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

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I'd be happy to apply my graphic design skills to create such a chart (or perhaps one Tufte could like a little more).

But, where does the data come from? Reported driving runs? Actually energy usage calcs? Something interpolated in between? Get me the data -- I'll draw you the chart.
 
MtnViewMark,
Here's the data (version 5)


iChart:iMiev Range in MILES v5 – John Annen
MPH . . . 35 40 45 50 55 60 65 70 75
BARS %
16 100 100 90 83 73 67 62 56 52 47
15 . 94 . 94 84 76 67 61 56 50 46 41
14 . 87 . 87 72 71 62 57 52 57 43 39
13 . 81 . 81 72 66 59 53 49 44 41 36
12 . 72 . 72 64 58 51 57 43 39 36 33
11 . 66 . 66 58 53 47 43 40 36 34 31
10 . 60 . 60 52 47 41 38 34 30 28 27
..9 . 56 . 56 49 44 39 36 33 29 26 24
..8 . 50 . 50 47 41 37 35 31 27 24 21
..7 . 44 . 44 37 33 29 26 24 21 20 18
..6 . 37 . 37 31 27 23 21 19 17 15 14
..5 . 31 . 31 26 22 18 16 14 12 11 10
..4 . 25 . 25 21 18 15 14 13 14 12 . 9
..3 . 19 . 18 18 15 14 13 12 10 . 9 . 7
..2 . 12 . 12 12 10 . 9 . 9 . 8 . 7 . 6 . 5
..1 . .6 . . 6. . 6 . 5 . 5 . 4 . 4 . 4 . 3 . 3


1. Subtract one Bar for each 20 minutes of A/C.
2. Subtract one Bar for each 40 minutes of heat.
3. The range below Bar 1 is reduced by battery cell imbalances. The i needs
to be charged to 100% to rebalance the cells. The REBALANCE is most
important after several less than 100% charges. The i can go 6 miles in
turtle mode if the cells are balanced. Don't count on it.
4. Add One mile at 60mph for every 15 min. charge on 120V 8A iCharger
5. Add One mile at 60mph for every 5 minutes of 240V, 16amp charger
6. Wind speed is more important than ground speed for calculating range.
50mph with 10mph headwind equals 60mph range in the iChart.
7. Add 1% to range for each 4° F above 70° F
8. Subtract 1% in range for each 2°F below 70° F
9. Subtract 2% in range for every 10,000 miles for Battery Degradation.
10. Increase range 1.5% per 1000 ft/300m for air density above sea level
11. Heavy loads get less range than light loads.
12. Wind load goes up as the third power of wind speed. Twice the
speed (mph) creates 8x the wind resistance.
13. Rain decreases range.

The formatting looks better with version 5 at:

http://www.facebook.com/media/set/?set=a.2790482153603.2125305.1004832596&type=1&l=51a8b1aa1f
I am still try to make the table more accurate.

-- John Annen
 
Wee John said:
These numbers are with no heater or AC, right? If so, I would say they are pretty accurate with my driving experience so far.
Wee John,
You are correct. Give me some of your data, and I will adjust the iChart. Here are a few other adjustments.
1. Subtract one Bar for each 20 minutes of A/C. Wee John, What's your data?
2. Subtract one Bar for each 40 minutes of heat.
3. The range below Bar 1 is reduced by battery cell imbalances. The i needs to be charged to 100% to rebalance the cells. The REBALANCE is most important after several less than 100% charges. The i can go 6 miles in turtle mode if the cells are balanced. Don't count on it.
4. Add One mile of range @ 60mph for every 15 minute charge at 120 volt 8 amp iCharger
5. Add One mile of range @ 60mph for every 5 minutes of charge at 240 volt/16amp w/3.3kW charger
6. Wind speed is more important than ground speed for calculating range. 50mph with 10mph headwind equals 60mph range in the iChart.
7. Add 1% to range for each 4° F above 70° F
8. Subtract 1% in range for each 2°F below 70° F
9. Subtract 2% in range for every 10,000 miles for Battery Degradation.
10. Increase range 1.5% per 1000 ft/300m for air density above sea level
11. Heavy loads get less range than light loads.
12. Wind load goes up as the third power of wind speed. Twice the speed (mph) creates 8x the wind resistance.
13. Rain reduces range.

