JoeS
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Posts: 3802
Joined: Thu Dec 15, 2011 5:47 am
Location: Silicon Valley, California

Re: Measured Wall-to-Wheels Consumption

Tue Aug 21, 2012 5:42 am

OMG joev, your average energy consumption is better than my 'best' measured interval! Just goes to show how well the iMiEV performs if the speeds are kept low. Whereabouts are you located and what are you using to make your measurements?
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

joev
Posts: 53
Joined: Sun Jul 01, 2012 3:07 am
Location: Long Island, NY

Re: Measured Wall-to-Wheels Consumption

Tue Aug 21, 2012 10:45 am

To Joes:
Best on one charge was 6.1m/kWh (9.8km/kWh)
Worst on one charge was 4.5m/kWh (7.2km/kWh)

Located: Long Island (South Shore), NY (nice and flat here but I do see some slight grades in the road).

I have a current transformer with a digital readout inline to my level 2 charging station. The CT was used in my PV grid tied system for 12 year and is quite accurate. It gives instant and cumulative info and is resettable. I can't chart the whole charge time in a graph but I know the watt rate varies throughout the charge especially in the beginning and at the end.

LOW SPEED = MORE RANGE/kWh no denying it.

Let me know if you want more info on my data collecting.

JoeS
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Posts: 3802
Joined: Thu Dec 15, 2011 5:47 am
Location: Silicon Valley, California

Re: Measured Wall-to-Wheels Consumption

Tue Aug 21, 2012 12:36 pm

joev wrote:I have a current transformer with a digital readout inline to my level 2 charging station. The CT was used in my PV grid tied system for 12 year and is quite accurate. It gives instant and cumulative info and is resettable. I can't chart the whole charge time in a graph but I know the watt rate varies throughout the charge especially in the beginning and at the end.
joeev, thank you for that information.

I use a TED 5000 which gives me computer graphing of instantaneous power and cumulative kWhr (by hour, day, month). Unlike you, my power consumption readings are very constant (e.g., 906W at 120vac +/- just a few watts) and even vary very little with line voltage changes. The charger usually takes exactly a ten-minute break at some point in the charging cycle (to check cell sag is my guess) and at the very end there is a measured power reduction which lasts about 1/2-hour as the cells are top-balanced (my guess).
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

joev
Posts: 53
Joined: Sun Jul 01, 2012 3:07 am
Location: Long Island, NY

Re: Measured Wall-to-Wheels Consumption

Tue Aug 21, 2012 12:57 pm

Joes:
Sounds correct about the charge cycle.
Mine starts at ~ 3.3kw then settles in at ~ 3.2kw

There is a period that it drops off for about 10 minutes.

At the end of the charge cycle it slowly tapers off to about .2kw then shuts off.

Like I said this is just from observing the read out at different times. I really don't care what its doing; I just want to know the amount of energy it is using to recharge.

Don
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Joined: Thu May 10, 2012 3:55 pm
Location: Biloxi MS

Re: Measured Wall-to-Wheels Consumption

Tue Aug 21, 2012 4:31 pm

I've wondered how much the hill Joe lives on 'costs' him in juice - It takes some extra for him to get up to where he lives everytime he returns home . . . . and he doesn't get all of that energy back by regenning going back down the hill when he leaves. I would expect anyone who lives on relatively flat ground should have slightly better numbers . . . . and then lower speeds really help too - How far did you compute the car would go at a steady 22 mph Joe? I recall it was something over 400 miles on one charge, wasn't it?

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2017 Chevy Volt Premier
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1979 Honda CBX six into six

joev
Posts: 53
Joined: Sun Jul 01, 2012 3:07 am
Location: Long Island, NY

Re: Measured Wall-to-Wheels Consumption

Tue Sep 11, 2012 5:54 am

joev wrote:Not a lot of miles yet but this is what I have so far:
428 miles (689km)
79kWh used
80% of the driving is 20-35 mph (32-56 kmph).

Average 5.4miles/kWh (8.7km/kWh)
Average 0.185kWh/mi (0.116kWh/km)
Average 18.46kWh/100mi
Average 11.56kWh/100km


Status quo, all my averages are just about the same as last month.
730 miles (1175km) lifetime
134kWh used lifetime

I am now driving in "B" mode (was driving in "D" and "Eco" in the above stats) and I can see a slight increase in efficiency.
I would not call it a hyper-mile technique but instead of just coasting to a stop I control the braking (slowing the car down) by adjusting the pressure on the accelerator pedal. If I need a greater stopping distance I keep some pressure on the pedal; less stopping distance I ease off the pedal and get more regen.

I keep a monthly and cumulative lifetime average so I will report next month if the "B" mode makes any difference.

