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Discussion Starter · #1 ·
I talked to Wayne on the phone today; he wanted some input on what he
could tell some of his customers about ranges and energy consumption.
Wayne apparently has done several 144v (45 cell) LFP conversions.

I offer the following details that I was not able to give Wayne on the
phone.

I have just under 15K miles and have averaged about 2ah/mile (288wh/m).
Many trips have given me 1.85-1.9 ah/mile. One test of about 30 miles
gave me about 1.6ah/m @ about 30 mph. Typical speeds are 40-60 mph
with minor amounts of time both below 40 and above 60.

Two tests on my nominal 260ah pack capacity gave me 300ah one time and
280ah the other.

I claim a 120 mile range, but that has a significant safety margin. I
wouldn't be at all surprised to be able to go 150 miles.

A couple of recent modifications:
1) I replaced the 75W-80 transaxle oil with Royal Purple 5W-30
"racing" oil at the recommendation of the Royal Purple people. Energy
use for the first 10+ miles of trips in cool weather would be 2.1-2.2
ah/m. With the new oil, that "warming up" penalty seems to have
disappeared.
2) I replaced the 14" OEM tires with P195/65R-15 Goodyear Assurance
Fuel Max. These are about 6.5% larger than the OEM tires. The reason
for going to larger tires was to increase load capacity.

The combination of mods continues to give me about 2ah/m, but with 6.5%
longer miles. So, I believe the above numbers can now be adjusted to
~1.88 ah/m average and going as low as about 1.74 ah/m for "normal"
speeds. So I might be able to go 144 miles on 250ah and about 170
miles on 300ah. I wish I had time and a location to try to go 200
miles @ 30 mph.

I got the impression that Wayne may not be putting amp-hour counters on
all his conversions. He did put a TBS on mine. Amp-hour counting is
crucial to combating range anxiety. I really can't imagine using my EV
(or measuring pack capacity) without the TBS; I constantly mentally
figure energy use from the odometer and TBS readings. Wayne opined that
ah counting may become an internal software upgrade to NetGain
controllers. Thinking about that, I don't see how the charging ah could
be recorded.

http://evalbum.com/2314
--
Willie, ONWARD! Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime 80 days 16 hours 04 minutes

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Discussion Starter · #2 ·
I don't understand how amp-hrs can give you useful data if you don't specify
voltage as well. Isn't watt-hrs/mile the goal you are after? Or do you
assume some constant voltage? Thanks for any clarification.

But you numbers for a conversion (as opposed to an EV built from scratch )
look very good to me.

-- Larry Gales

Willie McKemie <[email protected]> wrote:

> I talked to Wayne on the phone today; he wanted some input on what he
> could tell some of his customers about ranges and energy consumption.
> Wayne apparently has done several 144v (45 cell) LFP conversions.
>
> I offer the following details that I was not able to give Wayne on the
> phone.
>
> I have just under 15K miles and have averaged about 2ah/mile (288wh/m).
> Many trips have given me 1.85-1.9 ah/mile. One test of about 30 miles
> gave me about 1.6ah/m @ about 30 mph. Typical speeds are 40-60 mph
> with minor amounts of time both below 40 and above 60.
>
> Two tests on my nominal 260ah pack capacity gave me 300ah one time and
> 280ah the other.
>
> I claim a 120 mile range, but that has a significant safety margin. I
> wouldn't be at all surprised to be able to go 150 miles.
>
> A couple of recent modifications:
> 1) I replaced the 75W-80 transaxle oil with Royal Purple 5W-30
> "racing" oil at the recommendation of the Royal Purple people. Energy
> use for the first 10+ miles of trips in cool weather would be 2.1-2.2
> ah/m. With the new oil, that "warming up" penalty seems to have
> disappeared.
> 2) I replaced the 14" OEM tires with P195/65R-15 Goodyear Assurance
> Fuel Max. These are about 6.5% larger than the OEM tires. The reason
> for going to larger tires was to increase load capacity.
>
> The combination of mods continues to give me about 2ah/m, but with 6.5%
> longer miles. So, I believe the above numbers can now be adjusted to
> ~1.88 ah/m average and going as low as about 1.74 ah/m for "normal"
> speeds. So I might be able to go 144 miles on 250ah and about 170
> miles on 300ah. I wish I had time and a location to try to go 200
> miles @ 30 mph.
>
> I got the impression that Wayne may not be putting amp-hour counters on
> all his conversions. He did put a TBS on mine. Amp-hour counting is
> crucial to combating range anxiety. I really can't imagine using my EV
> (or measuring pack capacity) without the TBS; I constantly mentally
> figure energy use from the odometer and TBS readings. Wayne opined that
> ah counting may become an internal software upgrade to NetGain
> controllers. Thinking about that, I don't see how the charging ah could
> be recorded.
>
> http://evalbum.com/2314
> --
> Willie, ONWARD! Through the fog!
> http://counter.li.org Linux registered user #228836 since 1995
> Debian3.1/GNU/Linux system uptime 80 days 16 hours 04 minutes
>
> _______________________________________________
> | REPLYING: address your message to [email protected] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>



