jlsoaz
Posts: 582
Joined: Sun Jul 08, 2012 12:57 pm
Delivery Date: 10 Oct 2012
Leaf Number: 24218
Location: Southern Arizona, USA

Re: Price to retrofit a used 2011-2015 Leaf with a new 30 kWh (or higher) battery?

Wed Apr 13, 2016 4:02 pm

wwhitney wrote:
jlsoaz wrote: My understanding (and going from memory) is that a gallon of gasoline when combusted will release anything from (very roughly) under 100,000 btu to more than 130,000 btu.

Your comment got me curious so I decided to check wikipedia. The fuels commonly called gasoline produce between 111,000 and 115,000 BTUs/gallon, so the range is much tighter. But diesel produces 130,000 BTUs/gallon, while E85 produces only 82,000 BTU/gallon.

Cheers, Wayne


Hello Wayne,

if we go by the link you provided, then I guess, but it is just one link. I suppose it is possibly correct that that the range in reality is tighter than the range of numbers I ran into when researching this years ago, but I think part of the problem is if I checked different sources I ran into different numbers and sometimes differing more widely than you have mentioned. If we take a quick check now we see also this:

https://en.wikipedia.org/wiki/Gasoline#Energy_content

Gasoline contains about 42.4 MJ/kg (120 MJ/US gal, 33.3 kWh/US gal, 120,000 BTU/US gal) quoting the lower heating value. [6] Gasoline blends differ, and therefore actual energy content varies according to the season and producer by up to 4% more or less than the average, according to the US EPA.


In my own calculations I eventually ended using something in the 33.x-34.x kWh per gallon range.

It has been too many years since my last chemistry class for me to have a handle on incorporating LHV and HHV understanding into the conversation, but the point was and is basically that when I went to look into these things, I found a range, and this brought home that the energy released when combusting a US gallon (or for that matter, a kilogram) of the fuel is not consistently the same across all gallons and this is logical I think because it is not just one set molecule but

"It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives."


This is not to treat wikipedia as that reliable, but for purposes of a quick look at something.
josh@jlaz.com
near Tucson, AZ, USA
Former lessee 2012 SL
http://www.pluginamerica.org/surveys/batteries/leaf/vehicle.php?vid=229
opinions expressed are my own

wwhitney
Posts: 650
Joined: Sat Jul 17, 2010 10:10 am
Delivery Date: 01 Apr 2011
Location: Berkeley, CA

Re: Price to retrofit a used 2011-2015 Leaf with a new 30 kWh (or higher) battery?

Wed Apr 13, 2016 7:59 pm

OK, so maybe the range is not quite so tight as 111 - 115 kBTUs/gal. If the +/- 4% figure is to be believed it is more like 109 - 117 kBTUs/gal or a comparable range. Very good.

As to the LHV/HHV question, it appears the numbers being quoted are lower heating values. That means they are the energies released when the exhaust gases are at 150C, and in particular the water formed from combustion is still a vapor. The LHV/HHV difference is like the difference between non-condensing and condensing natural gas appliances.

Cheers, Wayne

XeonPony
Posts: 313
Joined: Sun Nov 03, 2013 5:58 pm
Delivery Date: 03 Nov 2013
Leaf Number: 413826
Location: Yorkton, sask, Canada

Re: Price to retrofit a used 2011-2015 Leaf with a new 30 kWh (or higher) battery?

Thu Apr 14, 2016 8:11 am

wwhitney wrote:
cwerdna wrote:And, various .gov sites say that 1 gallon of gasoline is equivalent to 33.7 kWh.

Just to clarify, that's equivalent in the sense that if a magic engine could completely burn gasoline and convert all the energy released into electricity, it would generate 33.7 kWh/gallon of gas. If you had such a 100% efficient engine, in a Volt, say, and you usually drive at an efficiency of 4 mi/kWh, then you could get 135 mpg. The fact than the Volt gets only 40-50 mpg when run on gas alone (I forget the exact number) shows that real gas engines are more like 30% efficient.

Cheers, Wayne


30% Would be astronomical compared to what it really is, the best engine we have does 21% at ideal conditions! Usually after a couple hundred hours of run time we get about average of 15%
2013 SV Leaf, Level 2 charger, so far all works great! 130Km daily, 100% charge at night on 240 then trickle charge for 8H durring the day on 120v.

Level 2 charge starts at 130am environmental starts at 6am to 25c for a toasty warm defrosted car!

wwhitney
Posts: 650
Joined: Sat Jul 17, 2010 10:10 am
Delivery Date: 01 Apr 2011
Location: Berkeley, CA

Re: Price to retrofit a used 2011-2015 Leaf with a new 30 kWh (or higher) battery?