JoeS
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Joined: Thu Dec 15, 2011 5:47 am
Location: Silicon Valley, California

Re: Measured Wall-to-Wheels Consumption

Tue Sep 11, 2012 8:19 am

Don wrote:...How far did you compute the car would go at a steady 22 mph Joe? I recall it was something over 400 miles on one charge, wasn't it?
Don, yes, on this thread I had calculated 533 miles at 22mph based on the actual battery current drawn by the controller/motor:
viewtopic.php?p=2857#p2857
I also allowed that even if I was off by a factor of two, three, or even four that going really slowly would still result in a huge "get-home" distance if one had to...
Thinking further about it, what I had only measured was the current going to the motor controller. In addition to this, there's the (not insignificant) current going to the dc-dc converter to run the rest of the car's systems, plus, IIRC, the traction battery supplies some other loads directly as well(?). One of these days we'll have to measure all those loads...

joev, your continued terrific efficiency is a reflection of your hypermiling abilities plus your low average speeds and the flat area that you live in. I'll be interested in seeing how this changes while driving in B. For myself, you'd think I was driving a stick shift as I'm constantly moving through the various modes (including a lot of N) depending on conditions, with many spurts showing that the iMiEV is no slouch. This is counteracted by my wife's featherfooting and consistency.
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

Don
Site Moderator
Posts: 2926
Joined: Thu May 10, 2012 3:55 pm
Location: Biloxi MS

Re: Measured Wall-to-Wheels Consumption

Tue Sep 11, 2012 9:45 am

I have no way (yet) of measuring anything, but I seem to be getting about the same 'mileage' as JoeS - ~4.5 miles per Kwh, only in my case, it's including running the A/C 90% of the time. When I'm fully charged, my RR always reads between 75 and 85 miles, depending on what I did previously. It will be interesting to see here in another couple months what changes when we no longer need the A/C

Mostly flat here (I think that helps a bunch) and other than a 2 mile stretch at 45 mph leaving and coming back home, all speeds are well below that - An average of 30 to 35 I would guess, and we know lower speeds really helps

My worst 'tank' was when we went to another city and back on the freeway - About 65 miles total and I barely made it home . . . . turned off the A/C for the last 20 miles or I don't think I would have. Currently, we have ZERO recharging stations around here, so it's charge at home and that's it

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2017 Chevy Volt Premier
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1979 Honda CBX six into six

JoeS
Site Moderator
Posts: 3802
Joined: Thu Dec 15, 2011 5:47 am
Location: Silicon Valley, California

Re: Measured Wall-to-Wheels Consumption

Wed Sep 19, 2012 2:06 pm

Have now covered over 7300 miles (almost 12000km) and here's the latest actual measured energy consumption from the wall summary since I started keeping track (it's gone up slightly as we've been doing a fair amount of freeway driving lately):

Distance driven with measurements: 6223.8mi (10016.2km)
Energy consumed: 1468.535kWh
Yielding:
Average 4.238miles/kWh (6.821km/kWh)
Average 0.236kWh/mi (0.1466kWh/km)
Average 23.60kWh/100mi
Average 14.66kWh/100km


All the caveats of my 6/15/12 posting apply and I haven't beaten my worst/best records.

My methodology is to keep track of all the energy consumed by the iMiEV on a daily basis, but only incorporate it into my summary spreadsheet after fully charging the car which only occurs every few weeks. Using an iMiEV-dedicated T.E.D (The Energy Detective) sensor and corroborated by Kill-A-Watt (L1) and a kWhr meter (L2). I've recently started keeping track of whether it's L1 or L2 as I was curious what percentage of our charge actually comes from each (eyeballing it, L1 predominates for our everyday overnight charging but L2 is used if recharging during the day is needed).
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

joev
Posts: 53
Joined: Sun Jul 01, 2012 3:07 am
Location: Long Island, NY

Re: Measured Wall-to-Wheels Consumption

Tue Oct 02, 2012 10:11 am

7/31/12
Not a lot of miles yet but this is what I have so far:
428 miles (689km)
79kWh used
80% of the driving is 20-35 mph (32-56 kmph).

Average 5.4miles/kWh (8.7km/kWh)
Average 0.185kWh/mi (0.116kWh/km)
Average 18.46kWh/100mi
Average 11.56kWh/100km

8-31-12
Status quo, all my averages are just about the same as last month.
730 miles (1175km) lifetime
134kWh used lifetime

I am now driving in "B" mode (was driving in "D" and "Eco" in the above stats) and I can see a slight increase in efficiency.
I would not call it a hyper-mile technique but instead of just coasting to a stop I control the braking (slowing the car down) by adjusting the pressure on the accelerator pedal. If I need a greater stopping distance I keep some pressure on the pedal; less stopping distance I ease off the pedal and get more regen.

I keep a monthly and cumulative lifetime average so I will report next month if the "B" mode makes any difference.

9-30-12
And the winner is......B mode. It did make a slight improvment overall.
Averages for the month:
Average 5.7miles/kWh (9.17km/kWh)
Average 0.176kWh/mi (0.109kWh/km)
Average 17.6kWh/100mi
Average 10.9kWh/100km

1303 miles (2097km) lifetime
235kWh used lifetime

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