edatoakrun
Posts: 4757
Joined: Thu Nov 11, 2010 9:33 am
Delivery Date: 15 May 2011
Leaf Number: 2184
Location: Shasta County, North California

Steady State Vehicle Charging Fact Sheet: 2015 Nissan Leaf

Mon Jun 01, 2015 9:45 am

Very interesting report from AVTA on charger efficiency of the 2015 LEAF at variable kW charge rates, with a level of detail beyond previous reports on 2011-13 LEAFs.

Looks like it is intended to help guide grid operators (and maybe, businesses providing multi-vehicle AC charging) manage charge rates between BEVs/PHEVs.

Key Insights from Testing
• Nissan Leaf charging is most efficient and has the best power quality
when charged at the maximum charge rate.
• When charging a 2015 Nissan Leaf, Level 2 charging should be
used instead of Level 1 charging whenever possible. Level 2 charging
is much more efficient than Level 1 charging.
• When reducing the charging of a group of 2015 Nissan Leafs,
the charge rate can be reduced to a point with minimal impact to
charging efficiency and power quality. If it is desirable to reduce the
charge rate below this point, it is better to discontinue the charging
of some vehicles to reach the charge reduction target than to
continue to charge all vehicles at a lower charge rate where both
efficiency and power quality will be negatively impacted...


http://avt.inel.gov/pdf/fsev/SteadyStat ... 15Leaf.pdf

Many AVTA reports on 2011-14 LEAFs available here:

http://avt.inel.gov/fsev.shtml
no condition is permanent

rmay635703
Posts: 420
Joined: Wed Jan 19, 2011 7:43 pm

Re: Steady State Vehicle Charging Fact Sheet: 2015 Nissan Le

Mon Jun 01, 2015 10:22 am

Nothing new, overhead systems on lithium rigs are constant regardless of rate, so the lowest duration charge will have the least overhead.

Its too bad really, my 1981 Comutacar had an overhead of zero while charging and idled at under 25 watts of draw.

By comparison new EVs generally idle at 300 watts plus and their overhead during charging isn't far from there either.

Ah well.

dhanson865
Moderator
Posts: 1477
Joined: Wed May 25, 2011 7:12 am
Leaf Number: 16156
Location: Tennessee

Re: Steady State Vehicle Charging L1 vs L2 3.x KW vs L2 6.x

Mon Jun 01, 2015 10:43 am

http://avt.inel.gov/pdf/fsev/SteadyStat ... 12Leaf.pdf" onclick="window.open(this.href);return false;

It surprised me that L1 120V charging is way more efficient on the 3.6 KW charger than it is on the 6.6 KW charger.

It also appears the sweet spot for L2 charging the 3.3/3.6 KW efficiently is between 8A@240V for 1.9 KW input to 12A@240V for 2.9KW input. If you have 208V instead make it 10A@208V for 2.1KW to 14A@208V for 2.9KW. The power factor at this sweet spot is .98 vs the .99 at full load but I'm thinking the efficiency gain is enough to offset that even if you are billed on apparent power.

L2 on the 6.0/6.6 KW charger is most efficient at full load. Give it a 30+ Amp EVSE and let it pull all it can.


Oh and all the testing was done at 208V. I'm assuming efficiency will improve at 240V and keep the same general shape of the curve but I might be wrong about the exact peak of the curve using that assumption.
2012 Leaf tires 195/65/15 Dunlop Enasave 01 A/S, 15" Rims
wiki/index.php?title=Real_World_Battery_Capacity_Loss
(leaf range chart)
(efficiency 3.x KW vs 6.x KW)
please join Truedelta.com and input your repairs.

User avatar
Nubo
Posts: 4512
Joined: Fri May 28, 2010 11:01 am
Delivery Date: 31 Oct 2014
Location: Vallejo, CA

Re: Steady State Vehicle Charging L1 vs L2 3.x KW vs L2 6.x

Mon Jun 01, 2015 12:20 pm

dhanson865 wrote:Oh and all the testing was done at 208V. I'm assuming efficiency will improve at 240V and keep the same general shape of the curve but I might be wrong about the exact peak of the curve using that assumption.


I'm guessing the study was concerned primarily with accommodation of large public charging sites?
I noticed you're still working with polymers.

edatoakrun
Posts: 4757
Joined: Thu Nov 11, 2010 9:33 am
Delivery Date: 15 May 2011
Leaf Number: 2184
Location: Shasta County, North California

Re: Steady State Vehicle Charging Fact Sheet: 2015 Nissan Le

Mon Jun 01, 2015 12:31 pm

All agree that this study shows that on a 2015 LEAF, increasing the Charge rate from ~3.8 kW to 6.16 kW (maximum tested) only increases efficiency by about 1%, to ~90.5%?

My takeaway from this study (and others) is that a 2013-2015 LEAF with "6 kW" charger does not have a very significant increase in charger efficiency, which seems to confirm results published previously in the 2011 and 2013 Nissan Leaf Advanced Vehicle Testing – Baseline Testing Results-On-Board Charger Efficiency and Overall Trip Efficiency
results.

http://avt.inel.gov/pdf/fsev/fact2011nissanleaf.pdf

http://avt.inel.gov/pdf/fsev/fact2013nissanleaf.pdf

Remember that the results on those tests the term Overall trip efficiency is a misnomer, in the sense in that the calculation depended on the LEAFs own (inaccurate) LBC to determine both "100%" charge SOC and the low SOC point of power reduction.
no condition is permanent

Bob
Posts: 296
Joined: Fri May 24, 2013 7:13 pm
Delivery Date: 30 May 2013
Location: New Hampshire

Re: Steady State Vehicle Charging Fact Sheet: 2015 Nissan Le

Mon Jun 01, 2015 12:35 pm

When charging, something else happens. I think it is cooling pumps. That could be the constant waste of power that is more significant at lower rates than higher rates.

