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Reliable EV Data for Comparison

Posted: Tue May 11, 2010 11:28 pm
by AndyH
This data will give us a quick and easy 'master key' to understanding Leaf test results and other tech data and help us get a better 'feel' for our user experience.

This page gives a standard 1-page summary of 22 factory electric vehicles - cars and trucks - using lead, NiMH, and lithium batteries.

Also listed are vehicle reliability reports and DOE/Southern California Edison testing.

EVAmerica Test Results and much more from the Idaho National Lab's Full Size EV test page

The INL link also includes test procedures and results of US Postal Service tests.

Altra! Re: Reliable EV Data for Comparison

Posted: Wed May 12, 2010 12:56 am
by AndyH
All righty then - let the fun begin. Folks are wondering about how far the Leaf will move on a charge.

We have a starting point - the standardized test cycle range of 'at least' 100 miles on the LA4 (UDDS) drive cycle. But how far can we drive at 45mph or at 65mph? We don't know yet. But we can develop an educated guess.

J1634 used the same test cycle Nissan reports - the LA4 or UDDS. This data is pulled directly from the EVAmerica test results and is sorted by LA4 test cycle range.

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Battery types:
PbA: Lead acid
NiMH: Nickel metal hydride
LiMn: Lithium Manganese

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This graphic shows results from Southern California road testing on the DOE's 'Pomona Loop'. Details at the link. Notice the range - and 'range of range' from the only lithium powered car in the lineup? :D Lithium is a 'game changer' in more than just charging efficiency!

Re: Reliable EV Data for Comparison

Posted: Wed May 12, 2010 6:02 am
by sjfotos
Thanks Andy, That is a really informative chart. The one thing that is tells me is that the range of the Leaf is not a quantum leap in the range of past vehicles. This is good.

Re: Reliable EV Data for Comparison

Posted: Wed May 12, 2010 6:59 am
by palmermd
AndyH wrote: We have a starting point - the standardized test cycle range of 'at least' 100 miles on the LA4 (UDDS) drive cycle. But how far can we drive at 45mph or at 65mph? We don't know yet. But we can develop an educated guess. J1634 used the same test cycle Nissan reports - the LA4 or UDDS. This data is pulled directly from the EVAmerica test results and is sorted by LA4 test cycle range.
Very nice chart. This should both ease some fears from some people and raise some in others. For me it confirms what I already knew from past EV experience. Thanks for putting this together.

Re: Reliable EV Data for Comparison

Posted: Wed May 12, 2010 7:22 am
by EVDRIVER
60 MPH is not a good freeway measure as most will drive about 65-70 at times, consumption is far greater from 60 to 65 plus, this is why the old Thinks were limited to 57 MPH even though they could go faster. At least they are more realistic on the RV4. The ford Ranger EV has a 33kwh pack FYI, I have been driving a lithium conversion lately.

Re: Reliable EV Data for Comparison

Posted: Wed May 12, 2010 8:50 am
by garygid
In all cases the constant-speed 45 mph (probably flat) range is better than the LA4 cycle, as expected. This might not be the maximum non-traffic, flat, constant-speed range, but it is representative of that type of "drivng". Clearly it is not "real world" driving, but possible.

The 60 mph constant is similarly unrepresentative of real-world driving, but the percentage drop from the very similar 45 mph test is useful. Going from 45 to 60 (15 mph increase) shows about a 30% reduction in range. One could easily suspect that increasing another 15 mph (to a constant 75 mph) would result in more than another 30% reduction in range.

Yes, very interesting numbers, thanks.

The good news is that Nissan's actual LA4-range is unknown, and could easily be higher than Nissan's 100 mile "advertised" figure. Nissan's "LA4 test" was probably just run by Nissan in their own facility.

Re: Reliable EV Data for Comparison

Posted: Wed May 12, 2010 1:33 pm
by AndyH
EVDRIVER wrote:60 MPH is not a good freeway measure as most will drive about 65-70 at times, consumption is far greater from 60 to 65 plus, this is why the old Thinks were limited to 57 MPH even though they could go faster. At least they are more realistic on the RV4. The ford Ranger EV has a 33kwh pack FYI, I have been driving a lithium conversion lately.
The point of this is to use known numbers. Yes - we all sometimes drive faster than the posted limit. We sometimes get up over 100 mph. But within the context of an overall picture this is NOT the norm.

One example is fleet maintenance. Fleets typically schedule maintenance by the hour, even for the vehicles that spend all their time on the interstate. And in spite of nearly no city driving and no commuting, the average speed for the long-haul vehicles is 30 mph.

Andy

Charging Data

Posted: Wed May 12, 2010 6:34 pm
by AndyH
Here's a look at pack size VS. charge current VS. charge time.

The first chart is sorted by total charge time. The second is sorted on charge 'miles per hour'.

I really like the miles per charge hour number!

Comparing the energy used with charger energy shows charger loss and the energy required for NiMH pack climate control.

[edit] Notice how much more efficient the MiniE's lithium charging is compared with lead and NiMH? Also note the MiniE's 208Wh/mile on LA4. I'll bet the Leaf's 240Wh/mile estimate is high. [/edit]

There are 2 lines for the Leaf. Leaf energy used is estimated '(240)'. The Leaf is well represented with the 3.3kW charger.

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Re: Reliable EV Data for Comparison

Posted: Wed May 12, 2010 6:38 pm
by evnow
AndyH wrote:J1634 used the same test cycle Nissan reports - the LA4 or UDDS. This data is pulled directly from the EVAmerica test results and is sorted by LA4 test cycle range.

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So, I'd guess, Leaf will atleast have 110 miles range @ 45mph and 85 @ 60mph.

Re: Reliable EV Data for Comparison

Posted: Wed May 12, 2010 8:36 pm
by jhm614
evnow wrote:So, I'd guess, Leaf will atleast have 110 miles range @ 45mph and 85 @ 60mph.
Is that about 70 miles at 75 mph?

I hope the sticker has City and Highway ranges. I know the Leaf will work for my daily commute (worst case, I will need some type of charging at work) but it will be nice to see some EPA verification!

j.