Reported energy consumption [kWh/100miles] is utterly completely totally wrong - Page 4 - Jaguar I-Pace EV400 Forum
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post #31 of 57 (permalink) Old 08-25-2019, 09:25 PM Thread Starter
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Quick update. Depleting the battery from reported SoC of 100% to 7% used 74.5 kWh in 160 miles. JLR's per trip consumption figure implied 50.9 kWh for that distance. Crazy!

I'll keep gathering the same type of data while I'm still on 14.2 and 18D. At some point in the future I'll get the updates (when the dust has settled) and repeat to see if they fixed that issue.
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post #32 of 57 (permalink) Old 08-25-2019, 10:45 PM
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Here's a preview of actual consumption calculation based on battery SoC in kWh reported by the API and made accessible by WattCat.

Prepare to be shocked.

Mostly suburban driving, fairly aggressive because I have zero patience in traffic and make full use of high-regen one pedal driving. A little bit of freeway.

Regardless of driving style, it's crazy and in fact embarrassing that the JLR computation off by this much.

I will keep posting on this until JLR figures this out.
The I-Pace/InControl error factor must be influenced by the driving type (spirited, normal, hypermiling, etc.) and location (city, highway, rural). The I-Pace reported consumption was in error by 22% after a full day of city driving. Today's drive was round trip to Denver on state highways driving conservatively and the error fell to only 7.7%. The drive included 1800 ft of elevation change in each direction and the use of AC on the return trip. Overall, driving like I have grandkids in the back yields fairly accurate numbers from the car. Short trip on rural roads to drop our son and grandkids home yielded a small error of 2.2%. I will try Sciencegeek's idea of driving aggressively for awhile to see the effect. Not that it will be fun... but simply for science. Yep, sure.
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post #33 of 57 (permalink) Old 09-02-2019, 08:16 PM
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Hello I-Pace drivers,

I am new to EV's and am only now trying to get a better grasp on my I-Paces performance. I won't say that JLR is write or wrong in their calculations but I will say that I am a bit perplexed by it all. Let me share some numbers with you.

I did a trip today and the temperature was about 22 celsius.

At the beginning of my trip the battery was charged to 85% and the available range was 273KM (Yes I am working with the metric system),

I drove 163 km at an average speed of 84 km/hr. The terrain was very hilly with some steep climbs and descents.

During the trip I regenerated 3.3KWH.

At the end of my trip my available range was down to 74 km and my batter charge was 26%.

According to JLR's calculations my Kwh/100 KM was 28.3

Therefore I should have consumed 45 Kwh to travel the 163 KM.

Now this is where I get concerned.

If the battery gives me 90 Kwh of available power and I consumed 59% of the available charge (85% start - 26% at end) that means that I actually used 53.1Kwh thats a difference of 18% which is massive.

If as some suggested in a previous thread that the available charge was about 84KwH than the numbers change as follows. Actual use 49 Kwh which a difference of 10.8%.

Am I missing something important? The thing that really bothers me is the average consumption calculated by JLR vs what I think are the actual numbers. What numbers can I trust from the I-Pace's systems?
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post #34 of 57 (permalink) Old 09-02-2019, 09:21 PM
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Originally Posted by ThinAir View Post
Hello I-Pace drivers,

I am new to EV's and am only now trying to get a better grasp on my I-Paces performance. I won't say that JLR is write or wrong in their calculations but I will say that I am a bit perplexed by it all. Let me share some numbers with you.

I did a trip today and the temperature was about 22 celsius.

At the beginning of my trip the battery was charged to 85% and the available range was 273KM (Yes I am working with the metric system),

I drove 163 km at an average speed of 84 km/hr. The terrain was very hilly with some steep climbs and descents.

During the trip I regenerated 3.3KWH.

At the end of my trip my available range was down to 74 km and my batter charge was 26%.

According to JLR's calculations my Kwh/100 KM was 28.3

Therefore I should have consumed 45 Kwh to travel the 163 KM.

Now this is where I get concerned.

If the battery gives me 90 Kwh of available power and I consumed 59% of the available charge (85% start - 26% at end) that means that I actually used 53.1Kwh thats a difference of 18% which is massive.

If as some suggested in a previous thread that the available charge was about 84KwH than the numbers change as follows. Actual use 49 Kwh which a difference of 10.8%.

Am I missing something important? The thing that really bothers me is the average consumption calculated by JLR vs what I think are the actual numbers. What numbers can I trust from the I-Pace's systems?
Welcome to the forum, ThinAir! I'm glad you discovered the discrepancy between Jaguar/I-Pace energy used versus actual consumption early in your ownership. Understanding this phenomenon will keep you from being stranded at some point. No one on the forum has adequately explained why the I-Pace underestimates energy consumed but this does happen. Some of us on the forum are using an app called WattCat developed by a Norwegian I-Pace owner. The app mirrors some of the capability of InControl with a few major differences. WattCat provides the available kwH in the battery. This has allowed us to measure the difference between I-Pace reported and WattCat real-world consumption. I have experienced an error factor of about 15% in city driving and 8% in highway driving. This may not seem too much until you factor in range prediction error which is about 35 miles per 100% state of charge. Sciencegeek has experienced an average error of 43% in mostly city driving and driving more aggressively than I do.

