STICKY TIME: I Beat The EPA: - Post It Here !

Woo HOOOOO! I think I'm getting 170mpg !!
Or am I. Let's see if I can royally botch the "conversion" process below (kWh into mpg's).
Sorry for the grainy camera phone picture, taken in the glare of the day this Friday -

A 34kWh battery in the Leaf, charged up to 100% will get you down the road 100 miles ... so I'm thinking 5 miles per kWH would be 5(miles) time 34kWh equals 170 miles ?? right?
. . . . . and since 1 gallon of gas equals (appx) 34kWh of energy ... then one gallon is equivalent to 5 miles per kWh ... times 34kWh ... right?
We only have about 300 miles on our Leaf so far . . . . and that's roughly equivalent to the range of one tank of gas.
Any way - EPA says we get 99mpg - so . . . what are other folks doing ... miles per kWh wise.

.

hill said:

Woo HOOOOO! I think I'm getting 170mpg !!
Or am I. Let's see if I can royally botch the "conversion" process below (kWh into mpg's).
Sorry for the grainy camera phone picture, tame in the glare of the day.

A 34kWh battery charged 100% will get you down the road 100 miles ... so I'm thinking 5 miles per kWH would be 5(miles) time 34kWh equals 170 miles ?? right?
. . . . . and since 1 gallon of gas equals (appx) 34kWh of energy ... then that's one gallon ... right?
Any way - EPA says we get 99mpg - so . . . what are other folks doing ... miles per kWh wise.

.

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The Leaf has a 24kwh battery, when I picked up my Leaf I drove it 80 miles and I had 7 miles remaining or ---, I checked on carwings and it showed I used just under 18kwh of energy which would make it 19kwh of useable battery so 5 x 19 = 95. But this would'nt determine mpg, for that you would need to determine how much you will be paying for electricity vs the cost per gallon of gas. So if you are paying $.12 per kwh and you use 19kwh it would be about $2.28 to go 95 miles, @ $4 per gallon that's .57 gallons of gas to go 95 miles or about 167 mpg so you were close but remember this will all change if the price of gas changes of your cost of electricity changes (which will happen when you enter the other tiers of the price per kwh).

cashu2 said:

I checked on carwings and it showed I used just under 18kwh of energy ...

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Don't use carwings numbers. They are optimistic ...

cashu2 said:

The Leaf has a 24kwh battery, . . . . . . . . . . . . . . . snip

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Oh? Hmmm
I haven't read any thing different than wiki :

Under its five-cycle testing, the United States Environmental Protection Agency found the Leaf's energy consumption to be 765 kJ/km (34 kWh/100 miles) and rated the Leaf combined fuel economy equivalent at 99 MPGe (2.4 L/100 km), with an equivalent 106 mpg-US (2.22 L/100 km; 127 mpg-imp) in city driving and 92 mpg-US (2.6 L/100 km; 110 mpg-imp) on highways

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http://en.wikipedia.org/wiki/Nissan_Leaf
There seems to be quite a discrepancy somewhere

hill said:

cashu2 said:

The Leaf has a 24kwh battery, . . . . . . . . . . . . . . . snip

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Oh? Hmmm
I haven't read any thing different than wiki :

Under its five-cycle testing, the United States Environmental Protection Agency found the Leaf's energy consumption to be 765 kJ/km (34 kWh/100 miles) and rated the Leaf combined fuel economy equivalent at 99 MPGe (2.4 L/100 km), with an equivalent 106 mpg-US (2.22 L/100 km; 127 mpg-imp) in city driving and 92 mpg-US (2.6 L/100 km; 110 mpg-imp) on highways

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http://en.wikipedia.org/wiki/Nissan_Leaf
There seems to be quite a discrepancy somewhere

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I guess im wrong about the battery size, regardless the results would be the same. 5 miles per kwh x 34 = 170, 34kwh x $.12 = $4.08 / $4 per gallon = 1.02, 170/1.02 = 166.66mpg. Also I know carwings is optimistic as far as miles per kwh just wasn't sure about the kwh's used, but I know the useable amount is not the full 34kwh because that would mean you can go 170 miles on a single charge.

hill said:

cashu2 said:

The Leaf has a 24kwh battery, . . . . . . . . . . . . . . . snip

Click to expand...

Oh? Hmmm
I haven't read any thing different than wiki :

Under its five-cycle testing, the United States Environmental Protection Agency found the Leaf's energy consumption to be 765 kJ/km (34 kWh/100 miles) and rated the Leaf combined fuel economy equivalent at 99 MPGe (2.4 L/100 km), with an equivalent 106 mpg-US (2.22 L/100 km; 127 mpg-imp) in city driving and 92 mpg-US (2.6 L/100 km; 110 mpg-imp) on highways

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http://en.wikipedia.org/wiki/Nissan_Leaf
There seems to be quite a discrepancy somewhere

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Hill, the battery is 24kWh. The EPA test procedure measures energy used from the wall and does other 'magic' to try to compare an EV with an ICE.

