GroundLoop
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Joined: Mon Sep 13, 2010 9:31 pm

Re: Leaf Miles / KWh is Wrong Or Usable bat. cap. is not 24

Sun May 29, 2011 11:52 am

DaveinOlyWA wrote:AMPK= AC miles per kwh which would be..."wall" power
We'll have to rethink this when someone starts DC Quick-charging, or direct-DC charging off Solar.
DMPK= DC miles or "battery" power.
I can't use these units because I don't have a direct view of DC (battery output) kWh. Assigning specific units to something inferred, approximated, or variable just makes for confusing results later.

Miles we can measure accurately.
"Wall" kWh we can measure accurately at the source.
Battery kWh, that's still Nissan's secret. Because of this, charger efficiency is also a debatable ratio.

If I had a favorite summary unit, it would be:
Wall Watt-hours per Mile.
Consumed Watt-hours per Mile?
And for now, A/C Wh per mile.

Because MPG is still our unfortunate unit for ICE, mi/kWh is a natural analog. It's still upside-down, though. :)

For instantaneous readout on the dash, my favorite values would be:
- Useable Wh remaining in the Battery.
- Instantaneous Watts Per Mile

Bonus values:
- Average Watts per Mile for 1, 5, and 20 miles.
- Wh used from Battery since last charge.
- Instantaneous Watts

LEAFguy
Posts: 548
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Location: San Diego
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Re: Leaf Miles / KWh is Wrong Or Usable bat. cap. is not 24

Sun May 29, 2011 12:52 pm

GroundLoop wrote:I care about two things:

1) Cost per mile, which becomes Miles per kWh as a normalized measure. (I prefer Watts per Mile)

2) Useable Range, and predicted range while driving, because it impacts planning and useability
GroundLoop - this is exactly what I've been saying. If we are truly interested in advancing the EV (LEAF and others), this is what people want to know. How much is it going to cost me to drive it? How far can I go? We need to educate others that the LEAF is a tool. You own a specific tool for a specific purpose.

It was recently called out in another thread that TRONZ owns a LEAF, an F350 SuperDuty, and a GSXR1000. Three radically different vehicles, yet I suspect that he bought each for three different purposes. When we discuss our LEAF with others, we always say that the LEAF is the perfect situational vehicle - but if your situation is not the same as ours it may not be the right vehicle for you. Then again, neither is an F350 or a GSXR1000. One day, EVs will go further and cost less. One day publicly available EVSE's will be abundant. One day, people will say "Why did it take so long?" What we can do now is to help others understand that the LEAF is a really great car. But it may not be the right car for you - yet.

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evnow
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Delivery Date: 25 Feb 2011
Leaf Number: 303
Location: Seattle, WA

Re: Leaf Miles / KWh is Wrong Or Usable bat. cap. is not 24

Sun May 29, 2011 1:03 pm

LEAFguy wrote:When we discuss our LEAF with others, we always say that the LEAF is the perfect situational vehicle - but if your situation is not the same as ours it may not be the right vehicle for you.
Exactly.

Similarly, there are people for whom m/kwh or the usable battery capacity is important. May be not for others :lol:
1st Leaf : 2/28/2011 to 5/6/2013
2nd Leaf : 5/4/2013 to 3/21/2017
Volt : 3/25/2017 to 5/25/2018
Model 3 : 5/10/2018 to ?

SparkyEV
Posts: 97
Joined: Tue May 17, 2011 4:15 pm
Delivery Date: 09 Jun 2011
Leaf Number: 3651
Location: San Jose, CA

Re: Leaf Miles / KWh is Wrong Or Usable bat. cap. is not 24

Sun May 29, 2011 9:24 pm

JessEV wrote:My assumption is that each bar represents 2kWh since there are 12 and it is a stated 24kWh battery.
I thought I read that while it is a 24 kWh pack, not all of that is available for use. There's a 'protective cushion' at the top & the bottom, leaving about ~21-22 kWh effective (0-100% Soc). This is done to extend the life of the battery.
2016 SV (30kWh)
@500 miles: AHr=79.88 SOH=100 Hx=95.3, GIDs=363
Was: 2011 Blue Ocean Leaf SL. Retired with 62k miles and 3 bars down.
My daily commute: 55 miles round trip, 92% freeway @ 55-60MPH, 5.0 miles/kWh average (per the dash)

jwatte
Posts: 132
Joined: Wed May 25, 2011 5:44 pm
Delivery Date: 14 Jul 2011

Re: Leaf Miles / KWh is Wrong Or Usable bat. cap. is not 24

Sun May 29, 2011 9:43 pm

Herm wrote:Some people could care less about CO2.. in any case power at my outlets is CHEAP, only $0.11 a KWh
I imagine you meant "couldn't care less"?