I think it's great that you measured your energy usage and did the math to compare your experience with the I-Pace numbers. Most people trust the car which can lead to disaster on a long trip. It's funny that WattCat draws the same available kWh that InControl has access to and I can't understand why the I-Pace is off by so much.

Again, welcome to the forum!
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post #35 of 57 (permalink) Old 09-03-2019, 02:27 PM
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Ok. You guys are freakin me out. I'm soon to take my first trip out of town. My destination is 105 miles from my house (very uphill there, and very downhill back). I'm planning to make use of an EA fast charger in a Walmart 38 miles from my house, but directly on the way (home). So, I would need to make it 105 + 105 - 38 = 172 miles.

My own range calculations using the InControl Journey downloads only Efficiency numbers to compute KWh used, indicate that my Highway driving in hot (Phoenix) conditions should give me 212 miles. Should I be worried that the KWh used I calculate using the numbers from Jaguar are not believable? - Enough to be off by the 40 miles I need?

Last edited by WattAJag; 09-03-2019 at 02:33 PM.
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post #36 of 57 (permalink) Old 09-03-2019, 02:42 PM Thread Starter
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Ok. You guys are freakin me out. I'm soon to take my first trip out of town. My destination is 105 miles from my house (very uphill there, and very downhill back). I'm planning to make use of an EA fast charger in a Walmart 38 miles from my house, but directly on the way (home). So, I would need to make it 105 + 105 - 38 = 172 miles.

My own range calculations using the InControl Journey downloads only Efficiency numbers to compute KWh used, indicate that my Highway driving in hot (Phoenix) conditions should give me 212 miles. Should I be worried that the KWh used I calculate using the numbers from Jaguar are not believable? - Enough to be off by the 40 miles I need?
How many feet of climbing?
Your driving style will make all the difference. If you take it fairly easy you should be fine.
Also: just take the trickle charger and plug it in overnight (if possible .. and if there isn't another charging option at the destination)

[My GoM consistently overestimates my range by at least 25% and I have about the same GoM range as you, so based on my personal experience yes you are in the danger zone; but others here have used Eco mode with good results, so maybe just do that and hope for the best. Pack the trickle charger regardless.]
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post #37 of 57 (permalink) Old 09-03-2019, 02:55 PM
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Posted this elsewhere, maybe it'll reassure?

I took a 170-ish mile round trip this weekend, in the 90 degree heat and a little uphill one way, downhill the other (in the NC foothills). 4 people, eco mode, AC on the whole way, 65-75 mph the whole way. Made it home with about 23% battery, which gives an estimated total range under those conditions of just under 220 miles. So if you're going to hit up a charger on the way back I think you'll be fine.
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post #38 of 57 (permalink) Old 09-03-2019, 03:27 PM
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I am going and coming back in the same day. JTDavi3 makes me feel better. My usual ECO score is in the high 90's. It will be over 90 degrees going and 100 degrees coming back (I expect), so the A/C will be on - no choice. Only me in the car. Going up 4000 feet in elevation - and coming back the same route.

I'm going to make a shorter highway run in the same conditions uphill and back down. And, compute my Miles/Battery % up and back (which I know isn't useful to compare against another car, but is probably the most useful number to know). That will probably tell me what I need.
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post #39 of 57 (permalink) Old 09-03-2019, 04:18 PM
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Originally Posted by WattAJag View Post
I am going and coming back in the same day. JTDavi3 makes me feel better. My usual ECO score is in the high 90's. It will be over 90 degrees going and 100 degrees coming back (I expect), so the A/C will be on - no choice. Only me in the car. Going up 4000 feet in elevation - and coming back the same route.

I'm going to make a shorter highway run in the same conditions uphill and back down. And, compute my Miles/Battery % up and back (which I know isn't useful to compare against another car, but is probably the most useful number to know). That will probably tell me what I need.
The 4,000ft elevation gain has me worried especially while running the AC. You will make it to your 1st stop but getting back to the charging station will be dicey even with the elevation loss. You might consider charging to 100% on the first leg. It is more time consuming and expensive but should get you back to the station on your return trip and you may not need to stop at all. Charging on the way up will put you at 100% SoC with the climbing leg at 78 miles and then mostly downhill from there.

Anyone else recommend this?
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post #40 of 57 (permalink) Old 09-03-2019, 04:48 PM
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The 4,000ft elevation gain has me worried especially while running the AC. You will make it to your 1st stop but getting back to the charging station will be dicey even with the elevation loss. You might consider charging to 100% on the first leg. It is more time consuming and expensive but should get you back to the station on your return trip and you may not need to stop at all. Charging on the way up will put you at 100% SoC with the climbing leg at 78 miles and then mostly downhill from there.

Anyone else recommend this?
I think this sounds like a great idea, just to be safe.
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