--
Larry Gales
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Discussion Starter · #3 ·
Hi Larry,

>I don't understand how amp-hrs can give you useful data if you don't
>specify
> voltage as well. Isn't watt-hrs/mile the goal you are after?

When you use an e-meter as a fuel guage, tracking Ah used gives a more
linear approximation to remaining range than tracking Wh used.

That usually means you know off the top of your head how many Ah/mile your
vehicle uses, but not how many Wh/mile.

Thats certainly what I have found.

Matt

----- Original Message -----
From: "Larry Gales" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Thursday, December 02, 2010 11:34 AM
Subject: Re: [EVDL] mileage


>I don't understand how amp-hrs can give you useful data if you don't
>specify
> voltage as well. Isn't watt-hrs/mile the goal you are after? Or do you
> assume some constant voltage? Thanks for any clarification.
>
> But you numbers for a conversion (as opposed to an EV built from scratch )
> look very good to me.
>
> -- Larry Gales
>
> On Wed, Dec 1, 2010 at 5:45 PM, Willie McKemie <[email protected]>
> wrote:
>
>> I talked to Wayne on the phone today; he wanted some input on what he
>> could tell some of his customers about ranges and energy consumption.
>> Wayne apparently has done several 144v (45 cell) LFP conversions.
>>
>> I offer the following details that I was not able to give Wayne on the
>> phone.
>>
>> I have just under 15K miles and have averaged about 2ah/mile (288wh/m).
>> Many trips have given me 1.85-1.9 ah/mile. One test of about 30 miles
>> gave me about 1.6ah/m @ about 30 mph. Typical speeds are 40-60 mph
>> with minor amounts of time both below 40 and above 60.
>>
>> Two tests on my nominal 260ah pack capacity gave me 300ah one time and
>> 280ah the other.
>>
>> I claim a 120 mile range, but that has a significant safety margin. I
>> wouldn't be at all surprised to be able to go 150 miles.
>>
>> A couple of recent modifications:
>> 1) I replaced the 75W-80 transaxle oil with Royal Purple 5W-30
>> "racing" oil at the recommendation of the Royal Purple people. Energy
>> use for the first 10+ miles of trips in cool weather would be 2.1-2.2
>> ah/m. With the new oil, that "warming up" penalty seems to have
>> disappeared.
>> 2) I replaced the 14" OEM tires with P195/65R-15 Goodyear Assurance
>> Fuel Max. These are about 6.5% larger than the OEM tires. The reason
>> for going to larger tires was to increase load capacity.
>>
>> The combination of mods continues to give me about 2ah/m, but with 6.5%
>> longer miles. So, I believe the above numbers can now be adjusted to
>> ~1.88 ah/m average and going as low as about 1.74 ah/m for "normal"
>> speeds. So I might be able to go 144 miles on 250ah and about 170
>> miles on 300ah. I wish I had time and a location to try to go 200
>> miles @ 30 mph.
>>
>> I got the impression that Wayne may not be putting amp-hour counters on
>> all his conversions. He did put a TBS on mine. Amp-hour counting is
>> crucial to combating range anxiety. I really can't imagine using my EV
>> (or measuring pack capacity) without the TBS; I constantly mentally
>> figure energy use from the odometer and TBS readings. Wayne opined that
>> ah counting may become an internal software upgrade to NetGain
>> controllers. Thinking about that, I don't see how the charging ah could
>> be recorded.
>>
>> http://evalbum.com/2314
>> --
>> Willie, ONWARD! Through the fog!
>> http://counter.li.org Linux registered user #228836 since 1995
>> Debian3.1/GNU/Linux system uptime 80 days 16 hours 04 minutes
>>
>> _______________________________________________
>> | REPLYING: address your message to [email protected] only.
>> | Multiple-address or CCed messages may be rejected.
>> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
>> | OTHER HELP: http://evdl.org/help/
>> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>>
>
>
>
> --
> Larry Gales
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Discussion Starter · #4 ·
Larry Gales <[email protected]> wrote:
> I don't understand how amp-hrs can give you useful data if you don't spec=
ify
> voltage as well. Isn't watt-hrs/mile the goal you are after? Or do =
you
> assume some constant voltage? Thanks for any clarification.

