The Leaf vs the Honda EV+ has greater efficiency

[theaveng]

While doing a bit of research on NiMH batteries* I happened to stumble across the 1999 Honda EVplus and looked-up its official EPA rating:

46 MPG highway, 48 combined. That shows how far EVs have come in just one short decade. The Leaf has double that MPG (though the ~75 mile range is no greater).

* Anyone know where I can find a D-sized NiMH charger?
* All I've found so far are AA/AAA sized.

 

[TomT]

The test methodology used back then was so different that there is no way to directly compare the numbers.

While doing a bit of research on NiMH batteries* I happened to stumble across the 1999 Honda EVplus and looked-up its official EPA rating:
46 MPG highway, 48 combined. That shows how far EVs have come in just one short decade. The Leaf has double that MPG (though the ~75 mile range is no greater).

 

[Spies]

46 MPG highway, 48 combined. That shows how far EVs have come in just one short decade. The Leaf has double that MPG (though the ~75 mile range is no greater).

That does not sound right to me at all. Do you have a link to the data? 46 kWh per 100 miles sounds about right to me and it is the numbers EPA used back then.

I don't know what I was thinking but that does seem even close to right either. I will try to find the window sticker for the EV Plus I had but I don't think it had EPA numbers on it at the time.

 

[theaveng]

The test methodology used back then was so different that there is no way to directly compare the numbers.

I didn't realize the actual tests were changed. I thought they were still the same but with greater % subtracted off the final results.

 

[Spies]

Actual sticker from a 2002 Rav4 EV showing 27 kWh per 100 miles city and 34 kWh per 100 miles highway. Can't seem to find the sticker of a Honda Plus EV. The Rav4 EV would then have the 33.7 kWh per galon MPGe milage of about 125 MPGe city and about 99 MPGe highway. I don't believe those numbers included charging losses like the modern EPA numbers do so I would expect them to be about 15 to 20% less if they were measured today. Also from what I remember the Rav4 EV and the Honda EV Plus used pretty much the same pack and I would expect the Honda EV Plus to be more efficient than the Rav4 EV.

 

[theaveng]

Yeah those numbers are outdated.
Just like when cwerdna ___ed at me
because I claimed my 2000 Honda Insight
had 70mpg highway. He told me I was
lying because I was using outdated
numbers (and should change it to 61).

Here are the official figures direct from the U.S. Government's website:
71 kWh/mile (combined)
48 combined
49 city
46 highway
They also list the old numbers before the tests were changed:
69 city
73 highway
http://www.fueleconomy.gov/feg/Find.do?action=sbs&id=30970" onclick="window.open(this.href);return false; wiki: http://en.wikipedia.org/wiki/Honda_EV_Plus" onclick="window.open(this.href);return false;

 

[Spies]

I have to provide a link to fueleconomy.gov? Um..... okay. Kinda like asking for a link to wikipedia.

Those figures just seemed so whack that I did not even stop to think they came from fueleconomy.gov. Anyway its always nice to post references when quoting figures. The figures from fueleconomy.gov still seem totally off.

 

[theaveng]

I suspect the main difference is Li-Ion is greater efficiency than NiMH, so that's why the MPGe numbers have doubled. Can I buy a used EVplus? Or any other old EV car? (An official production car, not a conversion.)

 

[Spies]

There is no way that a Honda EV Plus was that inefficient. For example here are the updated numbers for a 2002 Rav4 EV and the 1999 Honda EV Plus http://www.fueleconomy.gov/" onclick="window.open(this.href);return false;

2002 Rav4 EV
78 MPGe Combined
87 MPGe City
69 MPGe Highway
43 kW-hrs/100 mi

1999 Honda EV Plus
48 MPGe Combined
49 MPGe City
46 MPGe Highway
71 kW-hrs/100 mi

Something is seriously not right here.

 

[theaveng]

It's a government conspiracy! (Alex Jones, is that you?) LOL.

But seriously: The Rav4 EV was ranked by greenercars.org as one of the top 10 greenest vehicles, but I never saw the EV+ there. Maybe it wasn't that good. Not all small cars get high MPG

 

[johnqh]

1 kWh is 1 kWh, it doesn't matter what kind of battery it comes from.

Electric motor is a mature technology. I doubt its efficiency has improved much over the last decade or two.

So it comes down to drag coefficient x frontal area (wind drag) and weight (rolling resistance).

New battery technology would give it more kWh density, but it has little impact on the MPGe.

Regeneration has more impact on local MPGe. However, for highway, it is pretty much about drag coefficient.

 

[Spies]

But seriously: The Rav4 EV was ranked by greenercars.org as one of the top 10 greenest vehicles, but I never saw the EV+ there. Maybe it wasn't that good. Not all small cars get high MPG

I had a Honda EV Plus for almost 6 years until they were all taken back by Honda and destroyed. I understand a few where used briefly as hydrogen fuel cell test cars before they met their demise. It may be possible that the Rav4 EV made the greenercars.org list because it was available for purchase for a brief time while the Honda EV Plus was not. What happened to the Honda EV Plus is pretty close to the same thing that happened to the GM EV1.

