a checklist for the perfect electric vehicle

[ChrisC]

All -

This is a document that I've been working on for a long time. I just completed the first version of it, and still need to go through and refine it a bit, but I wanted to go ahead and put it out there (in this lower profile location) to let you guys take a look and comment on it.

a checklist for the perfect electric vehicle
http://electrifyatlanta.com/wp/?page_id=25

In particular you all might be interested in the EV subtleties section, a list I've put together over the past 5 years of observing the EV market, owning and driving a Chevy Volt, and test driving nearly every EV out there. You will likely disagree with some of my positions in the document, but I really do not mean to open up debate on it. Really, who needs yet another argument about creep mode? But I did want to make a very complete CHECKLIST of everything to look at when evaluating an EV.

I will soon need to make a decision about what my next car will be, and this list is what I will use to structure that process. I don't expect any car on the market to give me everything, although it's possible and that's why this list is also billed as an open letter to automakers. As it stands, I will need to trade off pros and cons and decide which features I can live without.

Let me know what you think, and thanks!

- Chris

 

[surfingslovak]

Nice list Chris! I note that a heat pump is something you seem to appreciate, and I couldn't agree more. How about highlighting heated seats and steering wheel a bit more? Both trigger strong favorable response from those that have them in their EV. Same goes for the sunroof. My personal pet peeve is freeway driving efficiency, which is directly related to aerodynamics and aesthetically pleasing exterior. I think there some room for improvement and good efficiency at higher speeds would translated to longer freeway range. This might be more typical of US conditions, but it's important nevertheless. How do you feel about all-LED lighting? Also, the charge port should be in the front of the vehicle (the Infinity LE had a particularly interesting design approach).

 

[kullenberg]

I enjoyed your treatise on EV's. Seems well researched and written. I'm on the edge of getting an EV. I presently have a 2012 BMW 128i, that has only 7000 miles in 2 years. I really can't justify replacing it this soon, besides, I rather like it. Were I to take the leap to an EV, it would either be a Volt ( or Cad ELR) or the BMW i3. It remains to be seen what the i3 pricing will be, when they add in options. My experience with BMW is they tend to really drive the price up with options. I got a very good deal by buying through USAA. (I'm retired military). Anyway, nice piece of work, I enjoyed it.

 

[ChrisC]

Thanks guys!

Great feedback surfingslovak, you point out a few things I'd forgotten about. I do indeed loooove the heated seats in the Volt and feel like I can no longer live without them!

Personally, I think charge port on the front is a bad idea. First, it makes it hard to reach if you happen to have to back into a charging spot. Second, if you get in a minor front impact fender bender, you may find that you can't charge your car (e.g. flap won't open or similar). I once had to go three days without being able to charge my Volt and let me tell you, that sucked :/

I actually don't care much about efficiency, since I feel like these cars are already wildly more efficient than other cars. I go more for styling (i.e. at the expense of aerodynamics) and high power electric drivetrain (at the expense of low power efficiency). Of course I have a short commute (and a REx in my Volt) so I can floor the accelerator whenever I feel like it and never have to worry about the impact to range.

Driving an EV is how I assuage my guilt over having a lead foot

I'll revise the document later this week. Thanks again for the feedback.

 

[Northwestern]

Chris: Thanks for the document! However, while your charging rates may be attractive, here in Southern California most of us will be hitting 30 cents/kwh tiers, making the i3 anything but efficient (costs more than a Prius). Now I only drive about 6,000 mi./year, and I can operate within the 19 c/kwh tier most of the time. In any event, I noticed your comments on the "low current mode level 1 charging." Is it more efficient to charge at 6 amps than 12 amps, where efficiency is measured by electrical delivery to battery vs. electrical charges per utility? I saw a heat-loss equation somewhere where heat loss is a function of the square of the ratio (amps delivered/rated amps of wire), so if this is the case, better efficiency keeps me off the dreaded 30 c/kwh tier.

 

[ChrisC]

I've just updated the document, including removing a TON of typos

Northwestern: you are right that we have great electric rates here in Georgia, and in fact that's a key reason that metro Atlanta is one of the top EV markets in the country. The average customer pays 11 cents/kWh here. I signed up for the Time Of Use (TOU) rate plan, which halves my overnight rate in exchange for doubling it on summer weekday afternoons. So my overnight power costs 5-7 cents/kWh! Sorry

While you do have some heat losses in wire, those small losses are likely dwarfed by the OVERHEAD of the charging system. No matter the charging rate, you are losing some watts in the EVSE and in the charger (rectifier) block in the car. So for ultimate efficiency it's better to charge FASTER, but you're still only talking about maybe a 5-10% difference.

I get annoyed whenever the performance of Prius is mentioned in the context of EVs. The Prius is simply not comparable to a Chevy Volt or BMW i3, as the Prius is a much weaker car. You might as well compare a Chevy Cruze to a Ford Mustang. Now, compare to a Nissan Leaf? Sure.

 

[evnow]

In software engineering we say - tell us your requirements, not the solution.

You are mostly giving solutions - instead of real requirements.

For eg : Instead of saying xyz HP motor - your requirement should be I want 0-60 in x seconds or some other performance spec
or
It should have a TMC - should be battery should last x years without degrading more than 20% even in hot conditions etc
...

 

[ChrisC]

Fair enough, you're right, I tried to do that.

But it's a lot harder for people to dig up the battery degradation spec, rather than just see if the battery has a TMS. The carmakers drag their feet on the, and use weasel words in the non-spec marketing material. Maybe someday battery technology will evolve to achieve the desired longevity and temperature insensitivity without a TMS, but for now it's a requirement.

 

[evnow]

You are going to get chemistries that won't require TMS. Some already don't (like the titanium ones).

Back to the list - the biggest one should be the minimum EV range.

For PHEVs : Should cover commute in winter and 70% battery capacity.

For EVs : Should cover normal city driving in winter, at freeway speeds and 70% battery capacity.

 

[ChrisC]

The horsepower section has been rewritten, and I added a bit about range.

Thanks for the feedback!

 

[Yiiikes]

Chris,
Not much info for the i3 in your list, are you waiting to drive one to publish your ratings?

 

[ChrisC]

I did in fact do a pair of test drives in early December, and updated the checklist with the i3 references before writing my piece for Tom's blog on December 17th.

http://bmwi3.blogspot.com/2013/12/the-first-volt-owner-in-georgia.html