Wh/mile gives a better comparison from one car to another, but Ah is
more useful for estimating how much range you have left.

Variations of temperature, driving style, and driving conditions will
have less effect on Ah than on Wh.

So it makes sense that Willie would monitor and keep track of Ah/mile,
and he'd give us the data that he knows best.

-Morgan LaMoore

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Discussion Starter · #5 ·
Larry Gales <[email protected]> wrote:
> I don't understand how amp-hrs can give you useful data if you don't spec=
ify
> voltage as well. Isn't watt-hrs/mile the goal you are after? Or do =
you
> assume some constant voltage? Thanks for any clarification.

In addition to the other replies it is important to note the discharge
curve for the LiFePO4 batteries. Take a look at this graph:
http://ebikes.ca/images/B3608LiF-EZ_Graph.gif. Note that the voltage
is very flat during the majority of the discharge curve. Since it is
very flat, the Ah usage compared to the Wh usage doesn't change for
the majority of the discharge. You can also see it in the two graphs
posted here: http://jackrickard.blogspot.com/2009/12/ok-here-it-is-sag-volt=
age-more.html.
I think that if another type of battery such as LiPoly
(http://ebikes.ca/images/B3610LiP-EZ_Graph.gif) or a lead acid battery
the correlation between Ah/mile and Wh/mile would vary quite a bit
through out the discharge curve because of the large change in voltage
and other factors.

-- =

David D. Nelson
http://evalbum.com/1328

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Discussion Starter · #6 ·
OK, thanks for the insight.

-- Larry Gales

matt lacey <[email protected]> wrote:

>
> Hi Larry,
>
> >I don't understand how amp-hrs can give you useful data if you don't
> >specify
> > voltage as well. Isn't watt-hrs/mile the goal you are after?
>
> When you use an e-meter as a fuel guage, tracking Ah used gives a more
> linear approximation to remaining range than tracking Wh used.
>
> That usually means you know off the top of your head how many Ah/mile your
> vehicle uses, but not how many Wh/mile.
>
> Thats certainly what I have found.
>
> Matt
>
> ----- Original Message -----
> From: "Larry Gales" <[email protected]>
> To: "Electric Vehicle Discussion List" <[email protected]>
> Sent: Thursday, December 02, 2010 11:34 AM
> Subject: Re: [EVDL] mileage
>
>
> >I don't understand how amp-hrs can give you useful data if you don't
> >specify
> > voltage as well. Isn't watt-hrs/mile the goal you are after? Or do you
> > assume some constant voltage? Thanks for any clarification.
> >
> > But you numbers for a conversion (as opposed to an EV built from scratch
> )
> > look very good to me.
> >
> > -- Larry Gales
> >
> > On Wed, Dec 1, 2010 at 5:45 PM, Willie McKemie <[email protected]>
> > wrote:
> >
> >> I talked to Wayne on the phone today; he wanted some input on what he
> >> could tell some of his customers about ranges and energy consumption.
> >> Wayne apparently has done several 144v (45 cell) LFP conversions.
> >>
> >> I offer the following details that I was not able to give Wayne on the
> >> phone.
> >>
> >> I have just under 15K miles and have averaged about 2ah/mile (288wh/m).
> >> Many trips have given me 1.85-1.9 ah/mile. One test of about 30 miles
> >> gave me about 1.6ah/m @ about 30 mph. Typical speeds are 40-60 mph
> >> with minor amounts of time both below 40 and above 60.
> >>
> >> Two tests on my nominal 260ah pack capacity gave me 300ah one time and
> >> 280ah the other.
> >>
> >> I claim a 120 mile range, but that has a significant safety margin. I
> >> wouldn't be at all surprised to be able to go 150 miles.
> >>
> >> A couple of recent modifications:
> >> 1) I replaced the 75W-80 transaxle oil with Royal Purple 5W-30
> >> "racing" oil at the recommendation of the Royal Purple people. Energy
> >> use for the first 10+ miles of trips in cool weather would be 2.1-2.2
> >> ah/m. With the new oil, that "warming up" penalty seems to have
> >> disappeared.
> >> 2) I replaced the 14" OEM tires with P195/65R-15 Goodyear Assurance
> >> Fuel Max. These are about 6.5% larger than the OEM tires. The reason
> >> for going to larger tires was to increase load capacity.
> >>
> >> The combination of mods continues to give me about 2ah/m, but with 6.5%
> >> longer miles. So, I believe the above numbers can now be adjusted to
> >> ~1.88 ah/m average and going as low as about 1.74 ah/m for "normal"
> >> speeds. So I might be able to go 144 miles on 250ah and about 170
> >> miles on 300ah. I wish I had time and a location to try to go 200
> >> miles @ 30 mph.
> >>
> >> I got the impression that Wayne may not be putting amp-hour counters on
> >> all his conversions. He did put a TBS on mine. Amp-hour counting is
> >> crucial to combating range anxiety. I really can't imagine using my EV
> >> (or measuring pack capacity) without the TBS; I constantly mentally
> >> figure energy use from the odometer and TBS readings. Wayne opined that
> >> ah counting may become an internal software upgrade to NetGain
> >> controllers. Thinking about that, I don't see how the charging ah could
> >> be recorded.
> >>
> >> http://evalbum.com/2314
> >> --
> >> Willie, ONWARD! Through the fog!
> >> http://counter.li.org Linux registered user #228836 since 1995
> >> Debian3.1/GNU/Linux system uptime 80 days 16 hours 04 minutes
> >>
> >> _______________________________________________
> >> | REPLYING: address your message to [email protected] only.
> >> | Multiple-address or CCed messages may be rejected.
> >> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> >> | OTHER HELP: http://evdl.org/help/
> >> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
> >>
> >
> >
> >
> > --
> > Larry Gales
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>
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>
>
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--
Larry Gales
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Discussion Starter · #7 ·
120 miles? Pretty impressive!