Can anyone confirm this?

Bob

dhanson865
Moderator
Posts: 1477
Joined: Wed May 25, 2011 7:12 am
Leaf Number: 16156
Location: Tennessee

Re: Steady State Vehicle Charging Fact Sheet: 2015 Nissan Le

Mon Jun 01, 2015 2:28 pm

say the overhead waste is 300W max

the efficiency difference of the 3.3 / 3.6 KW on board charger between charging at 3.6KW and 2KW isn't more than 2%.

to compare that if we imagine 2,000 W as 100% efficient and 3.6KW as 98% efficient it is like saying it is 3724W. 3724 / 2400 = 1.55. 300W is 8% of 3724W and 12.5% of 2000W. 12.5/8 = 1.56.

So if I didn't get lost in the math too far the overhead of the charge process gives us a practical wash vs the inefficiency of the charger at full speed for the 3.3 / 3.6 KW charger.

You want to charge faster than the halfway point of 8A at 240V or 10A at 208V to avoid letting the overhead waste dominate but between there and full charging rate the difference in efficacy vs the relative percentage of overhead waste almost negate each other.

If the efficiency difference is less (which it might be) or the overhead waste is more than 300W you'd want to charge as fast as possible even on the 3.3/3.6 KW charger.



On the other hand the 6.0/6.6 KW charger gets more efficient as the percentage of overhead waste decreases amplifying the desire to charge faster. No brainer on those cars to charge as fast as you can.
2012 Leaf tires 195/65/15 Dunlop Enasave 01 A/S, 15" Rims
wiki/index.php?title=Real_World_Battery_Capacity_Loss
(leaf range chart)
(efficiency 3.x KW vs 6.x KW)
please join Truedelta.com and input your repairs.

Moof
Posts: 179
Joined: Sat Sep 06, 2014 5:11 pm
Leaf Number: 004023
Location: Beaverton, OR

Re: Steady State Vehicle Charging Fact Sheet: 2015 Nissan Le

Tue Jun 02, 2015 11:25 am

I know this is a little off topic, but thus far there has been a lot of noise around the Smart Grid, but almost no action I can detect. EV's and EVSE's would be an obvious choice as a starting point (along with home appliances like dryers and AC). So far there is no actual method in place for a grid operator to tell a car it should slow and/or stop charging. Same deal with solar and now these home batteries.
2011 Cayenne Red bought used with 30k miles, manufacture data of 5/2011
42k miles 82% SOH 11 bars 218 GIDs at full charge
Running with Michelin Premier A/S with 42 psi for 10k miles

BrockWI
Posts: 574
Joined: Fri Mar 28, 2014 6:28 am
Delivery Date: 28 Mar 2014
Leaf Number: 423875
Location: Green Bay, WI.
Contact: Website

Re: Steady State Vehicle Charging Fact Sheet: 2015 Nissan Leaf

Tue Aug 18, 2015 12:02 pm

I suspect that charging with 240vac at 6. something uses the least amount of power. Can someone run the numbers of say refilling the Leaf from the wall assuming your putting 20 kwh in the car?

For example
120vac stock evse for x hours consumes x kwh from the wall
240vac 3.3 onboard charger for x hours consumes x kwh from the wall
240vac 6 onboard charger for x hours consumes x kwh from the wall
3 kw solar pv - XW6048 - 8 L16's
4 ton GSHP
2003 VW TDI 170k miles - 52 mpg lifetime
evse level 2 - Clipper Creek HSC-40
2013 S model with QC package Mar of 2013

dhanson865
Moderator
Posts: 1477
Joined: Wed May 25, 2011 7:12 am
Leaf Number: 16156
Location: Tennessee

Re: Steady State Vehicle Charging Fact Sheet: 2015 Nissan Leaf

Fri Dec 11, 2015 9:13 am

BrockWI wrote:I suspect that charging with 240vac at 6. something uses the least amount of power. Can someone run the numbers of say refilling the Leaf from the wall assuming your putting 20 kwh in the car?

For example
120vac stock evse for x hours consumes x kwh from the wall
240vac 3.3 onboard charger for x hours consumes x kwh from the wall
240vac 6 onboard charger for x hours consumes x kwh from the wall


Full charge rate for the 3.6KW charger was around 88.x% (maybe 88.3 or so). Less efficient at full amps

Max efficiency for the 3.6KW charger was around 89.x% (maybe 89.5 or so). But around 12a not 16a.
Max efficiency for the 6.6KW charger was around 90.x% (maybe 90.5 or so). More amps is better on this one.

Max efficiency for the 120V with 3.6KW charger was around 86.x% (closer to 86.25 or so)
Max efficiency for the 120V with 6.6KW charger was around 78% (closer to 77.9% or so)

So you already have enough data in the past tests to know which is better.

Note you need 4 tests not 3. The voltage you charge at isn't the only factor, amps matter as well, and each charger has a different efficiency curve.
2012 Leaf tires 195/65/15 Dunlop Enasave 01 A/S, 15" Rims
wiki/index.php?title=Real_World_Battery_Capacity_Loss
(leaf range chart)
(efficiency 3.x KW vs 6.x KW)
please join Truedelta.com and input your repairs.

Return to “Batteries & Charging”