Today's Message Index:
----------------------
1. 08:04 AM - Earthx LiFePO4 for aircraft (Jan de Jong)
2. 11:04 AM - Re: Earthx LiFePO4 for aircraft (Charlie England)
3. 12:16 PM - Re: Earthx LiFePO4 for aircraft (Jan de Jong)
4. 07:47 PM - Re: Earthx LiFePO4 for aircraft (Robert L. Nuckolls, III)
Message 1
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| Subject: | Earthx LiFePO4 for aircraft |
Just in case I am not the only one to have missed this...
Earthx appears to have responded to complaints from aircraftbuilders:
http://earthxmotorsports.com/wp-content/uploads/2015/07/ETX_Manual_111017_K.pdf
see "Hundred Series" - the battery holds up when the alternator is shut off.
Jan de Jong
Message 2
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| Subject: | Re: Earthx LiFePO4 for aircraft |
On 10/27/2015 10:02 AM, Jan de Jong wrote:
> <jan_de_jong@casema.nl>
>
> Just in case I am not the only one to have missed this...
>
> Earthx appears to have responded to complaints from aircraftbuilders:
>
> http://earthxmotorsports.com/wp-content/uploads/2015/07/ETX_Manual_111017_K.pdf
>
> see "Hundred Series" - the battery holds up when the alternator is
> shut off.
>
> Jan de Jong
While it's likely a viable option for a/c use, their PR people and now,
their tech writers, really give me pause.
quote from your link:
In a lead-acid battery the cells are package in the same case with an
acid solution that supports the transfer of charge from higher voltage
cells to ones with a lower voltage.
unquote.
Say What?
I've never seen a lead acid battery that shared acid between cells.
I also think that they are highly deceptive in claiming that a 6 AH lead
acid battery is really only 2 AH. If it were, it would be rated at 2 AH.
That 30% number they keep citing is the discharge level for maximum life
of the battery; not how much energy can be extracted from it. In a
normal environment, the battery would never be discharged below ~90%,
and that would be due to a really extended engine start event. In a
straight discharge (dead alternator) situation, 6 AH is 6 AH, and 2 AH
is 2 AH.
Charlie
Message 3
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| Subject: | Re: Earthx LiFePO4 for aircraft |
I believe it was Shorai who introduced the "PbEq" Ah rating and the
factor of 3.
So there is some defensive and also some wrong PR in the introductory
part of the text.
At least in their specifications they quote the actual Ah number in
addition to the "PbEq".
And they show discharge curves for currents and temperatures.
Now they also have, in principle, a correct aircraft battery.
I strongly suspect they have a very capable electronics engineer there.
But experience will tell.
Jan de Jong
On 10/27/2015 7:00 PM, Charlie England wrote:
> <ceengland7@gmail.com>
>
> On 10/27/2015 10:02 AM, Jan de Jong wrote:
>> <jan_de_jong@casema.nl>
>>
>> Just in case I am not the only one to have missed this...
>>
>> Earthx appears to have responded to complaints from aircraftbuilders:
>>
>> http://earthxmotorsports.com/wp-content/uploads/2015/07/ETX_Manual_111017_K.pdf
>>
>> see "Hundred Series" - the battery holds up when the alternator is
>> shut off.
>>
>> Jan de Jong
> While it's likely a viable option for a/c use, their PR people and
> now, their tech writers, really give me pause.
> quote from your link:
> In a lead-acid battery the cells are package in the same case with an
> acid solution that supports the transfer of charge from higher voltage
> cells to ones with a lower voltage.
> unquote.
>
> Say What?
>
> I've never seen a lead acid battery that shared acid between cells.
>
> I also think that they are highly deceptive in claiming that a 6 AH
> lead acid battery is really only 2 AH. If it were, it would be rated
> at 2 AH. That 30% number they keep citing is the discharge level for
> maximum life of the battery; not how much energy can be extracted from
> it. In a normal environment, the battery would never be discharged
> below ~90%, and that would be due to a really extended engine start
> event. In a straight discharge (dead alternator) situation, 6 AH is 6
> AH, and 2 AH is 2 AH.
>
> Charlie
>
>
Message 4
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| Subject: | Re: Earthx LiFePO4 for aircraft |
>
>
>Say What?
>
>I've never seen a lead acid battery that shared acid between cells.
>
>I also think that they are highly deceptive in claiming that a 6 AH
>lead acid battery is really only 2 AH. If it were, it would be rated
>at 2 AH. That 30% number they keep citing is the discharge level for
>maximum life of the battery; not how much energy can be extracted
>from it. In a normal environment, the battery would never be
>discharged below ~90%, and that would be due to a really extended
>engine start event. In a straight discharge (dead alternator)
>situation, 6 AH is 6 AH, and 2 AH is 2 AH.
>
>Charlie
I've had a couple of 'semantics wrestling' matches
with EarthX. This whole 'lead-acid equivalency' thing
is smoke and mirrors . . . at least as far as
aircraft are concerned . . . where STARTING an engine
is NOT the defining factor for battery sizing.
They asked me to participate in the development of
an EarthX 'application' document wherein the company
would suggest one of their products as suited for
popular models of aircraft. I attempt to explain that
such a document was not only fraught with potential
for error, it opened them up for a lawsuit should some
hapless pilot run out of battery snort after having
replaced the stock SVLA battery based on EarthX lead-acid
equivalency claims.
I have an EarthX battery sample that I intend to test
on my minivan. But I need a data acquisition system
that Paul and I have under development. It will
gather fine resolution data for battery performance
for long periods of time. I'll get a month of data
on the as-installed, soggy battery. Then on the EarthX
battery, then on a new battery of the size recommended
for the car. I'll do cap-checks on all three test
articles as well.
But in any case, be aware of the need for knowing
USEABLE CAPACITY of any battery you install irrespective
of brand or chemistry. Understand further that many
of the folks out there hawking light weight super-batteries
to the OBAM aviation DO NOT appear to understand
the unique requirements for integrating a battery onto
an airplane.
Bob . . .
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