Straight from Nissan - part of their package submitted to the EPA:
http://www.mynissanleaf.com/viewtopic.php?f=4&t=2433
http://www.smidgeindustriesltd.com/leaf/EPA/FOI-BNSXV0000LLA.pdf

hill said:

Under its five-cycle testing, the United States Environmental Protection Agency found the Leaf's energy consumption to be 765 kJ/km (34 kWh/100 miles) and rated the Leaf combined fuel economy equivalent at 99 MPGe (2.4 L/100 km), with an equivalent 106 mpg-US (2.22 L/100 km; 127 mpg-imp) in city driving and 92 mpg-US (2.6 L/100 km; 110 mpg-imp) on highways

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http://en.wikipedia.org/wiki/Nissan_Leaf
There seems to be quite a discrepancy somewhere

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I believe the discrepancy is in your understanding of what MPGe means.

wikipedia said:

Miles per gallon gasoline equivalent (MPGe or MPGge) is a measure of the average distance traveled per unit of energy consumed.

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[underlining added]

MPGe is a mapping using the energy in electricity compared to the energy in gasoline. You can't get there with the sort of calculation you were doing.

Ray

Gary; do you have a way to accurately measure power used from the wall to your Leaf?

i do and i compare readings on my car (reset Trip B daily, Trip A weekly) and the ratio of DMPK (reading on car) to AMPK (power from wall) was 73% for March. that is actually slightly higher than Feb but i think that might be because i am moving away from charging to 100%.

all my charging is at 120 volts so wondering if anyone has #'s on 240 volt charging to compare efficiencies.

now as much as i think the car's values are off, i will say they are consistent much more so than Carwings, so i take a lot more stock in monitoring those #'s

also; you may find a different result, but my experience appears to indicate that i only have around 21 KWH to use

DaveinOlyWA said:

also; you may find a different result, but my experience appears to indicate that i only have around 21 KWH to use

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Measuring from where? Mike Walch's hypothesis is that each of the 12 bars represents about 2 kWh when the battery is new. The bars disappear in the middle of the 2 kWh range (so the first one drops out after using only 1 kWh of energy). When you drop to a single bar that would say you still have about 3 kWh left. Would that be the point at which you are recharging?

Ray

DaveinOlyWA said:

Gary; do you have a way to accurately measure power used from the wall to your Leaf?

i do and i compare readings on my car (reset Trip B daily, Trip A weekly) and the ratio of DMPK (reading on car) to AMPK (power from wall) was 73% for March. that is actually slightly higher than Feb but i think that might be because i am moving away from charging to 100%.

all my charging is at 120 volts so wondering if anyone has #'s on 240 volt charging to compare efficiencies.

now as much as i think the car's values are off, i will say they are consistent much more so than Carwings, so i take a lot more stock in monitoring those #'s

also; you may find a different result, but my experience appears to indicate that i only have around 21 KWH to use

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Thanks for the data/help dave ... man - if you want to calculate out a number the equates to comparable gas use (rather than the simple 34kWh wiki number) it looks like it'll be a bit tricky. Despite what gas costs ... or despite what electricity costs, it was my hope that running a few quick numbers would be the "equivalent" number.

Bummer. OK then - the Leaf has a gauge that shows (approximately) "Miles per kWh. If the EPA's MPGe number is (appx) 99 MPGe ... what would the Leaf's "Miles Per kWh" readout be, if one drove 99 miles on one charge?.
... would that work out to be a reasonable equivalence ?

And no ... I don't have a way to measure 240V use. I wish the had a Kill-a-Watt equivalent device that didn't cost a fortune ... or if they do, I haven't found it yet.

I'm averaging about 4.4 Miles/Kw as shown by the car.

hill said:

And no ... I don't have a way to measure 240V use. I wish the had a Kill-a-Watt equivalent device that didn't cost a fortune ... or if they do, I haven't found it yet.

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So, I guess $120 for a TED with comparable function qualifies as "a fortune"?

Ray

planet4ever said:

hill said:

And no ... I don't have a way to measure 240V use. I wish the had a Kill-a-Watt equivalent device that didn't cost a fortune ... or if they do, I haven't found it yet.

