Page 2 of 7

Re: LEAF Range and kWh use, at 45, 60 and 70 mph DOE tests

Posted: Thu Jun 13, 2013 8:09 am
by RegGuheert
ERG4ALL wrote:The first exhibit states regarding the battery, "Manufacturer: Automotive Energy Supply Corporation". Is that some subsidiary of Nissan? I thought Nissan made its own batteries.
AESC is a joint venture of Nissan and NEC. However, in the US factory, the batteries for the LEAF are manufactured by Nissan, not AESC.

Re: LEAF Range and kWh use, at 45, 60 and 70 mph DOE tests

Posted: Thu Jun 13, 2013 9:45 am
by TonyWilliams
Sublime wrote:
jpa2825 wrote:Can anyone provide an Executive Summary for Dummies? Avg. m/kWh at 45, 60 & 70 mph maybe?
From the battery (from the wall):
45mph = 4.85mi/kWh (3.94mi/kWh)
60mph = 3.70mi/kWh (3.04mi/kWh)
70mph = 2.92mi/kWh (2.48mi/kWh)
That's, of course, different than what we read on the dash. I didn't see if the speed was actual or indicated (big difference).

65mph = 4.0mi/kWh (65 mph indicated on the dash, 62 mph actual)

Re: LEAF Range and kWh use, at 45, 60 and 70 mph DOE tests

Posted: Thu Jun 13, 2013 4:58 pm
by planet4ever
TonyWilliams wrote:
Sublime wrote:From the battery (from the wall):
45mph = 4.85mi/kWh (3.94mi/kWh)
60mph = 3.70mi/kWh (3.04mi/kWh)
70mph = 2.92mi/kWh (2.48mi/kWh)
That's, of course, different than what we read on the dash. I didn't see if the speed was actual or indicated (big difference).

65mph = 4.0mi/kWh (65 mph indicated on the dash, 62 mph actual)
Can you explain that discrepancy, Tony? I would expect only slightly less energy coming out of the battery than goes in, but the apparent mileage gain you show would seem to indicate roughly (1 - 3.7/4.0) = 8.5% loss in the battery, not even allowing for the 2 mph difference you assume. If I interpolate the speeds in the report that becomes a (1 - 3.62/4.0) = 9.5% loss. In our many discussions of charging efficiencies we have, so far as I can remember, treated losses in the battery itself as negligible. But is it really nearly 10%?

Ray

Re: LEAF Range and kWh use, at 45, 60 and 70 mph DOE tests

Posted: Thu Jun 13, 2013 5:38 pm
by DaveinOlyWA
planet4ever wrote:
TonyWilliams wrote:
Sublime wrote:From the battery (from the wall):
45mph = 4.85mi/kWh (3.94mi/kWh)
60mph = 3.70mi/kWh (3.04mi/kWh)
70mph = 2.92mi/kWh (2.48mi/kWh)
That's, of course, different than what we read on the dash. I didn't see if the speed was actual or indicated (big difference).

65mph = 4.0mi/kWh (65 mph indicated on the dash, 62 mph actual)
Can you explain that discrepancy, Tony? I would expect only slightly less energy coming out of the battery than goes in, but the apparent mileage gain you show would seem to indicate roughly (1 - 3.7/4.0) = 8.5% loss in the battery, not even allowing for the 2 mph difference you assume. If I interpolate the speeds in the report that becomes a (1 - 3.62/4.0) = 9.5% loss. In our many discussions of charging efficiencies we have, so far as I can remember, treated losses in the battery itself as negligible. But is it really nearly 10%?

Ray
it probably is negligible if only considering energy from battery to wheels but there is always going to be accessories running that will use power too. notice the faster you go the better the ratio? probably due to less running time, less overhead? dk. if that was the case, how can people drive 150 miles?

Re: LEAF Range and kWh use, at 45, 60 and 70 mph DOE tests

Posted: Thu Jun 13, 2013 6:29 pm
by evnow
edatoakrun wrote:I thought the test results below might be worth a new thread since, AFAIK, these results have not been posted on MNL before, and no reputable test prior to this has correlated range at 45, 60 and 70 mph (constant) with measured kwh use, both DC out of the battery and AC from the EVSE to recharge, as well as charge time for the L2 recharge.

So there are many reference points in these documents for comparison, for any who have used various methods to try to gauge capacity.

http://avt.inel.gov/pdf/fsev/fact2011nissanleaf.pdf" onclick="window.open(this.href);return false;
Excellent - finally we have some numbers from the lab.

