GetOffYourGas
Posts: 1687
Joined: Tue Dec 20, 2011 6:56 pm
Delivery Date: 09 Mar 2012
Location: Syracuse, NY

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

Wed Jul 12, 2017 10:42 am

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


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

EV Fleet:
2011 Torqeedo Travel 1003 electric outboard on a 22' sailboat
2012 Leaf SV (traded for Bolt)
2015 C-Max Energi (302A package)
2017 Bolt Premier

edatoakrun
Posts: 4748
Joined: Thu Nov 11, 2010 9:33 am
Delivery Date: 15 May 2011
Leaf Number: 2184
Location: Shasta County, North California

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

Wed Jul 12, 2017 10:51 am

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.
no condition is permanent

NeilBlanchard
Posts: 605
Joined: Sat Oct 11, 2014 5:02 pm
Delivery Date: 14 Oct 2014
Leaf Number: 306278

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

Wed Jul 12, 2017 12:48 pm

NavyCuda wrote: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...


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.

DaveinOlyWA
Posts: 12313
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 10 Nov 2016
Leaf Number: 314199
Location: Olympia, WA
Contact: Website

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

Wed Jul 12, 2017 2:28 pm

2011 SL; 44,598 miles. 2013 S; 44,840 miles.2016 S30 (build 10/2016)"low water marks" 27,000 miles.363GID Ahr 79.13Hx95.17%kwh28.1QCs238,L2's 251
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

lorenfb
Posts: 1405
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

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

Wed Jul 12, 2017 2:40 pm

NeilBlanchard wrote:
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%.


Link/reference, please.

GRA
Posts: 7555
Joined: Mon Sep 19, 2011 1:49 pm
Location: East side of San Francisco Bay

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

Wed Jul 12, 2017 5:22 pm

lorenfb wrote:
NeilBlanchard wrote:
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%.


Link/reference, please.

This one, I imagine, although it's a concept rather than a product:
Better electric motors can boost electric-car efficiency
http://www.greencarreports.com/news/111 ... efficiency
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

NeilBlanchard
Posts: 605
Joined: Sat Oct 11, 2014 5:02 pm
Delivery Date: 14 Oct 2014
Leaf Number: 306278

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

Thu Jul 13, 2017 12:03 pm

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

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OrientExpress
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Leaf Number: 2331
Location: San Jose, Ca

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

Thu Jul 13, 2017 12:25 pm

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.
2014 LEAF SV
Ocean Blue
Delivery May 23 2014
46,000+ miles - all 12 bars - Same range as new - No warranty issues ever!

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OrientExpress
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Leaf Number: 2331
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LEAF Advisory Board and the new LEAF

Thu Jul 13, 2017 3:48 pm

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
2014 LEAF SV
Ocean Blue
Delivery May 23 2014
46,000+ miles - all 12 bars - Same range as new - No warranty issues ever!

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DNAinaGoodWay
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Joined: Mon Dec 17, 2012 1:43 am
Delivery Date: 03 Dec 2012
Leaf Number: 23156
Location: Central Massachusetts

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

Thu Jul 13, 2017 5:13 pm

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


great shots of test mule up close.


My favorites:

IMG_6742.JPG


IMG_6740.JPG
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'12 SL last reading @ 2 yr, 22k, 260 GIDs, 62.35 Ahr

'15 SV w/QC, Mfd 5/14, Leased 8/14, 292 GIDs, 64.38 Ahr when new
@ 36 months, 34k, 270 GID, 57.49 Ahr

'17 Bolt LT



6.72 kW Array

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