I claim a 120 mile range, but that has a significant safety margin.
--> Which one is that safety margin?



-------- Original-Nachricht --------
> Datum: Wed, 1 Dec 2010 19:45:28 -0600
> Von: Willie McKemie <[email protected]>
> An: Electric Vehicle Discussion List <[email protected]>
> Betreff: [EVDL] mileage

> I talked to Wayne on the phone today; he wanted some input on what he
> could tell some of his customers about ranges and energy consumption.
> Wayne apparently has done several 144v (45 cell) LFP conversions.
>
> I offer the following details that I was not able to give Wayne on the
> phone.
>
> I have just under 15K miles and have averaged about 2ah/mile (288wh/m).
> Many trips have given me 1.85-1.9 ah/mile. One test of about 30 miles
> gave me about 1.6ah/m @ about 30 mph. Typical speeds are 40-60 mph
> with minor amounts of time both below 40 and above 60.
>
> Two tests on my nominal 260ah pack capacity gave me 300ah one time and
> 280ah the other.
>
> I claim a 120 mile range, but that has a significant safety margin. I
> wouldn't be at all surprised to be able to go 150 miles.
>
> A couple of recent modifications:
> 1) I replaced the 75W-80 transaxle oil with Royal Purple 5W-30
> "racing" oil at the recommendation of the Royal Purple people. Energy
> use for the first 10+ miles of trips in cool weather would be 2.1-2.2
> ah/m. With the new oil, that "warming up" penalty seems to have
> disappeared.
> 2) I replaced the 14" OEM tires with P195/65R-15 Goodyear Assurance
> Fuel Max. These are about 6.5% larger than the OEM tires. The reason
> for going to larger tires was to increase load capacity.
>
> The combination of mods continues to give me about 2ah/m, but with 6.5%
> longer miles. So, I believe the above numbers can now be adjusted to
> ~1.88 ah/m average and going as low as about 1.74 ah/m for "normal"
> speeds. So I might be able to go 144 miles on 250ah and about 170
> miles on 300ah. I wish I had time and a location to try to go 200
> miles @ 30 mph.
>
> I got the impression that Wayne may not be putting amp-hour counters on
> all his conversions. He did put a TBS on mine. Amp-hour counting is
> crucial to combating range anxiety. I really can't imagine using my EV
> (or measuring pack capacity) without the TBS; I constantly mentally
> figure energy use from the odometer and TBS readings. Wayne opined that
> ah counting may become an internal software upgrade to NetGain
> controllers. Thinking about that, I don't see how the charging ah could
> be recorded.
>
> http://evalbum.com/2314
> --
> Willie, ONWARD! Through the fog!
> http://counter.li.org Linux registered user #228836 since 1995
> Debian3.1/GNU/Linux system uptime 80 days 16 hours 04 minutes
>
> _______________________________________________
> | REPLYING: address your message to [email protected] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev

--
GMX DSL Doppel-Flat ab 19,99 €/mtl.! Jetzt auch mit
gratis Notebook-Flat! http://portal.gmx.net/de/go/dsl

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Discussion Starter · #8 ·
On Thu, Dec 02, 2010 at 11:45:00AM +0800, matt lacey wrote:
>
> Hi Larry,
>
> >I don't understand how amp-hrs can give you useful data if you don't
> >specify
> > voltage as well. Isn't watt-hrs/mile the goal you are after?
>
> When you use an e-meter as a fuel guage, tracking Ah used gives a more
> linear approximation to remaining range than tracking Wh used.

