I agree that a SOC % gauge would be nice. I use a ScanGauge in my plugin Prius and that is one I always have on. I think Nissan went with the 12 dot graphical display because it more closely resembles a gas gauge that most people are used to. Also 12 evenly divides by 4 to represent Full, 3/4, 1/2, and 1/4 again like a gas gauge (notice the division on the gauge between dots 3 and 4).

“Within 15 miles, I had seen ranges of 102, 84, 66, 82 and 78.” If it instead had reported 102%, 84%, 66%, 82%, and 78% would that be an improvement?

Personally I like the miles to depletion indicator. I drive miles, I don't drive percentages. Mapping the miles to depletion onto the Nav map screen is also a very useful feature for the typical driver.

As I wrote above, I think this discussion is silly, but I wondered what additional data I might enjoy as a future EV owner and thought of this:

A Prius will show the MPG of 5 minute segments as a bar graph. How about the LEAF displaying kwh/mile in user chosen time intervals ? Drivers would quickly learn consumption rates for different driving conditions.

Indyflick - the important part that you are missing is that while the "miles remaining" indicator can and does vary wildly, the SOC meter does not. You go up a steep hill and the car begins to assume that your next hour of driving will be up the hill. The SOC guage only reports that amount of battery that was *actually* used. It is a significant difference. If the car could accurately report the miles remaining, I'd agree that it would be a GREAT bit of information. But nobody has figured that part out yet. Until they do, I'd like to know exactly how much is in my "tank." Having an accurate SOC gauge is one of those things that you can do without - but once you've had it, you can't imagine being without it.

@patrick - the SOC gauge would report the usable range of the battery charge - just like the usable gas in your tank. Knowing exactly how much is in the battery "tank" allows you to make smarter decisions on how to best use the stored energy while protecting the battery from too many deep cycles.

@Familyguy - I agree that the main reason this is important is because of the "limited" range of EVs. And the desire to protect the expensive battery. While I don't think the desire for accurate information will ever "go away" with better batteries, it will likely become less important. The fact of the matter is - it is important now, and it is missing on the current crop of EVs coming to market. Too often, the EVs are trying to emulate gas cars when we have far better, more relevant options. Options that EV drivers *know* are important, but the car makers forgot to ask about.

Let's see if I can summarize correctly:

1. We have experienced EV drivers who want an accurate SOC number in their EVs. (you can put a tick mark by name as well).
2. We have non-EV-experienced drivers who are OK without it because they've never had it or needed it in their gas cars.
3. We have the concern about how difficult it is to correctly report the SOC - though it has been implemented amazingly well in EVs from 15 years ago... so we know it is possible!
4. We have those who point out that 12 is more easy to divide into fractions, noting that ten segments only works well for a 100 mile range car.
5. We have me wanting to point out that what I want - and what Marc really wants - is a percentage gauge. 0-100% of the charge. Marc and I both have this to a 10th of a percentage in our current cars. And as I said before - once you have it, you can't be without it. I don't want any sort of pretend analog gauge. I want a number. A percentage of what I have left. Or... as another option, how many kWh's remain in the "tank."
6. And then we've got people consuming bandwidth to tell us that we're wasting bandwidth.

I think the bigger point here (almost hidden in Marc's message above) is that there is so much untapped knowedge out there - and the EV makers would do well to ask experienced EV drivers for input - instead of learning all this same stuff again and again. In general, car makers seem to think that the general driving public would like their EVs to be as much like a gas car as possible. And implementing some of those "features" tends toss away some of the very things that make EVs superior to gas cars. One hopes that they won't add vibration and gear changes next! We're already adding back the noise pollution. :(

While some of you clearly believe that this argument is unnecessary, some really think it's a problem. I think what Nissan could have easily done is give the driver the choice of what reading they want displayed. If a driver like Marc wants to see SOC, then let him choose that. If a driver like Sagebrush wants to have the car calculate range for them, so be it. Point is, in this day and age the instrument cluster is essentially a big LCD and should be configurable in any way the driver likes—the best example of this is the Ford SmartGauge on the Fusion Hybrid. I know Nissan has the SOC numbers available in the car's computer because SOC is displayed on the LEAF iPhone app (albeit at a very low granularity), so it wouldn't be anything but a few lines of code to make it display on the instrument cluster.