Thu Apr 14, 2016 10:40 am

XeonPony wrote:30% Would be astronomical compared to what it really is, the best engine we have does 21% at ideal conditions! Usually after a couple hundred hours of run time we get about average of 15%

Hmm, I don't know much about gas engines, but I also don't see anything wrong with my calculation.

Here's another data point: Fueleconomy.gov rates the BMW i3 REX at 29 kWh or 2.6 gallons of gas for 100 miles of travel. At 33.7 kWh/gallon of gas, that makes its gas engine 29 / (2.6 * 33.7) = 33% efficient.

So why the difference?

Cheers, Wayne

philip
Posts: 106
Joined: Tue Nov 27, 2012 8:18 pm
Delivery Date: 25 Aug 2015
Leaf Number: 327341
Location: El Cajon, CA

Re: Price to retrofit a used 2011-2015 Leaf with a new 30 kWh (or higher) battery?

Fri Apr 15, 2016 9:04 am

XeonPony wrote:30% Would be astronomical compared to what it really is, the best engine we have does 21% at ideal conditions! Usually after a couple hundred hours of run time we get about average of 15%


Any reference for the 21% number?

Wärtsilä heavy fuel oil engines claim part load efficiency above 50% and full load is around 48%.
Returned 11/11/15: 2012SL - 10 bar, SOH76% 49.97AHr 35,644mi vin 26790
White 2015 SV Purchased

XeonPony
Posts: 313
Joined: Sun Nov 03, 2013 5:58 pm
Delivery Date: 03 Nov 2013
Leaf Number: 413826
Location: Yorkton, sask, Canada

Re: Price to retrofit a used 2011-2015 Leaf with a new 30 kWh (or higher) battery?

Fri Apr 15, 2016 9:21 am

in perfect condition in a static environment, in real world conditions oil viscosity, air temp, wind direction factor in along with gear train lash/end play, as the engine ages it just gets lower and lower.


So from the gas to wheels turning net efficiency is usually very low, 33% is dismal given the age of the technology.

https://www.fueleconomy.gov/feg/atv.shtml
2013 SV Leaf, Level 2 charger, so far all works great! 130Km daily, 100% charge at night on 240 then trickle charge for 8H durring the day on 120v.

Level 2 charge starts at 130am environmental starts at 6am to 25c for a toasty warm defrosted car!

jlsoaz
Posts: 582
Joined: Sun Jul 08, 2012 12:57 pm
Delivery Date: 10 Oct 2012
Leaf Number: 24218
Location: Southern Arizona, USA

Re: Price to retrofit a used 2011-2015 Leaf with a new 30 kWh (or higher) battery?

Fri Apr 15, 2016 12:24 pm

XeonPony wrote:in perfect condition in a static environment, in real world conditions oil viscosity, air temp, wind direction factor in along with gear train lash/end play, as the engine ages it just gets lower and lower.


So from the gas to wheels turning net efficiency is usually very low, 33% is dismal given the age of the technology.

https://www.fueleconomy.gov/feg/atv.shtml


I tend to think of it as PEVs and to a lesser extent FCVs, while not at all perfectly efficient, offer a way around Carnot Cycle related (and some other) efficiency issues. With that being said, I'm wondering if sometimes ICVs overall get a somewhat unfair rap mathematically to the extent that they can make more use of "waste" heat in some situations than is sometimes clear from the base-level efficiency analysis. I.e.: they can in effect do co-gen. I suppose as well FCVs and PEVs can as well make use of waste heat, just noting as to ICVs.
josh@jlaz.com
near Tucson, AZ, USA
Former lessee 2012 SL
http://www.pluginamerica.org/surveys/batteries/leaf/vehicle.php?vid=229
opinions expressed are my own

jlsoaz
Posts: 582
Joined: Sun Jul 08, 2012 12:57 pm
Delivery Date: 10 Oct 2012
Leaf Number: 24218
Location: Southern Arizona, USA

Re: Price to retrofit a used 2011-2015 Leaf with a new 30 kWh (or higher) battery?

Fri Apr 15, 2016 12:48 pm

taloyd wrote:
powersurge wrote:I would like to make a motion for people to stop correcting other members posts when it is clear what they are saying. [...] Would you correct people's speech when you are face to face with them?


cwerdna wrote:They didn't ask to be corrected since they probably didn't realize they were wrong. Just because you see it "all the time" doesn't make it right. If EV enthusiasts can't get it right and develop good habits (and pass along proper information to others), how can we expect others to get it right?



Cwerdna is doing a public service and should be lauded as such - I've actually never seen an explanation as elegant as kW = HP and kWH = gallons before.

Disseminating false information, or (even worse) knowingly propagating incorrect usage of technical details is counter-productive. This is a forum for people to learn about Nissan Leafs/EVs - this is exactly the place where it should be corrected. Please don't encourage suppressing speech - especially exactly the sort of speech that CLEARS up misconceptions and ADDS to the pool of [correct, useful] knowledge.

