negative
>radio comments. Receiving wise, I have always been able to hear just
>fine whether on the ground or in the air.
>
>Just this summer, I started to get comments from fellow pilots that
>I was totally unreadable while transmitting on the ground. It would
>become crystal clear as soon as I took off. Does anyone have any
>thoughts of why this could be occurring or any place in particular I
>should start my troubleshooting??
>
>Thanks,
What tests have you run? Have you tried a different
microphone? Does your system include an intercom
or does the mic connect directly to the radio?
Bob . . .
Message 9
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Subject: | Re: lithium facts |
Hi Bob;
Thank you for performing a valuable service in testing lithium iron
batteries. You have made a good point that a lithium iron battery may be
capable of starting the engine, but may fall short in longevity while
running the instruments. One point that has not been made in their favor
is that substitution of a 3 to 4# battery for a 20 to 30# one may solve a
weight and balance problem without needing to move the battery to the tail
cone and adding long and heavy cables.
Cheers! Stu.
On Mon, Nov 3, 2014 at 5:28 PM, Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> At 19:15 2014-11-02, you wrote:
>
> Yes, I should have included that. Also I should have included "How does Li
> compare to Pb with respect to cranking the engine?"
>
>
> There is no reason for any builder to believe that
> lithium products are not suited for cranking their
> engine -OR- running all desired electro-whizzies
> for a duration that meets design goals.
>
> Further, if you have an AGM battery installed that
> already meets your performance goals, then a lithium
> replacement for that battery will probably be lighter
> and occupy less volume.
>
> If your missions are day-vfr only and you have
> no battery only endurance requirements, then
> you're on pretty solid ground to accept the marketer's
> "lead acid equivalency" or "drop in replacement"
> assertions at face value. Further, your purchase
> will be MUCH lighter and smaller.
>
> I'm presently in possession of one of these
> products:
>
> http://tinyurl.com/jwk9wcu
>
> Note that the ad says this is a 'drop in' replacement
> for the Yuasa YTX20 series batteries (18 ah at a
> 10 hour rate), the YTX24 series (21 a.h.) and the
> UB12350 (35 a.h.). This statement should raise some
> eyebrows. The ETX36 may indeed CRANK like all of these
> batteries it purports to replace.
>
> Here's part of the data I've collected off this sample
> thus far:
>
> [image: Emacs!]
>
> When loaded to 5Amps, this battery consistently delivers about
> 140 watt-hours of stored energy for a 2-hour rate of 11.5
> ampere-hours. We also see that this battery's charge cycle
> is pretty well ended at 12 volts, one full volt higher than
> end of charge on an SLVA battery.
>
> Incidentally, the family of curves cited above shows that
> out of the box, charged at 13.0 volts, 14.0 volts, and 15.0
> volts, the device dumps a consistent energy value. This speaks
> well of the battery's internal battery management system.
>
> So how would this battery stack up for battery-only operations
> when replacing any one of the devices for which it is sold as
> a drop-in replacement?
>
> These data suggest that if your application calls for a KNOWN
> level of stored energy the ETX is NOT a drop in replacement
> for the products listed . Assuming that this battery, or one of
> its cousins, meets your cranking and stored energy requirements,
> then how does it stack up for a weight reduction goal at $350
> a pop?
>
> Bob . . .
>
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