SageBrush,

Sorry to put words in your mouth... I was mostly using you to illustrate a point and not really meaning to imply you felt one way or another. I could easily have used examples of "Bob" and "Ted" instead of you and Marc.

You would think that Nissan has programmed its displays with the future in mind, but when Marc and I were in Japan back in June as two of the first five Americans on the planet to test drive the LEAF, it was amazing how little they had actually thought about the SOC question and about future-proofing their display. What it came down to is that these display changes couldn't be implemented in the current generation LEAF, but that they would seriously consider it for the 2nd generation LEAF when it starts being produced in the U.S.

Thank you @darelldd for saying much I would have said (had I not been serving on a jury.) And, as usual, more amusingly.

I think I did not explain to Brad sufficiently that perhaps the essential difference of the two metrics - SOC v Range - is the driver's connectedness to the information. Let me try to explain.

SOC is, in a sense, constant, as close to linear as achievable by the engineers. (I know it's doable because Toyota did it over a decade ago and I continue to drive a RAV4 EV and see the SOC displayed daily.) SOC merely tells you what remains in the battery. (Needless to say I always presume 100% is not really the absolute top and O% is not the true bottom.) SOC will decrease at the rate of depletion and increase with replenishment through regeneration. SOC presented to the tenth (i.e. 87.4%) allows the driver to use a real-time metric where the only variable is his/her driving. The reward for regeneration is reflected in the increase in the SOC, which I find meaningful and awesome. The penalty for a lead foot is more rapid decline than 1% per mile.

On the other hand I experienced the Range Meter's occasional increase to be unrelated to anything I was doing at that moment. Other, undisclosed variables were influencing it, and at intervals unconnected to my real-time driving experience. I find the SOC meter leaves me feeling in control, whereas the Nissan algorithm puts the car in control. That said, I see no reason both options shouldn't be available. Together, they might be even more useful, if graphically difficult for a carmaker to consider displaying together.

The reason this seems so important to me is that I believe the SOC meter has a greater chance of promoting efficient driving, and thus is in the interest of Nissan and the promotion of electric cars generally. I want to wake up to the number 100%. When I awoke to a range of 93, I found it dispiriting. 100 miles is conveniently the aspirational range, at least for Nissan. 1% per mile. Easy. It is in Nissan's interest that drivers' share that aspiration. It doesn't help achieve our goal if the car has already decided "no, you can't."

> @darelldd, so what happens to that SOC when you go back down that hill? My point is that the SOC is also not a constant, if the EV has regen.<

What happens when you go back down the hill, is that you are shown exactly what you have to work with. It is a real number, where the other is nothing more than a guess. The range-o-meter (as we used to call it in the EV1) swings wildly, the SOC meter does not. You go up a hill and you lose charge. You come down and you might gain some back, or simply use less. Regardless, you know just how much you have at any moment. Having the car tell me that I can suddenly go way more miles just because I spent five minutes going down hill isn't useful to me.

>Perhaps the answer is to allow the driver to select % or miles or even provide both.<
Indeed. There's no reason that the car can't provide whatever the driver wants. I've spent some time working with "user interfaces" and ones that are dumbed down for the lowest-common denominator for the reason if "we don't want anybody to be confused" really tick me off! There's no excuse to not let savvy users see what's available. You simply default the car to idiot mode, and hide the unlock sequence in the owners' manual - that secret place that nobody ever looks unless they really DO want to get everything out of the car. The unlock allows configurability of the display, and always contains a reset to put everything back to idiot mode in case the car is sold or whatever.
.

