LEAF 2 : What we know so far (2018 or later?)

NavyCuda said:

Though if they really wanted to chase efficiency they'd go back to drum brakes...

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Please don't give them too many ideas. I don't want a heavy EV that relies on the stopping power of drum brakes.

Other than aero improvement to reduce drag, I expect the two most significant efficiency improvement we are most likely to see from Gen One to Gen Two are in braking and energy cycling/pack thermal management.

Gen one leaf Braking (despite improvements from MY 2013) requires far to much friction braking, and has been improved on by most all other BEVs that followed it, which were able to increase the regen fraction of deceleration.

Once battery temperature reaches optimum, probably somewhere between 90 f and 100 f, there is no benefit to the additional heat generated in the pack during charging or discharging.

Gen one LEAF's passive thermal battery management was designed to divert more charge (both from the ports and from regen) and discharge energy to battery heating when the pack is cold than when it is warm, but I expect the gen two packs will be improved to reduce the wasted energy (and deleterious effects on battery longevity) from over-heating the packs, after optimum temperature is reached.

NavyCuda said:

I don't think there is much more room for efficiency gains in the motor itself. Electric motors have been around for over a century and the behavior of electricity is much more predictable than a combustion event.

On the Battery management and inverter side I don't think we'll see much more either.

I am surprised however that Nissan didn't use a planetary gearset for the gear reduction, as planetary gearsets have the least parasitic losses.

Though if they really wanted to chase efficiency they'd go back to drum brakes...

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Recently, someone reported on a improved motor design that increased the efficiency by about 4.4% - which is a lot considering it was already probably at about 92-94%.

Typical EV's lose about 15% plug to wheel, and better EV's lose about 8%, so that is significant.

Aerodynamic improvements could be the biggest leap in range; but lower loss drivetrain would be good too.

https://www.facebook.com/groups/nissan.leaf.owners.group/permalink/1552608654809970/


great shots of test mule up close.

NeilBlanchard said:

Recently, someone reported on a improved motor design that increased the efficiency by about 4.4% - which is a lot considering it was already probably at about 92-94%.

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Link/reference, please.

lorenfb said:

NeilBlanchard said:

Recently, someone reported on a improved motor design that increased the efficiency by about 4.4% - which is a lot considering it was already probably at about 92-94%.

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Link/reference, please.

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This one, I imagine, although it's a concept rather than a product:

Better electric motors can boost electric-car efficiency

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http://www.greencarreports.com/news/1111340_better-electric-motors-can-boost-electric-car-efficiency

We know the best electric motors are 98.5% efficient - the hub motors used on the Stella solar racer, in particular.

The efficiency number that I look for is the miles per kWh. On average every BEV out there today is in the 4.5 mile/kWh range, from Nissan to Tesla. Of course, there will always be Hypermilers that get significantly better mileage, but on average the number is in the 4~4.5 mile range.

I'm wondering if anyone has a list of the original LEAF Advisory Board members that they could share with me? You can PM me if you want.

Thanks

DaveinOlyWA said:

https://www.facebook.com/groups/nissan.leaf.owners.group/permalink/1552608654809970/


great shots of test mule up close.

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My favorites:

Those two pics are pretty good. Anyone have access to the Facebook group to post more pics here? I seem to not be able to see any of them or have no way to "join" that group.

OrientExpress said:

The efficiency number that I look for is the miles per kWh. On average every BEV out there today is in the 4.5 mile/kWh range, from Nissan to Tesla. Of course, there will always be Hypermilers that get significantly better mileage, but on average the number is in the 4~4.5 mile range.

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You must not spend much time on the Tesla forums (teslamotorsclub.com). They talk about (333 wh/m) 3 miles per kWh like it's good efficiency. You talk to them about (250 wh/m) 4 miles per kWh and they'll look at you like you are crazy.

I'll be disappointed if the Gen Two LEAF can't at least come close to matching the Ioniq's efficiency, which is impressive in near-ideal conditions:

This may not exactly be real world, but...
Last Sunday someone from Germany drove in his Ioniq EV all day and set a record range of 400 km (249 miles)!
Efficiency was 6.6 kWh/100km or 15.2 km/kWh (10.6 kWh/100mi or 9.4 mi/kWh).

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https://speakev.com/threads/real-world-range-of-ioniq-ev.28633/page-4

Original report:

http://www.goingelectric.de/forum/hyundai-ioniq-batterie-reichweite/hypermiling-howto-t23775-140.html

DNAinaGoodWay said:

My favorites:

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Wow, those are great photos. I hadn't seen them before, thanks for sharing!

I hadn't seen the chargeport open like that before. I was under the impression that it was still the lower part of the "grill" that opened. I guess not. I'm glad they are keeping the connectors up front. IMO, that's the best place for them.

jdcbomb said:

Those two pics are pretty good. Anyone have access to the Facebook group to post more pics here? I seem to not be able to see any of them or have no way to "join" that group.

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Easy to join. Click the join button on the group's page and a very short time later someone accepts you.

Here's another:

Reddy said:

http://insideevs.com/new-2018-nissan-leaf-caught-in-public-spyshots/

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Very interesting, if correct:

...Based on the charging stats, I believe the car has a 50-60 kWh battery. As a side note, the gen2 car seems rather large compared to the gen1 car, I believe the wheelbase is about 10-12" longer...

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I find both of those hard to believe, unless the test car is testing the 60kwh pack that will be available next year. That would make sense.

dhanson865 said:

You must not spend much time on the Tesla forums (teslamotorsclub.com). They talk about (333 wh/m) 3 miles per kWh like it's good efficiency. You talk to them about (250 wh/m) 4 miles per kWh and they'll look at you like you are crazy.

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The Model S is a big car; it's not surprising that 400 Wh/mi is considered "average". When I first got ours, that's about what I was getting. Now that I've grown into the car I regularly get under 300 Wh/mi for local driving. What's funny is that when use it for commuting (once a week or so), I get 250 Wh/mi (4 mi/kWH) on the way home, which is just a bit worse than the 4.3 mi/kWh (233 Wh/mi) what I get in the LEAF (which I commute in the rest of the time).

I also saw a test mule charging in Tacoma and I was surprised that the car does appear to be longer than my LEAF. If I had to guess, maybe 6-10" or so? Guessing this means more rear leg room and larger cargo space. I guess reclining rear seats like the Prius V might be nice as well