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So, I guess $120 for a TED with comparable function qualifies as "a fortune"?
Ray

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Yea, for me, 6x higher than the price of a 120V kill-a-watt is my threshold for becoming "a fortune"

hill said:

Yea, for me, 6x higher than the price of a 120V kill-a-watt is my threshold for becoming "a fortune"

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considering your power from the Sun, i would not bother either. how much excess do you have? you have a what?? 40-50 mile RT commute? that equates to about 250-300 kwh a month with a bit extra tossed in for side trips and that is driving "normally" so u could shave 20-50 kwh if you wanted to.

planet4ever said:

DaveinOlyWA said:

also; you may find a different result, but my experience appears to indicate that i only have around 21 KWH to use

Click to expand...

Measuring from where? Mike Walch's hypothesis is that each of the 12 bars represents about 2 kWh when the battery is new. The bars disappear in the middle of the 2 kWh range (so the first one drops out after using only 1 kWh of energy). When you drop to a single bar that would say you still have about 3 kWh left. Would that be the point at which you are recharging?

Ray

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be a "psyche" job or maybe our overall lack of specific verifiable information or a combo of... but ya.

its like a real gas tank. the last part of the gauge nearly always runs below the empty needle. we call it reserve or maybe the car's emphasis that you need to refill. so u never use the last drop (or at least you should not) and u never really have it completely full. u stated it yourself, the first bar is a lesser value and i contend the last one is as well

so, ya when we get to the last bar i do believe it holds more value than the previous bars. now i have only gotten to turtle mode one time. but have gotten to the last bar a half dozen times, including one time where i drove over 10 miles when i was supposed to have about 6 miles of range left and did not hit turtle mode then.

now, we have Nissan telling us we have 24 kwh usable but with little other details. hopefully, by now. the speculation that the battery pack is larger than 24 kwh has ended, but maybe it has not but the only thing i can go by is my observation and my willingness to push the boundaries of the range.

to be honest with ya. i am pretty much done (for the most part) with the experimentation of the range. i will revisit this when i suspect my battery pack's capabilities have changed enough. but i did this to learn the car. i think i have enough to operate the car with a minimal risk of being stranded.

hill said:

STICKY TIME: I Beat The EPA: - Post It Here !Posted: Fri Apr 01, 2011 7:52 pm

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Getting back to your original topic - let us see what what "beating the epa" in Leaf means.

The main efficiency (or as they say energy economy) figure from epa is 34 kwh/100 miles. This turns to 2.9 miles/kwh. This kwh should be calculated at the wall - not carwings or what the car shows. This means, you should either have TED/kill-a-watt, separate meter or Blink to figure out the energy used by the car at the wall. We should also keep track of any charges done when not at home.

We could do this on a monthly basis.

For March, I get 3.2 miles/kwh. So, yes, I beat the EPA figure. My guess is most of us do ...

My guess is that your guess is correct. My sig reflects what. I pay for which is power from the wall

I've posted a new sticky thread on this.

http://www.mynissanleaf.com/viewtopic.php?f=31&t=3207&start=0

DaveinOlyWA said:

be a "psyche" job or maybe our overall lack of specific verifiable information or a combo of... but ya.

its like a real gas tank. the last part of the gauge nearly always runs below the empty needle. we call it reserve or maybe the car's emphasis that you need to refill. so u never use the last drop (or at least you should not) and u never really have it completely full. u stated it yourself, the first bar is a lesser value and i contend the last one is as well

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You could be right, Dave, but based on the info from the service manual, it looks like all the bars are equally biased. I don't expect this digital system is be programed to emulate the weaknesses of a float-driven fuel gauge, but certainly could be.

DaveinOlyWA said:

now, we have Nissan telling us we have 24 kwh usable but with little other details. hopefully, by now. the speculation that the battery pack is larger than 24 kwh has ended, but maybe it has not but the only thing i can go by is my observation and my willingness to push the boundaries of the range.

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24kWh usable is documented, has been tested by other members, and has been confirmed by Ingineer and EVDRIVER using a Nissan factory diagnostics tool. The 'white bars' of the fuel gauge should show us 20kWh and the two 'red bars' show 4kWh. Keep in mind that the red bars are on the 'pack degradation' or 'total battery capacity' display - not the fuel gauge - so the 'warning' is about 'excessive fuel tank shrinkage' not about driving too far on a tank...if that makes sense to anyone else but me... (hmmm...and if it does, you might want to be a little bit concerned... ...or not... )

DaveinOlyWA said:

to be honest with ya. i am pretty much done (for the most part) with the experimentation of the range. i will revisit this when i suspect my battery pack's capabilities have changed enough. but i did this to learn the car. i think i have enough to operate the car with a minimal risk of being stranded.

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This I can understand! It's a LOT more fun to skip the tedium and just DRIVE!

Well looks like we back to not relying on the cars figures...not too surprised about that