Don
Site Moderator
Posts: 2956
Joined: Thu May 10, 2012 3:55 pm
Location: Biloxi MS

Re: i'er iChart: The iMiev Range Chart. ANY VOLUNTEERS?

Fri Jul 04, 2014 3:27 pm

jumpjack wrote:
Don wrote:I didn't read the source data behind the graphs - Do you know if the Peukert Effect was taken into consideration?

Don

Peukert effect is negligible in lithium batteries: discharge them at C20 or C2, and you'll get same capacity.
I agree it's 'negligible' (at least when compared to other chemistries) because lithiums have such low internal resistance, but it's still there and will most certainly have an effect on EV range

Your second graph shows about 4.8 Ah for 1/2C compared to about 4.6 for 4C which is a loss of about 5% over that range. In addition to the wind resistance loss at higher speeds, you can probably tack on another 2 or 3% because of diminishing battery capacity due to Peukert losses

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE Premium, Raspberry Metallic
2012 iMiEV SE, White
2017 Chevy Volt Premier
2014 Ford Transit Connect XLT SWB wagon

GdB
Posts: 154
Joined: Tue Aug 12, 2014 4:06 pm

Re: Speed vs. Power Gauge: Request for Data

Tue Aug 12, 2014 9:19 pm

My EVs: 2012 Mitsubishi i-MiEV and 2019 Hyundai Kona Electric SEL

JoeS
Site Moderator
Posts: 3843
Joined: Thu Dec 15, 2011 5:47 am
Location: Silicon Valley, California

Re: i'er iChart: The iMiev Range Chart. ANY VOLUNTEERS?

Wed Aug 13, 2014 8:12 am

GdB, I took the liberty of moving your post over to this thread. Wow, that wetransfer link is one of the longest I've seen! Thank you for posting. As you noted, the quiescent power draw of the i-MiEV is not included and is actually quite significant with all the car's electronics drawing on the order of a 1/2-kW IIRC, with the car just sitting there turned on and not moving. Your graphs show the dramatic effect that aerodynamic drag has on the vehicle's range, and correlate quite well to the other graphs as well as our practical experience.

Prior to purchasing the i-MiEV, all of us were wondering about its suitability for our daily driving needs in terms of range. After a while, we all come to the realization that Range is whatever we want it to be, and adjust our driving accordingly and, if necessary, pre-plan our en route charging to meet our needs. It really is a non-issue, with the recognition that most of us have an ICE/hybrid available for longer trips, with the i-MiEV satisfying the vast majority of our daily driving needs.
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

GdB
Posts: 154
Joined: Tue Aug 12, 2014 4:06 pm

Re: i'er iChart: The iMiev Range Chart. ANY VOLUNTEERS?

Wed Aug 13, 2014 11:13 am

How was 1/2kW quiescent power measured? Something is not adding up. I put that into my xlsx file and now the 220km record does not match at all.

1/2kW sounds like a lot to me. Where is all that heat going, to do what? The ecu and cooling fans should be much less than 1/2kW.

I assumed a combined motor and battery efficiency of 80% based on this US DOE test report http://avt.inel.gov/pdf/fsev/fact2012mitsubishii-miev.pdf I found. But that may have been the wrong interpretation. Assuming 1/2kW quiescent power, the motor efficiency has to be 92% to match the 220km record. Seems reasonable for these high efficiency rare earth motors, but I am still skeptical of 1/2kW with no lights, A/C, radio...
My EVs: 2012 Mitsubishi i-MiEV and 2019 Hyundai Kona Electric SEL

PV1
Site Moderator
Posts: 3039
Joined: Fri Apr 27, 2012 4:22 pm
Location: Pittsburgh, PA

Re: i'er iChart: The iMiev Range Chart. ANY VOLUNTEERS?

Wed Aug 13, 2014 11:37 am

There are several contactors engaged to provide high voltage power to the car, the DC-DC converter is on, all of the vehicle systems are on, the 12 volt battery is absorbing a charge, and the coolant pump runs every few minutes. CaniOn shows .3 kW being used, and a member left their car on overnight and measured what the car drew to top off the lithium battery. That returned a power load of 146 watts.

.5 kW is a tad on the high side, but not if lights are on. Holding all four power window switches up with all windows up (window motors stalled) will surge draw to 1.2 kW!! 900 watts going to the windows, I don't recommend holding the switch after the window stops for any length of time.
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
"Koorz" - 2012 Cool Silver Metallic ES with QC - 1/5/2015
"Photon" - 2017 Bolt EV LT in Orange with QC - 7/31/2017

Solar-powered since 10/10/2013

JoeS
Site Moderator
Posts: 3843
Joined: Thu Dec 15, 2011 5:47 am
Location: Silicon Valley, California

Re: i'er iChart: The iMiev Range Chart. ANY VOLUNTEERS?

Wed Aug 13, 2014 12:02 pm

I just checked and CaniOn says 0.4kW with the vehicle in READY and Park, but no radio or fan, with climate control OFF, and only the driving lights ON (not headlights). Hmm, wonder if that varies with SOC?

GdB, CaniOn is an Android App that allows viewing a fair number of battery and driving performance-related parameters - since you're a numbers person, I think you would find it very useful. Here's its very lengthy thread on this forum:
http://myimiev.com/forum/viewtopic.php?p=12558#p12558
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

PV1
Site Moderator
Posts: 3039
Joined: Fri Apr 27, 2012 4:22 pm
Location: Pittsburgh, PA

Re: i'er iChart: The iMiev Range Chart. ANY VOLUNTEERS?

Wed Aug 13, 2014 12:31 pm

I think the .4 vs. .3 kW is the driving lights. My measurements are with lights off, radio, and fan off.
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
"Koorz" - 2012 Cool Silver Metallic ES with QC - 1/5/2015
"Photon" - 2017 Bolt EV LT in Orange with QC - 7/31/2017

Solar-powered since 10/10/2013

Return to “Driving the iMiev - Range - Energy Efficiency - Operating Cost”