Latest version4:
http://www.facebook.com/media/set/?set=a.2790482153603.2125305.1004832596&type=1&l=51a8b1aa1f
 
Here is 3 months of actual real world range of the I Miev. Does it match the range chart? It match the 62 US(EPA) average
http://evdrive.wordpress.com/2012/02/07/the-return/
 
markbb99 said:
Does it match the range chart?
evcharge.png

markbb99,
Great data. Thanks. My iChart seems worst than optimistic. I need an iChart version 5 DO-OVER. Sorry

Does your graph include a third of your driving above 50mph? (I am guessing No.)
From your text very little accessory use. Headlamps? Rain? Snow?
Maybe temperature is biggest difference. The iChart is for 70°F. If your car was at 0°F, the 70°F difference indicates a 35% reduction in range.
At low speeds the heater can also make up to a 30% derating of range. I am assuming the heater draws ~ 1.5 kW peak. ( Not for your graph though.)

Anybody else have data to share?
 
I'd just like to say that the charging data above is from my blog.
I've had the use of an i-MiEV for 3 months won in a competition through the UK energy provider E.ON.

To answer questions on usage I'd say only a small amount was done over 50 mph, mainly as the conditions didn't allow and I was aware that above this the battery drained a lot more quickly.
The conditions were across a British Winter with some freezing days and a lot of wet days. So temperatures from -5C to 10C. I didn't venture out in the snow as I was concerned about possible damage on the ice. I avoided using the heater apart from to defrost the car when first setting off. Hope this helps.
 
JohnQ - thank you for diligently keeping track of your usage and posting this information. I've just received my iMiEV and have already started keeping track of my input energy and usage. Your data was taken in conditions significantly cooler than what we experience here in California (not in mountains - where our winters are a skier's haven), so I would expect our performance to be better; however, your minimal use of the motorway/freeway gives you the efficiency advantage, as the iMiEV's relatively poor aerodynamics exacts a significant penalty at those speeds. Time will tell…

FiddlerJohn, I'm still grappling with the underlying assumptions (and their source) for each of the variables which goes into the Leaf and your charts. For the time being, I'm taking the empirical approach… for example, my wife (a featherfoot) took the car to town yesterday, leaving with 15 bars and a RangeRemaining of 58 miles. She drove 16.3 miles, and came back with 13 bars and RR of 57 miles. I think my iMiEV is still trying to figure out her driving style… :roll:
 
John, thanks for such detail. Can you point to any more detail on the balancing method or hardware? In looking at range extension options, I've zeroed in on the HVDC charger output, which appears to be a quick disconnect.
Pictured http://www.caranddriver.com/photos-10q1/335484/mitsubishi-i-miev-on-board-charger-photo-335603
That may be a place to add in a pigtail for 330V input/output (no more than 10A at first, to match charger output). If a supplemental 330VDC source were plugged in there, it could be disconnected often to allow the OEM pack balancing process, and this method may not actually require any permanent modifications to the car.
 
jray3 said:
... Can you point to any more detail on the balancing method or hardware? ... charger output, which appears to be a quick disconnect. Pictured ...
jray3, I like your ideas. Your question was the inspiration for the post: "BMU,Cautions,CMU, SERVICE PLUG, BALANCER,CAN, K-Line."

Here is a better display of the iChart:

1-ichart-imiev-range-miles-v5-john-annen.png


I'm still not happy with this iChart. After a get my iMiEV, I will be able to do a little better. The approximation that TWICE THE SPEED WILL HALVE THE RANGE is a good rule of thumb.
 
