[TeslaOwner]

Bjørn Nyland has posted a video of consumption test. I assume this car has not had the forthcoming software update which will improve things.

"Test done at 90 km/h, 56 mph. As you can see in the video, the speed was variable due to traffic.
The result was 231 Wh/km, 372 Wh/mi."

 

[phil]

Thanks, TO. Those numbers look poor, and I would not expect there's a great chance of major improvement due to software tweaks at this late date. Most or all useful tweaks should have been completed long ago.

I didn't have time to listen to the whole video - it seemed to go on forever! But I did get the impression Bjorn's testing methodology was subject to a large degree of uncertainty. It will be good to get some more official results, someday.

 

[sciencegeek]

Yeah this seems pretty hokey. Here are a few criticisms for your consideration:

1. He's only doing one test. That's anecdotal. He should perform several tests and use proper statistical analysis to come to a conclusion.

2. He is putting a lot of faith in the estimates of how much battery power remains. Maybe that's off by a bit, which would very much influence the consumption rate he calculates. But to make matters worse, he only went from 75% to 47%, or a quarter of a charge by the car's software's estimate. This is silly.

3. To his credit, he mentions the possibility of measurement error.

4. Overall this is totally stream-of-consciousness, not a proper analysis or presentation of results.

 

[J.XAU]

I'm always surprised by how little information car makers put out from testing prototypes when they have thousands of them racking up millions of miles combined. As potential owners its invaluable it us, its real world testing. Jaguar is at a point they can drop us some hints.

 

[TeslaOwner]

I would not expect there's a great chance of major improvement due to software tweaks at this late date

Tesla took 1s off the 5s 0-60s for the whole fleet (the "cooking version" models) - not exactly a trivial improvement!! - with an over-the-air software update ... so I think "Jag might well do too" and also "Motors on i-Pace are more modern / efficient than Model-S, the CD is only slightly worse, 90-battery reputedly more "usable capacity" than the Tesla S90" - so my prediction is "Ought to be possible"

Dunno how Jag didn't know though ... and if they did big-slap for not saying "Don't worry / we'll fix this" or "Sorry, this is as good as it gets" 'coz Consumers discovering it and announcing it on Social Media is not the best way for these things to come out!

I didn't have time to listen to the whole video - it seemed to go on forever!

Normal for Bjorn. Don't watch any of his Roadtrip videos, nor his Live Streaming

However, his diction is pretty good, I change playback speed to 1.5x (sometimes even 2x) on YouTube (assuming you aren't on some crappy Apple kit that doesn't support that ... sorry a "pet peeve" of mine)

 

[TeslaOwner]

Yeah this seems pretty hokey. Here are a few criticisms for your consideration:

1. He's only doing one test. That's anecdotal. He should perform several tests and use proper statistical analysis to come to a conclusion.

That's all Jag would let him do - a one hour long leg on the multiple EV brand, multiple drivers etc. etc. road-trip "fortum ladetour" tour where Jag only provided one car.

Whilst I agree it is anecdotal, its in line with other people's findings; Bjorn has hundreds (thousands?) of videos on EV related stuff, has driven them in multiple countries across the world, and so on and so on. He gave up his day job to become a full time EV YouTuber - that only says that he has a big following of course, but if his stuff was rubbish, even though he's an engaging guy, I don't think he would be in that position. His insights have often been amongst the first to uncover them (e.g. RapidGate on Leaf)

But, yeah, "just another YouTube channel" ... however most Authentic Journalist reviews I have read are of the "best car I've ever driven" salivating variety, high on First Class Flight and 5-star hotel accommodation & food provided by the vendor. I haven't seen any of those early reviews say anything at all about charging speed or real-world-range, just about the fact that its a nose in front of a Tesla Model-X in a launch-dash - which whilst great for headlines is of no real-world significance at all. And even those were of the one-test-only flavour with no proper statistical rigour or significance.

Still ... my money is on Jag improving this.

 

[phil]

Still ... my money is on Jag improving this.

Mine too, but I think it will improve for the 2020 model year. After years of development, I can't believe they've saved one last giant efficiency improvement for the last few weeks before wide release of the 2019 model.

So long as it gives me ~200 miles to a battery, that's good enough - I won't have any range anxiety. But I would think they can do better than that long term with such a large battery. Ideally, they could someday reduce the battery size while still maintaining 200 miles of real world range.

 

[Pseudonym]

It's my understanding that Jag uses an "unusable" buffer that is twice as big as what Tesla does, so that will have some impact on total range. Once they have more confidence in their tech that might also be something they can reduce via software update.


However, it is also my understanding that Jaguar is advertising that you can charge this car to 100% every day with no worries about battery degradation--unlike a Tesla. I'm sure the larger battery reserve plays into that? I also believe Jaguar uses a more stable battery chemistry that may lend itself to being fully charged better than what Tesla uses for example.

 

[jsimon7777]

The whole "don't charge your battery to full" thing bothers me with Tesla.

 

[TeslaOwner]

The whole "don't charge your battery to full" thing bothers me with Tesla.

Interesting. Can you explain why that bothered you? I've always thought it was "Prolong battery life, charge to 90% for normal use" and then charge to 100% for trips (and don't leave the car parked at 100% for prolonged periods). But there have been stories of people (e.g. taxi companies) who have charged to 100% daily and still had negligible degradation.