I should add that I felt the Honda EV Plus was an excellent EV and still wish I had it.

 

[theaveng]

Greenercars also listed the lease-only EV1 as one of the top 10 greenest cars. But no EVplus... I guess it just wasn't good enough. Not all small cars get high MPG

1 kWh is 1 kWh, it doesn't matter what kind of battery it comes from.

Don't NiMHs have higher internal resistance than Li-Ions? Thus some of the energy would be wasted as heat.

 

[johnqh]

Greenercars also listed the lease-only EV1 as one of the top 10 greenest cars. But no EVplus... I guess it just wasn't good enough.

1 kWh is 1 kWh, it doesn't matter what kind of battery it comes from.

Don't NiMHs have higher internal resistance than Li-Ions? Thus some of the energy would be wasted as heat.

Yes. However, aren't batteries measured by output? So 24kWh is the output energy (after the resistance is already deducted). I may be wrong though.

 

[Spies]

I guess it just wasn't good enough.

Whatever

 

[theaveng]

Well it's a Honda. Folks that drive Priuses tell me, "Honda's hybrid design is a failure!" Mayhaps the same is true of their EVs. (just kidding). Clearly something was wrong with the design if Toyota got 69MPGe highway and Honda only got 46. GM's EV1 was only rated 39MPGe highway with the lead-acid version* so I guess it truly is possible to make a crap EV.

* 94 MPGe with the upgraded NiMH model

 

[Spies]

Clearly something was wrong with the design if Toyota got 69MPGe highway and Honda only got 46.

Or there is something clearly wrong with the numbers entered at http://www.fueleconomy.gov" onclick="window.open(this.href);return false;. Is that so hard to believe?

From what I understand the Honda EV Plus and the Rav4 EV used the same 24 12-volt 95Ah NiMH batteries capable of storing 27.4 kWh of energy. I could easily get 80 miles on a charge freeway driving and up to 120 miles city in the Honda and is close to the 81 mile EPA range mentioned in the Wikipedia article. Now if the Honda was really as inefficient as 71 kW-hrs/100 mi it would need a battery capable of storing 57.51 kWh to travel 81 miles!
So at worst the Honda EV Plus and the Rav4 EV numbers should be similar.

 

[KeiJidosha]

Well it's a Honda. Folks that drive Priuses tell me, "Honda's hybrid design is a failure!" Mayhaps the same is true of their EVs. (just kidding). Clearly something was wrong with the design if Toyota got 69MPGe highway and Honda only got 46. GM's EV1 was only rated 39MPGe highway with the lead-acid version* so I guess it truly is possible to make a crap EV.

* 94 MPGe with the upgraded NiMH model

All water under the bridge. Even Honda admits it's early EV products needed improving. "Why don't you just dig a hole, and bury it!" Nissan's Altra is from the EV+ generation, so a more apt comparison. LEAF should compare to the Fit EV.

 

[Spies]

GM's EV1 was only rated 39MPGe highway with the lead-acid version* so I guess it truly is possible to make a crap EV.

When I go to http://www.fueleconomy.gov" onclick="window.open(this.href);return false; and choose a 1999 GM EV1 with NiMH I get the following:
37 MPGe Combined
35 MPGe City
39 MPGe Highway
91 kW-hrs/100 mi
Total Range 105
Fuel to Drive 25 Miles 22.75 kW-hrs

I had no idea the EV1 came with a 95.55 kWh battery! Conspiracy theory or not the efficiency numbers for a number of electric vehicles in the fuel economy database are simply wrong. I suspect there was either an error in importing the data or an error in the formula computing MPGe. The total EPA range numbers do seem about right for the electric vehicles I have looked up so far so whatever the issue is does not seem to impact all the data.

Perhaps I will contact NREL and see if they will look into the error and see if it can be fixed for historical reasons.

 

[cwerdna]

Yeah those numbers are outdated.
Just like when cwerdna ___ed at me
because I claimed my 2000 Honda Insight
had 70mpg highway. He told me I was
lying because I was using outdated
numbers (and should change it to 61).

I don't believe I accused you of lying. You were and are again using misleading figures, from what's currently in your sig. As a refresher for those who didn't see the earlier conversation on this topic, see http://www.mynissanleaf.com/viewtopic.php?p=226112#p226112" onclick="window.open(this.href);return false;. Per http://www.fueleconomy.gov/feg/Find.do?action=sbs&id=15606" onclick="window.open(this.href);return false;, the adjusted EPA values using a methodology that has been in use since 2008+ model year vehicles are now 49 city/61 highway, 53 combined for a 2000 Insight.

It's just as misleading to claim today (more than 5.5 years after the old test methodology could no longer used by automakers for the purposes of Monroney sticker values) that your car is "70 mpg" as mine is "60 mpg". I don't go around telling people I have a 60 mpg Prius, nor should anyone else who drives an 04-07 Prius.