I don't closely monitor pack voltage; the TBS displays only one
parameter at a time and I mostly monitor ah.

I charge my 45 LFP cells to 160-165 v. It can go up to about 170 v
without tripping the high individual cell charger cut-off if I use my
"balancing charger" to get all cell modules by-passing ~1/2 amp. BTW,
I am now using a mixture of EVPower and miniBMS cell modules.

At the start of a trip, after a full charge, the pack voltage is around
150 and it quickly declines to 144 to maybe 146 under light loads.
With typical trips, the "light load" voltage rarely goes below about
137. When/if I get down in the SOC range of 10-20%, the pack voltage
gets down close to 130. All numbers subject to "recollection errors".

So, indeed, 144v is a good average number to use in converting ah to
wh.

Here is an un-explained oddity. For conditions of constant energy
usage, I would expect to see ah/m increase as voltage declines. I see
just the opposite. Most of my trips see 1.9-2.0 ah/m after a warm up
period. But, near the end of the trip with a voltage decline to around
140, 1.7-1.8 is a likely measurement,

--
Willie, ONWARD! Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime 81 days 2 hours 57 minutes

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Discussion Starter · #9 ·
Willie McKemie <[email protected]> wrote:
> Here is an un-explained oddity. For conditions of constant energy
> usage, I would expect to see ah/m increase as voltage declines. I see
> just the opposite. Most of my trips see 1.9-2.0 ah/m after a warm up
> period. But, near the end of the trip with a voltage decline to around
> 140, 1.7-1.8 is a likely measurement,

Do you have a way to monitor battery temperature? I know my cells warm
up after a sustained 0.5C pull on them. Maybe they are warming up and
increasing in efficiency.

-- =

David D. Nelson
http://evalbum.com/1328

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Discussion Starter · #10 ·
David Nelson wrote:
> On Thu, Dec 2, 2010 at 4:20 AM, Willie McKemie <[email protected]> wrot=
e:
> > Here is an un-explained oddity. For conditions of constant energy
> > usage, I would expect to see ah/m increase as voltage declines. I see
> > just the opposite. Most of my trips see 1.9-2.0 ah/m after a warm up
> > period. But, near the end of the trip with a voltage decline to arou=
nd
> > 140, 1.7-1.8 is a likely measurement,
> =

> Do you have a way to monitor battery temperature? I know my cells warm
> up after a sustained 0.5C pull on them. Maybe they are warming up and
> increasing in efficiency.

Good thought! I have one of those remote sensing (infrared?) =

thermometers that I bought to look for hot terminals. Next trip, I'll =

check cell temperatures before and after. Though I've never noticed =

cells being the least bit warm. My average draw is around 1/3C.

-- =

Willie, ONWARD! Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime 82 days 4 hours 09 minutes

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Discussion Starter · #11 ·
Another possibility is that the whole drive train has warmed up
decreasing it's drag.

Willie McKemie <[email protected]> wrote:
> On Thu, Dec 02, 2010 at 08:29:06PM -0800, David Nelson wrote:
>> On Thu, Dec 2, 2010 at 4:20 AM, Willie McKemie <[email protected]> wro=
te:
>> > Here is an un-explained oddity. For conditions of constant energy
>> > usage, I would expect to see ah/m increase as voltage declines. I s=
ee
>> > just the opposite. Most of my trips see 1.9-2.0 ah/m after a warm up
>> > period. But, near the end of the trip with a voltage decline to aro=
und
>> > 140, 1.7-1.8 is a likely measurement,
>>
>> Do you have a way to monitor battery temperature? I know my cells warm
>> up after a sustained 0.5C pull on them. Maybe they are warming up and
>> increasing in efficiency.
>
> Good thought! I have one of those remote sensing (infrared?)
> thermometers that I bought to look for hot terminals. Next trip, I'll
> check cell temperatures before and after. Though I've never noticed
> cells being the least bit warm. My average draw is around 1/3C.
>
> --
> Willie, ONWARD! Through the fog!
> http://counter.li.org Linux registered user #228836 since 1995
> Debian3.1/GNU/Linux system uptime 82 days 4 hours 09 minutes
>
> _______________________________________________
> | REPLYING: address your message to [email protected] only.
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>

-- =

David D. Nelson
http://evalbum.com/1328

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