If I charge to 100% I don't have full regen, so that's another reason for not doing it daily. But I also don't have full regren on a cold morning (and cold battery), and personally I would like the one-pedal-driving to work the same in all conditions (using friction brakes if necessary) as even after 2 years driving it catches me out for the first 20 minutes/whatever when less than normal

Thinking about it stuff like that might be fine for Early Adopters and Techies, like me, but maybe is unnecessarily complexity for mass-market?

Not sure what the alternative is. If battery [chemistry] can be charged to 100% with no side effects that's obviously great, but seems to me leaving a buffer at the top-end is just costing money having that installed but not available for use.

 

[McRat]

Interesting. Can you explain why that bothered you? I've always thought it was "Prolong battery life, charge to 90% for normal use" and then charge to 100% for trips (and don't leave the car parked at 100% for prolonged periods). But there have been stories of people (e.g. taxi companies) who have charged to 100% daily and still had negligible degradation.

If I charge to 100% I don't have full regen, so that's another reason for not doing it daily. But I also don't have full regren on a cold morning (and cold battery), and personally I would like the one-pedal-driving to work the same in all conditions (using friction brakes if necessary) as even after 2 years driving it catches me out for the first 20 minutes/whatever when less than normal

Thinking about it stuff like that might be fine for Early Adopters and Techies, like me, but maybe is unnecessarily complexity for mass-market?

Not sure what the alternative is. If battery [chemistry] can be charged to 100% with no side effects that's obviously great, but seems to me leaving a buffer at the top-end is just costing money having that installed but not available for use.

Tesla happens to be the King of the Buffer Zone. The 40kWh car had a 60kWh battery in it. Other versions also had de-rated battteries.
But a top and bottom buffer makes for a more useful car, and a longer battery life.

Sure, I can tune a 556HP car engine to 650HP. It is designed with that much overkill. But the engine won't last as long.

 

[phil]

Tesla happens to be the King of the Buffer Zone. The 40kWh car had a 60kWh battery in it. Other versions also had de-rated battteries.
But a top and bottom buffer makes for a more useful car, and a longer battery life.

Sure, I can tune a 556HP car engine to 650HP. It is designed with that much overkill. But the engine won't last as long.

I think Tesla may have been dethroned by Chevrolet in this regard. Both the Bolt and especially the Volt are believed to have enormous buffers, as a percentage of capacity. Not quite so big as the 40kWh Tesla, though...

It does seem to be necessary for current battery technology, I expect the manufacturers generally know what they're doing.

 

[McRat]

I think Tesla may have been dethroned by Chevrolet in this regard. Both the Bolt and especially the Volt are believed to have enormous buffers, as a percentage of capacity. Not quite so big as the 40kWh Tesla, though...

It does seem to be necessary for current battery technology, I expect the manufacturers generally know what they're doing.

The Volt has a 18.4kWh nominal battery with a 14.0 kWh window. This is only 4.4kWh. Percentages aren't the right tool.
I believe the Bolt has a similar sized buffer.
When you consider that miles are based on kWh's available, not percentages, it's kWh's of buffer that is important.
And the i-Pace has 5.3 kWh of buffer according to Jaguar.
Nothing like 5-20kWh of software upgradable buffer seen in some Teslas, but it is not fully usable without paying for the upgrade. You can't fully charge the battery. This applies to 40, some 60's, 70's.

When a Volt is at 0 miles of charge (used all 14.0 kWh), it can still apply full rated HP (161hp actual) even with a 101hp gas generator. Then it will also regen at full charge as well. The buffer is useful.

 

[TeslaOwner]

The Tesla has a "call balancing process" when charging to 100%. The SoC reaches 100% and then the car carries on charging (at tiny kW) and doing its "cell balancing", that can take another 30 minutes or more. I don't know anything about the process / chemistry, other than that it happens. Supposedly this activity also corrects any software drift in range calculation. maybe it also helps any cells that are failing / whatever?

When the 60kWh (software limited 75kWh), top-buffered, battery came out there was talk of how the BMS would cell-balance and, if not, whether absence of that would be an issue, long term.

I dunno the answers ... just posing the question. On other top-balanced cars presumably there is no cell-balancing, or not-in-that-way?

 

[phil]

The Volt has a 18.4kWh nominal battery with a 14.0 kWh window. This is only 4.4kWh. Percentages aren't the right tool.

Well, the right tool depends on the task at hand. For evaluating protection against battery degradation due to undercharging and overcharging, percentage would be a more useful metric than raw kWh. A 4.4kWh buffer provides better protection for a 18kWh battery than it would for a 100kWh battery.

Upselling locked battery capacity is a different question, but sure, in total kWh Tesla cars have far more unused battery capacity than those of any other maker, or perhaps all other makers combined.

 

[McRat]

Well, the right tool depends on the task at hand. For evaluating protection against battery degradation due to undercharging and overcharging, percentage would be a more useful metric than raw kWh. A 4.4kWh buffer provides better protection for a 18kWh battery than it would for a 100kWh battery.

Not really. The 18kWh cycles over 5 times more per 100,000 miles than a 100kWh does.