nerys
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Re: I Beat EPA's 2.9 Miles/KWh : Report Your Monthly Mileage

Thu Sep 25, 2014 10:21 am

I am curious about the difference in these numbers

c. 3.4 Miles / KWh (Wall)
d. 4.2 Miles / KWh (Leaf)

is the in car meter simply not accurate OR is the difference charging overhead and heat losses?

what is the relevance? my only concern is the kWh in the battery when I start the day and how many miles I get on that.

I don't really care about the extra kWh from the wall to run the charger and cooling system and heat loss during charging.

ie my concern is range not power from the socket.

the car says I am averaging 4.9m/kW (and rising) in the 14 days I have had the car 1250 miles in that time.

is that number wrong?
2012 SV 4802miles. 1month 2400 miles. 9 weeks 5000 miles. 6 months 13,300 miles. 4/18 15,000 miles.

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dgpcolorado
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Re: I Beat EPA's 2.9 Miles/KWh : Report Your Monthly Mileage

Thu Sep 25, 2014 11:14 am

nerys wrote:I am curious about the difference in these numbers

c. 3.4 Miles / KWh (Wall)
d. 4.2 Miles / KWh (Leaf)

is the in car meter simply not accurate OR is the difference charging overhead and heat losses?
Perhaps both, but mostly charging overhead. Also, preheating/precooling adds to overhead but not kWh in the battery.
what is the relevance?
The goal is to determine how much electricity the LEAF takes to operate, and that is the number from the "wall".
my only concern is the kWh in the battery when I start the day and how many miles I get on that.

I don't really care about the extra kWh from the wall to run the charger and cooling system and heat loss during charging.

ie my concern is range not power from the socket.
In that case wall numbers are of no concern to you. But the EPA number referenced in this thread is a "wall" number, I believe, so comparing it to a dash meter reading isn't really relevant.
the car says I am averaging 4.9m/kW (and rising) in the 14 days I have had the car 1250 miles in that time.

is that number wrong?
Perhaps. The mileage efficiency meter has been reported to give erroneous results by some, but the numbers I get are consistent with what I would expect from my accurate wall measurements. YMMV.

Other sources of variability: the car's odometer might be a bit off and actual miles traveled versus reported by the odometer will vary somewhat depending on tire type, tire wear, and tire pressure. But the meter should give relative results that can be compared day-to-day and month-to-month.

One problem with the dash meter is that it is coarse: it only reports data to one figure past the decimal point. But that should be plenty good enough for a rough idea of overall mileage efficiency. One concern is that the number on the dash does not usually agree precisely with the mileage efficiency number on the nav console (you have one there too), at least on older LEAFs, such as your 2012 (it would be interesting to see if that has changed on newer LEAFs).

You can reset the meters. I reset my dash meter monthly and the nav console meter each day, just to get an idea of how I was doing that day. The monthly reset is to track seasonality: in the snowbelt mileage efficiency drops considerably in winter versus summer, as one might expect. Others like to leave one meter unchanged to get a sort of "lifetime" mileage efficiency number, although if the 12 V battery is ever disconnected that number will be lost.

Keeping an eye on the mileage efficiency meter, and resetting it periodically, can help in learning to drive the LEAF more efficiently, for those who care about such things.
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DaveinOlyWA
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Re: I Beat EPA's 2.9 Miles/KWh : Report Your Monthly Mileage

Fri Sep 26, 2014 10:53 am

nerys wrote:I am curious about the difference in these numbers

c. 3.4 Miles / KWh (Wall)
d. 4.2 Miles / KWh (Leaf)

is the in car meter simply not accurate OR is the difference charging overhead and heat losses?

what is the relevance? my only concern is the kWh in the battery when I start the day and how many miles I get on that.

I don't really care about the extra kWh from the wall to run the charger and cooling system and heat loss during charging.

ie my concern is range not power from the socket.

the car says I am averaging 4.9m/kW (and rising) in the 14 days I have had the car 1250 miles in that time.

is that number wrong?



when you plug your car in you should hear the faint noise of water pumps kicking in to cool the system. this is a standard overhead that varies little based on charging speed so this is why its good to have faster L2 charging than to use L1 charging. the rest is heat loss on the conversions where L1 wills this battle but the margin is not enough to offset the BMS overhead.

I am at 90% efficiency running at 4.8 KW. the other part as you suspected is the measuring is probably not the best in terms of accuracy either
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nerys
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Re: I Beat EPA's 2.9 Miles/KWh : Report Your Monthly Mileage

Mon Sep 29, 2014 11:15 pm

I am beginning to wonder what the true capacity of the batteries are as they wear down. I think the system is fooled ornis straight up lying about capacity.