Anyway, where do you get juice for $0.11/kWh? At PG&E, my "baseline" usage is 8 kWh, and my house draws about 20 kWh per day before I've even added a car. Server computer, waterbed, aquarium, freezer, networking gear, three kids... it adds up! And past baseline, I pay about $0.48/kWh. Makes solar installations start looking appealing, if my house wasn't surrounded by trees. (And the city has a tree preservation ordinance)

SparkyEV
Posts: 97
Joined: Tue May 17, 2011 4:15 pm
Delivery Date: 09 Jun 2011
Leaf Number: 3651
Location: San Jose, CA

Re: Leaf Miles / KWh is Wrong Or Usable bat. cap. is not 24

Sun May 29, 2011 11:08 pm

jwatte wrote:At PG&E, my "baseline" usage is 8 kWh, and my house draws about 20 kWh per day before I've even added a car. Server computer, waterbed, aquarium, freezer, networking gear, three kids... it adds up! And past baseline, I pay about $0.48/kWh. Makes solar installations start looking appealing, if my house wasn't surrounded by trees. (And the city has a tree preservation ordinance)
Can't you switch to PG&E's TOU E-9 rates for EVs? It's less than $0.06/kWh for off-peak usage.
2016 SV (30kWh)
@500 miles: AHr=79.88 SOH=100 Hx=95.3, GIDs=363
Was: 2011 Blue Ocean Leaf SL. Retired with 62k miles and 3 bars down.
My daily commute: 55 miles round trip, 92% freeway @ 55-60MPH, 5.0 miles/kWh average (per the dash)

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planet4ever
Posts: 4674
Joined: Sat Apr 03, 2010 9:53 pm
Delivery Date: 02 May 2011
Leaf Number: 1537
Location: Morgan Hill, CA, south of San Jose

Re: Leaf Miles / KWh is Wrong Or Usable bat. cap. is not 24

Sun May 29, 2011 11:18 pm

SparkyEV wrote:I thought I read that while it is a 24 kWh pack, not all of that is available for use. There's a 'protective cushion' at the top & the bottom, leaving about ~21-22 kWh effective (0-100% Soc). This is done to extend the life of the battery.
It may be 24 kWh total, or maybe 27 kWh, or even more. It may be 24 kWh usable, or as little as 21 kWh, or possibly even less. There could be a 15% protective cushion, or maybe 20%, or only 10%, possibly even less than that. It's mostly all speculation at this point. We don't have enough facts to nail down the truth.

Ray
End of April 2013: Traded my 2011 SL for a 2013 S with charge pkg.

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planet4ever
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Location: Morgan Hill, CA, south of San Jose

Re: Leaf Miles / KWh is Wrong Or Usable bat. cap. is not 24

Sun May 29, 2011 11:42 pm

SparkyEV wrote:
jwatte wrote:At PG&E, my "baseline" usage is 8 kWh, and my house draws about 20 kWh per day before I've even added a car. Server computer, waterbed, aquarium, freezer, networking gear, three kids... it adds up! And past baseline, I pay about $0.48/kWh. Makes solar installations start looking appealing, if my house wasn't surrounded by trees. (And the city has a tree preservation ordinance)
Can't you switch to PG&E's TOU E-9 rates for EVs? It's less than $0.06/kWh for off-peak usage.
It's not nearly that simple. In the first place there is E-9a and E-9b. E-9b has some very hefty startup costs. E-9a means the EV is sharing the tier allotment with the rest of the house. If jwatte is paying $0.48, they must already be using something like E6 TOU and be at tier 3, and he is quoting the peak rate. Peak rate tier 3 for E-9a is $0.46, nearly as bad. And tier 3 off peak is $0.15, not $0.06.

Ray
End of April 2013: Traded my 2011 SL for a 2013 S with charge pkg.

SparkyEV
Posts: 97
Joined: Tue May 17, 2011 4:15 pm
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Leaf Number: 3651
Location: San Jose, CA

Re: Leaf Miles / KWh is Wrong Or Usable bat. cap. is not 24

Mon May 30, 2011 8:47 am

planet4ever wrote:It's not nearly that simple. In the first place there is E-9a and E-9b. E-9b has some very hefty startup costs. E-9a means the EV is sharing the tier allotment with the rest of the house. If jwatte is paying $0.48, they must already be using something like E6 TOU and be at tier 3, and he is quoting the peak rate. Peak rate tier 3 for E-9a is $0.46, nearly as bad. And tier 3 off peak is $0.15, not $0.06.

Ray
That's true, I was quoting tier 1 rates and I should have been more clear about that in my post. I plan on going with E9-B myself, in order to keep most of the EV usage in tier 1. The upfront costs are $250 for the meter plus the cost to have an electrician install a second panel. I expect to recover these costs in the first year because of the advantage over sharing the baseline with the rest of the house under E9-A.

In any case, jwatte could do much better than $0.48/kWh with no additional costs by switching to E9-A and charging during off-peak hours.
2016 SV (30kWh)
@500 miles: AHr=79.88 SOH=100 Hx=95.3, GIDs=363
Was: 2011 Blue Ocean Leaf SL. Retired with 62k miles and 3 bars down.
My daily commute: 55 miles round trip, 92% freeway @ 55-60MPH, 5.0 miles/kWh average (per the dash)

jwatte
Posts: 132
Joined: Wed May 25, 2011 5:44 pm
Delivery Date: 14 Jul 2011

Re: Leaf Miles / KWh is Wrong Or Usable bat. cap. is not 24

Mon May 30, 2011 12:50 pm

SparkyEV wrote: Can't you switch to PG&E's TOU E-9 rates for EVs? It's less than $0.06/kWh for off-peak usage.
That would not save me money, because the peak time draw (which is when AC and kid computers run and whatnot) would be billed at a higher rate.
I'm looking at E-9B rates, with the option of a second meter (although the installation charge for that -- ouch!)
What I don't understand is that the rate goes all the way up to Tier 5 for the E-9B. Peak use at Tier 5 is $0.57 with that rate!

Given the $4k install for a second meter, though, I probably should put in a kilowatt or two of PV solar instead -- would probably pay itself back sooner :-)

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