First, welcome to "Darell Hour" at PIC. ;)

@Sagebrush -

>The suggestion of experienced EV drivers that they be sought out and heard is interesting. The merit is clear, although I suggest that they temper their anticipated utility by realizing that very early adopters have different needs and wants than later very-early-mainstream owners<

Yeah, I see how this appears. Looks like a bunch of EV drivers all full of themselves. "Listen to me! I know exactly how things should be!" And of course there's no one right way to do everything. The thing is, EVs are different than gasoline cars. Most consumers have been driving gasoline cars and may initially think that it would be best to make EVs simulate the gas experience as closely as possible - but it has been shown countless times that direct EV experience quickly demonstrates that there are better ways of doing things. (Ever driven a gas car a long distance without ever using friction brakes? I mean without ever using that left pedal?) The Prius is a good demonstration of this idea: To design a new/better Prius would it be best to talk to current Prius drivers about how things should be improved... or best to talk to Joe Sixpack about maybe dialing it back a bit and making it more mainstream with a traditional shifter, 500 hp and lower gas mileage? ;)

So consumers only think in terms of gasoline cars and infrastructure. The car makers only really think in terms of gasoline cars and infrastructure. If we wanted better gas cars, then we need to ask the people who have the most experience with them, right? But if we want to make the best electric car... who would know the best? At least to get the ball rolling? To get those first units out there, doesn't it seem wise to get a head-start and equip them the way that EV drivers would like to have them equipped, instead of fully emulating the gas car experience?

The thing is... maybe EV drivers don't have all the answers. Maybe as you say, the utility of our comments really does need to be tempered. But... BUT, the car companies could take or leave as much of the information as they wanted. But they can't benefit from any of it if they don't ask. And that's the big part that's been missing. If I were going to build something that others have many, many years of direct experience with... I'm going to talk to those people if I expect my product to be the best it can be. I might not use everything I hear, but I'm sure as heck going to listen.

Do you think GM could have learned a thing or two from the EV1 drivers? Maybe Toyota would want to talk to current Rav4EV drivers while they gear up to build a new version? Nissan could tap any of this... yet for the most part, it just isn't happening.

OK, I'm seriously starting to ramble, but I'm trying to wait out the rain before I have to take my dog out for a walk. ;)

Darell, I do not doubt for a moment that tapping EV driver experience is useful, and I'm sorry to hear that the auto companies are not asking for input. My point was more to encourage you and the rest of the greybeards to not simply ask for an interface you want, but to consider an interface that would serve well a larger net of people.

I agree that part of the solution is to make the interface customizable. E.g., the number surrounded by the hash marks can cycle between 'range left', SOC %, and kwh available.

Grant,
The flip argument is that once you transition to a new consumption rate, you do not want the prior rate to be considered. For example, lets say you are driving 80 mph on the freeway at 330 wh/mile, and then enter city driving at 220 wh/mile. If your question is how far you can drive in the city, you do not want your earlier freeway driving to be considered.

This is why I think that knowing residual battery capacity and ~ current consumption rate is the most useful (to me). The problem is that it requires a bit of mental calculation that does not come easy to many people. Perhaps a useful alternative is to cycle through range numbers based on immediate, last minute, and last 5 minutes of driving.

Darrell, I meant that within a hashmark there is ambiguity, and assuming the range meter fluctuates by 50%, that last mile might be 0.5 miles, or 1.5 miles.

Just out of curiosity, do you keep a mental picture of miles/%, or miles/kwh (or their inverses?)
Personally I am pretty wed to energy available and energy consumption rates, and I am pretty sure I would tend to translate other data into that framework. Heck, I do as much with my Prius and starting from mpg is more of an annoyance that anything Nissan could think to display.

@SageBrush - I generally picture miles/% for general "how far can I go?" considerations. When I want to play the efficiency game, I ceratinly want Wh/mile - something that I can flip my (aftermarket) display to easily on the fly. For anybody interested, here is the Geek's dream that most Rav4EV drivers use. And yes, I DO realize that this isn't something that your average drive would want. I only offer it to show what is available:
http://evnut.com/images/rav4/rav4info_gps/rav_palm_front.jpg

That shows one of two configurable pages. As set up, the big number at the top is %Soc remaining, then in order:
Pack Voltage and instantaneous current draw (negative means out of the pack)
Power out of the pack (a calc on the current out of the pack)
Cumulative energy in and out of the pack (so regen - motive energy)
Total Energy since reset (the result of above calc)
Battery Temps: Ambient and three rows of batteries
Battery Voltages: Average, Max and Min (of individual modules)

Bar on the side graphically shows instantaneous current in and out.