I average around 5m per kw. Yet the 8.9m trip to work at 35mph 40max takes a full 2kw as per leaf spy? (19.5kw to 17.5kw) (I really must be stupid. That is 4.5 miles per kw. I guess I am just more exhausted than I realized)

Once I get below 17kw things seems to stabilize and the gom actually becomes pretty damned accurate.

I am thinking my 19.5kw full charge is a fiction and the car rapidly settles down to its true capacity which would explain the rapid gom drop as it keeps recalculating from real time data

The problem I fear is that the capacity meter and by extension nissan is using this ficticious full charge reading instead of the true full charge which I suspect for me is 18.5kw

That would mean my capacity loss is down to 88% not the 90% leaf spy reports??

Not much difference now but could mean a pretty damned big difference at 55,000 miles :-)

Thoughts?
Last edited by nerys on Tue Sep 30, 2014 11:40 am, edited 1 time in total.
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edatoakrun
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Re: I Beat EPA's 2.9 Miles/KWh : Report Your Monthly Mileage

Tue Sep 30, 2014 11:03 am

I have over 3 years of (post-CW-update) Dash/CarWings data now.

As usual, I encourage all LEAF drivers to use actual range/recharge capacity data to find any errors in their cars reported (nominal) kWh use reports, and any errors in the LBC reports of battery capacity, rather than trying to force the data to support either their LEAF's kWh use or LBC battery capacity reports.

(Consolidated reports from CarWings "Regional Rankings" page)

Month and Year Grade Rank Energy Economy

Aug/2011 Bronze 3622 4.2 miles/kWh
Sep/2011 Silver 3457 4.5 miles/kWh
Oct/2011 Silver 3640 4.2 miles/kWh
Nov/2011 Gold 2792 4.2 miles/kWh
Dec/2011 Gold 2827 4.0 miles/kWh
Jan/2012 Gold 2547 4.2 miles/kWh
Feb/2012 Gold 2354 4.4 miles/kWh
Mar/2012 Gold 2975 4.3 miles/kWh
Apr/2012 Gold 3018 4.5 miles/kWh
May/2012 Gold 1978 5.1 miles/kWh
June 2012 5.0 m/kWh
July 2012 5.0 m/kWh
Aug/2012 Platinum 1237 5.7 miles/kWh
Sep/2012 Platinum 1527 5.5 miles/kWh
Oct/2012 Platinum 1368 5.3 miles/kWh
Nov/2012 Platinum 1996 4.7 miles/kWh
Dec/2012 Platinum 1314 4.8 miles/kWh
Jan/2013 Platinum 1240 4.8 miles/kWh
Feb/2013 Platinum 875 5.2 miles/kWh
Mar/2013 Platinum 928 5.5 miles/kWh
Apr/2013 Platinum 1229 5.5 miles/kWh
May/2013 Platinum 1190 5.7 miles/kWh
Jun/2013 Platinum 1557 5.5 miles/kWh
Jul/2013 Platinum 928 5.9 miles/kWh
Aug/2013 Platinum 1442 5.5 miles/kWh
Sep/2013 Platinum 424 6.3 miles/kWh
Oct/2013 Platinum 615 5.9 miles/kWh
Nov/2013 Platinum 1123 5.2 miles/kWh
Dec/2013 Platinum 416 5.5 miles/kWh
Jan/2014 Platinum 331 5.8 miles/kWh
Feb/2014 Platinum 457 5.7 miles/kWh
Mar/2014 Platinum 744 5.5 miles/kWh
Apr/2014 Platinum 567 5.8 miles/kWh
May/2014 Platinum 600 6.0 miles/kWh
Jun/2014 Platinum 452 6.3 miles/kWh
Jul/2014 Platinum 668 6.0 miles/kWh
Aug/2014 Platinum 741 5.9 miles/kWh
Sep/2014 Platinum 497 6.2 miles/kWh (not final)


This Summer my LEAF reported ~6.1 m/kWh nominal.

That's ~30% efficiency increase since 2011.

Part of that increase is from driver efficiency (I more frequently drive low-speed routes, and more often drive relatively slowly on them) and part is probably from an increase in vehicle efficiency, but I believe is nearly certain that there has been a significant change in the common data my LEAF reports as a "kWh" on the dash, Nav screen, and from CarWings.

Each of these "kWh", whether from the top or bottom of the pack, range tests as the same constant unit of energy. And each "kWh" seems to have ~constant Wh capacity from one charge to the next, in the short term.