What we still don't know is - how the m/kWh that Leaf shows on the dash compares to what they calculated. What Tony and others (including me) have done is to just use Leaf's instrumentation for miles driven and m/kWh.

BTW, the battery roundtrip efficiency is calculated to be between 95% and 98%.

Re: LEAF Range and kWh use, at 45, 60 and 70 mph DOE tests

Posted: Thu Jun 13, 2013 6:49 pm
by planet4ever
DaveinOlyWA wrote:it probably is negligible if only considering energy from battery to wheels but there is always going to be accessories running that will use power too.
So you are claiming that accessories are not included in m/kWh? That is possible, though I think we can say very confidently that climate control is.
DaveinOlyWA wrote:notice the faster you go the better the ratio? probably due to less running time, less overhead? dk. if that was the case, how can people drive 150 miles?
Now that you mention it, that makes no sense at all. The ratio of wall to battery should only depend on how fast you charge, not how fast you drive. But the differences are small enough that perhaps they are only rounding errors.

Ray

Re: LEAF Range and kWh use, at 45, 60 and 70 mph DOE tests

Posted: Thu Jun 13, 2013 8:44 pm
by TonyWilliams
planet4ever wrote:
TonyWilliams wrote:
Sublime wrote:From the battery (from the wall):
45mph = 4.85mi/kWh (3.94mi/kWh)
60mph = 3.70mi/kWh (3.04mi/kWh)
70mph = 2.92mi/kWh (2.48mi/kWh)
That's, of course, different than what we read on the dash. I didn't see if the speed was actual or indicated (big difference).

65mph = 4.0mi/kWh (65 mph indicated on the dash, 62 mph actual)
Can you explain that discrepancy, Tony?
My gut feeling is they have the climate control on. I don't see where it was specified off.

If they did have that off, then I would just argue lab grade equipment versus lowest bidder instruments on the LEAF.

Re: LEAF Range and kWh use, at 45, 60 and 70 mph DOE tests

Posted: Fri Jun 14, 2013 5:27 am
by DaveinOlyWA
planet4ever wrote:
DaveinOlyWA wrote:it probably is negligible if only considering energy from battery to wheels but there is always going to be accessories running that will use power too.
So you are claiming that accessories are not included in m/kWh? That is possible, though I think we can say very confidently that climate control is.
oh they most definitely are included. i have seen my miles/kwh drop when stationary. seeing it once, i would chalk up to the car "adjusting" but have seen it drop at least twice a few times so there is power being consumed enough to make a difference
DaveinOlyWA wrote:notice the faster you go the better the ratio? probably due to less running time, less overhead? dk. if that was the case, how can people drive 150 miles?
Now that you mention it, that makes no sense at all. The ratio of wall to battery should only depend on how fast you charge, not how fast you drive. But the differences are small enough that perhaps they are only rounding errors.

Ray[/quote]

how fast you drive verses how fast you charge? there is real no difference. only the direction the electrons are flowing. so the ratio is better while driving faster only because the duration of the drive is lower so the "somewhat" static overhead the car needs to operate support systems is less of an impact but only because the drive time is lower at higher speeds. But the same overhead experienced when charging is also present while driving right? the pumps that run the water to cool the inverter, etc at least part of the time.

Like Tony, i think there is something missing from the report (since there is very little said about how the test was done) that might be more important than the testers realized?

Re: LEAF Range and kWh use, at 45, 60 and 70 mph DOE tests

Posted: Fri Jun 14, 2013 9:53 am
by TonyWilliams
DaveinOlyWA wrote:Like Tony, i think there is something missing from the report (since there is very little said about how the test was done) that might be more important than the testers realized?
It's a gigantic oversight in the test. Oh well, it's just tax money.

Re: LEAF Range and kWh use, at 45, 60 and 70 mph DOE tests

Posted: Fri Jun 14, 2013 11:19 am
by evnow
DaveinOlyWA wrote:how fast you drive verses how fast you charge? there is real no difference. only the direction the electrons are flowing. so the ratio is better while driving faster only because the duration of the drive is lower so the "somewhat" static overhead the car needs to operate support systems is less of an impact but only because the drive time is lower at higher speeds. But the same overhead experienced when charging is also present while driving right? the pumps that run the water to cool the inverter, etc at least part of the time.
The other thing that can contribute to in/out battery efficiency is the power consumption. Lower power should actually result in lower losses.