Some may want to discount the views of members of the EV community, but everyone that buys a Leaf becomes a member of the EV community instantly.

I drove gas cars for 30 years before I drove an EV. I've been driving two different EVs for over two years now and I've learned a lot. It's changed how I drive and I enjoy driving now more than ever. I'm online in multiple EV communities and believe my thoughts expressed here are representative of what I've heard from most other drivers.

Yeah, what Tom Saxton says and the other EV users. Although I'm not an EV user yet, I do try to drive my Prius as a hypermiler and use all the relevant info I can get.

Even in a gas powered car I have always swore under my breath about inaccurate, non-linear, low granularity gas guages. I have hoped that EV cars would have a more accurate with proper granularity for the amount of charge remaining. Seems like a no-brainer to me and I have been driving gas-only cars for nearly 40 years (including a hybrid now for over 7 years).

I also have hoped that with the advent of GPS that a better range remaining indicator could be made for both gas & EVs. Assuming a driver inputs a destination into the navigation system, the car now knows the route. There is now enough information available in data bases that the car would know at least what the posted speed limits are all along the route and the elevation changes. Add in a few other things that should be possible to obtain from modern instruments & communications such as outdoor temperature, is it raining, wind speed & direction and traffic, and I bet the range indicator could be a heck of a lot more accurate.

EVDriver,
Superior to a kwh gauge ?

@Curt -

EVs became wildly popular when gas was $4 a couple of summers ago, so $5 would be the nail in the coffin for gasoline one would hope. The graph of the number of new hits on my EVnut site followed the price curve of gasoline almost exactly. I no longer have that data - I really should have printed it out for display!

As for living with less honest gauges, I totally understand the motorcycle angle (having ridden one for many years for commuting and fun). Of course the motorcycle always had a reserve to switch on AND it could take on gasoline somewhat conveniently (if you don't count the gas drips on the tank!). An EV is another animal... and even though some folks may not *need* a more accurate gauge (like those who simply never use the full range of the vehicle) there's really no reason to NOT include an SOC (or kWh - I'm listening, Sage!) gauge for those of us who would make use of it.

@EVnow -

Ok, so I'll take that as a "no" to my question that wasn't answered. I sure didn't mean for you to read between the lines of my EV ownership question and assume that I was discounting what you had to say - it was just for another data point. I don't believe for a minute that "only the current EV drivers know what is best for 'the rest of us'. I don't think I said it and I sure didn't mean to imply it. What I do believe is that current EV drivers know what has worked best to get the most out of an EV. And current EV drivers also have extensive gasoline-car experience (even concurrently) so we aren't a bunch of goobers (well...OK) living in a bubble. Oddly enough, in this case what's best from an EV driver's perspective doesn't conflict even a tiny bit with what you see as the best situation. All the information can exist side-by-side. So... uh... what's the issue exactly? You are free to discount the experience of EV drivers if it does not fit your view of things. I just don't see any advantage in doing so.

What I hear you saying is that long-time EV drivers are arrogant if they think they know what would be best to have in an EV. While at the same time you know for sure that we're all wrong. Sorry, all *wildly* wrong - ("but ev-drivers are widely off the mark here")

Do you see the problem I've having with those two conflicting ideas? I'm wrong (and arrogant) because I have EV experience. You are right (and not arrogant?) because you have no EV experience.. and somehow have a better grasp of what "the rest of us" want? I drive an EV... but I am still part of "the rest of us" as much as you are.

Yes, I do take offence at being labeled arrogant, and being out of touch just because I have EV experience and have made suggestions to improve them. Does the medical profession take brain surgery advice from dermatologists because there are more people with skin problems than with brain problems? OK, I'm rambling.

If you're saying that all cars need to be dumbed down to the lowest common denominator, then that's a discussion that goes well beyond just talking about EVs.

I'm with Tom on this one. The level of reaction against supplying the option to have more information available is truly surprising to me—especially since all it would take is making information the car already calculates available for the driver to see if he or she wants.