Code:
iChart:iMiev Range in MILES v5 – John Annen
MPH        35  40  45  50  55  60  65  70  75
BARS   %                                     
16   100  100  90  83  73  67  62  56  52  47
15    94   94  84  76  67  61  56  50  46  41
14    87   87  72  71  62  57  52  57  43  39
13    81   81  72  66  59  53  49  44  41  36
12    72   72  64  58  51  57  43  39  36  33
11    66   66  58  53  47  43  40  36  34  31
10    60   60  52  47  41  38  34  30  28  27
 9     56   56  49  44  39  36  33  29  26  24
 8     50   50  47  41  37  35  31  27  24  21
 7     44   44  37  33  29  26  24  21  20  18
 6     37   37  31  27  23  21  19  17  15  14
 5     31   31  26  22  18  16  14  12  11  10
 4     25   25  21  18  15  14  13  14  12   9
 3     19   18  18  15  14  13  12  10   9   7
 2     12   12  12  10   9   9   8   7   6   5
 1      6    6   6   5   5   4   4   4   3   3
Reformatted the chart so it's readable here on the forum.

How accurate is this chart in people's real-life experience?
 
drees, thank you for reformatting John's chart and posting it here so we can all easily read it.

Sure, aerodynamics (and thus speed) plays a major role. Disregarding all the other significant variables (HVAC, altitude change, head/tailwinds, ambient temperature), this chart is probably a pretty good start for those who worry about that sort of thing. For myself, I only looked at the top row and said "yeah, that's about right", and ignored all the rest.

Range is of foremost concern prior to purchase and early-on in EV ownership. After a few weeks it becomes a non-issue. We drive the car normally, reflexively adjusting our driving and HVAC settings and charging regimen to arrive at our destination (where we can charge) with a comfortable distance and time cushion remaining.

For highway trips over about 50-60 miles or without guaranteed charging at the destination or that are time-constrained, I simply take the hybrid.

Not worth anyone's time picking the nits, IMO. ;)
 
JoeS said:
For highway trips over about 50-60 miles or without guaranteed charging at the destination or that are time-constrained, I simply take the hybrid.

Not worth anyone's time picking the nits, IMO. ;)
For sure - the top line is the one I'm most interested in. My parents just picked up an iMiEV (I've had a LEAF for nearly 2 years now so am very familiar with it's capabilities), so I'm trying to figure out what's possible at various speeds.

For example, I know that in my LEAF doing mostly 65 mph on the freeway with a bit of surface streets mixed in, 70 miles is about as far as I want to push it without some recharging on a 100% charge (obviously have some backup plans). On a 80% charge, 50 miles is about the limit - in both cases, this leaves about 10 miles of buffer for "just in case" scenarios. On the LEAF at least, A/C usage is negligible on the freeway unless it's over 90F.

So assuming I want to leave 10 miles of buffer and I have a 50 mile trip, it looks like I would want to limit speeds to 65 mph max and really aim for a few MPH slower than that. Good starting point?
 
dees, delighted that you are now a two-EV family!
drees said:
So assuming I want to leave 10 miles of buffer and I have a 50 mile trip, it looks like I would want to limit speeds to 65 mph max and really aim for a few MPH slower than that. Good starting point?
Right On!

Good comparison that the fully-charged iMiEV has roughly the same range as an 80%-charged Leaf (2010-2012). It's all in the ballpark, as an individual driver's hypermiling abilities are the primary contributors to any differences. With our ability to quickly pop her into N and better control over regen than the Leaf, I find hypermiling easier and more satisfying in the iMiEV than the Leaf.

Our heater is by far the biggest range-robber after speed. Aircon and all the other electrical accessories (including the seat heater) are negligible in comparison.

Note that for battery longevity some of us rarely drop below four bars nor charge above about 13 bars. I only fully-charge just before setting off on a longer trip.
 
Remember that the i-MiEV's aerodynamics have a big part in this. I made a 72 mile highway trip by following (safely) behind a large truck at 60MPH. A 120V charge was done at the mid point, but I could have made it without the charge. Barely. Probably would've met Mr. Turtle for the first time.
 
Neither of the above graphs makes any sense to me

The red line crosses 100 miles of range at about 47.5 mph and 50 miles of range at about 77.5 mph - Neither are possible

The blue power line crosses 5KWH of energy usage at about 40 mph, which would make it seem like you could go more than 120 miles (on 15KWH) at 40 mph and that's not possible either

I can't find anything on that graph which seems do-able

Don
 
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