I'll leave it alone now - just amazed/offended someone would go out of their way to admonish someone for providing useful, correct information in favor of misleading/false information.


Upon reconsideration, especially since Cwerdna was reasonably polite in their original correcction, I can see most of your point, but my first reaction to PowerSurge was some support and I still think they had at least one good point. Many of us are well-accustomed to the kW and kWh mistake being made wide and far, and when addressing the mistake, especially if it is made by a newbie, depending on how it is done, there is some danger of turning off folks who really just wanted to have conversation and ask questions. If the correction is made somewhat aggressively, and if it is done at the cost of the main topic, then this can particularly be a turnoff.

PowerSurge makes a comparison to the sort of turnoff that can accompany being corrected on speech - it depends on how and why, but I think more often than not, one chooses to let speech mistakes pass, as this is (more often than not) the polite thing to do.

In any event, considering how many decades the kW/kWh mistake has been made and how often, and by how many, and how central it is to EV conversation, it does seem perhaps worthwhile to say it's not the same thing as trying to correct speech in general conversation. I just thought I'd say that
1) I think there is a point to making sure to be super-polite about it so that newcomers to the space understand we are not trying to correct them in a way that is a turnoff.
2) There is also a danger of distracting from whatever topic is at hand. In this case, as the originator of the thread, I was really glad to see Yogi62 address themselves to the thread topic and related (what would a person pay)... an overall subject that for me still has more to be said.... and they did this a few months since the last post. I think Yogi62 is really to be credited with that and while I was aware they made the kW/kWh mistake, it was of relatively less importance to me compared to the possibility of continuing the parts of the discussion relating to the original topic.

Cwerdna did then also address themselves to the thread topic in the same post as their correction, and that's good.

This is *not* to complain about the fact that we have gone off since then on other tangents. I love the efficiency topics,and regardless of whether I love them, I think folks should feel empowered to enjoy the discussions here and make all manner of points on all manner of topics, and not needlessly get into attempted topic-copping.

I do though want to say thanks to Yogi62 and Cwerdna for providing more input on the basic thread topic.
josh@jlaz.com
near Tucson, AZ, USA
Former lessee 2012 SL
http://www.pluginamerica.org/surveys/batteries/leaf/vehicle.php?vid=229
opinions expressed are my own

gschettl
Posts: 26
Joined: Wed Jun 06, 2012 5:57 am
Delivery Date: 05 Jun 2012
Leaf Number: 020169
Location: jordan minnesota 55352 (Minneapolis suburb)

Re: Price to retrofit a used 2011-2015 Leaf with a new 30 kWh (or higher) battery?

Sun Apr 24, 2016 3:11 pm

Assuming Nissan will never offer an official retrofit option to replace the 24 kWh battery in my 2012 SL with a 30 kWh... is there anybody out there poised to do this retrofit unofficially. It's my preference to keep my chassis & swap my original 24 kWh battery for a new or slightly used 30 kWh battery, but I don't have the time nor skill to do such a swap, (unless I was offered a plug and play set-up). Also I wouldn't care if the SOC bars etc. were correct, but I understand the battery management system changes with the 30 kWh battery.

jlsoaz
Posts: 582
Joined: Sun Jul 08, 2012 12:57 pm
Delivery Date: 10 Oct 2012
Leaf Number: 24218
Location: Southern Arizona, USA

Re: Price to retrofit a used 2011-2015 Leaf with a new 30 kWh (or higher) battery?

Sun Apr 24, 2016 5:10 pm

gschettl wrote:Assuming Nissan will never offer an official retrofit option to replace the 24 kWh battery in my 2012 SL with a 30 kWh... is there anybody out there poised to do this retrofit unofficially. It's my preference to keep my chassis & swap my original 24 kWh battery for a new or slightly used 30 kWh battery, but I don't have the time nor skill to do such a swap, (unless I was offered a plug and play set-up). Also I wouldn't care if the SOC bars etc. were correct, but I understand the battery management system changes with the 30 kWh battery.


There must be someone, but so far the only thing I"ve seen is this very dubious claim from a few months ago:

http://cleantechnica.com/2016/01/19/3rd ... to-48-kwh/
3rd-Party Nissan LEAF Battery Pack Upgrades — Doubling To 48 kWh
January 19th, 2016 by James Ayre

I can't even find a reliable web page for these folks, I doubt I'd trust them with a major vehicle after-market change.
josh@jlaz.com
near Tucson, AZ, USA
Former lessee 2012 SL
http://www.pluginamerica.org/surveys/batteries/leaf/vehicle.php?vid=229
opinions expressed are my own

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