The question I have tried to answer from range/recharge capacity tests on MY LEAF is whether each of these "kWh", as reported in common on the dash/Nav screen m/kWh and CarWings has actually had a constant Wh content over the last 3+ years (almost certainly not) or how much the Wh content per nominal kWh has increased (the subject of other threads).

In any case, since I finally took my LEAF down to turtle for a long-range test, I can now report that my LEAF still retained more than 100 mile maximum range (~6.1 m/kWh x ~17 kWh x ~1.023 CW/Dash m/kWh odometer error = ~106 miles) in my average driving conditions this Summer.

And I'm pretty happy about that.

7/13/14:

126.1 miles to turtle (5 gids ), 17.0 kWh...

All miles above are as reported by odometer...

KWH use is as reported by dash M/kWh, nav screen M/kWh and Carwings, trip (ERS) and daily.


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dcxplant
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Re: I Beat EPA's 2.9 Miles/KWh : Report Your Monthly Mileage

Mon Oct 27, 2014 11:21 pm

I turn in my 2012 LEAF at the end of the 24 month lease in two weeks.

My average is 4.0, all inclusive since new. On days I stick to town driving and I get 4.5

After two Phoenix summers I've lost two bars, and the battery is at 72% for a loss of 28%.

I've loved every minute of this car, but the range is too short, and the battery has lost and is losing far too much of it's potential for me to consider buying it off lease.

Even with the new "hot weather" battery, I'm not buying or leasing anther LEAF. It was a great experiment, but for our family's busy life with school, baseball, hockey, piano, many days I'm hitting a charger in the middle of my busy day. At first it seemed quaint but as the novelty of the electric car wore off and the battery lost capacity, it's become a burden.

Goodbye LEAF, it was a hoot.

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drees
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Re: I Beat EPA's 2.9 Miles/KWh : Report Your Monthly Mileage

Tue Oct 28, 2014 12:13 am

dcxplant wrote:It was a great experiment, but for our family's busy life with school, baseball, hockey, piano, many days I'm hitting a charger in the middle of my busy day. At first it seemed quaint but as the novelty of the electric car wore off and the battery lost capacity, it's become a burden.

How much range do you think you'd need for an EV to not be a burden on your lifestyle? Or would more charging stations also work with a fresh battery? With all those stops, it seems that there could be enough time for opportunity charging to work if they were available.
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nerys
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Re: I Beat EPA's 2.9 Miles/KWh : Report Your Monthly Mileage

Tue Oct 28, 2014 8:31 am

I personally think 100 miles drop dead range and no more than 10% degredation over 100,000 miles is the key.

This will likely result in a typical range of 175 to 200 miles

(Drop dead range to me would me 0'F outside no garage snowing heat blasting and lights radio etc.. going.

If no matter what you do short of playing speed racer you got n 100 miles.

I think that will be the magic number.

One way they can do this is to softwarr restrict an oversized battery

So maybe you have 220m range. The system will only charge to 80% and only "tell you" it has 150 miles and it did charge to 100% ie lie to you.

This way as battery degrades or temps drop it can software "unlock" some of this range keeping the driving experience unchanged for the end user for much much longer.

That would go a huge way toward improving adoption and reducing average user anxiety and concerns.

I drive 40,000 miles a year minimum (6 weeks 3300 miles on my leaf :-)

100 miles drop dead range would 100% eliminate any issues for me for 99.9% of my driving needs.

For the other .1% i would just use one of my gas cars. No big deal.

Right now the leaf works for me and i dont even have l2 charging yet (should be rectified today)

But it does require careful planning and a state of if its not driving it is charging. Always :-)

The payoff is worth it though. after 20 years of drooling and pining i finally have an ev and it is costing me absolutely nothing over what i was paying before (even with insurance i am spending $100 less than i was spending on gasoline a month!)

And it is the most well built nicest car i have ever owned bar none.

I love my leaf.
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NeilBlanchard
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Re: I Beat EPA's 2.9 Miles/KWh : Report Your Monthly Mileage

Tue Oct 28, 2014 9:35 am

So far, in just the couple of weeks my spouse and I have been driving our Leaf S, we have averaged 4.8 miles / kWh.

I do more coasting than she does, but she is toggling between D and B to slow the car, and we both use Eco at 30-35MPH zones or lower. Tires are at ~40PSI.

NeilBlanchard
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Re: I Beat EPA's 2.9 Miles/KWh : Report Your Monthly Mileage

Fri Oct 31, 2014 7:48 pm

Today, I averaged 5.5 miles / kWh. Not too bad, considering the need for headlights for about some of the time. And stereo, but no heat or fan.

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