in fact, now that i think about it, this is probably why the existing SoC meter has such coarse granularity. they must have chosen this as a natural mechanism to damp out the SoC variations from their estimate. in fact the one Japanese engineer who did ask a question of the group asked something along the lines of "but what do you think about the SoC variation?" and in the context of what Kadota-san said later, he must have been asking "do you really want to see an SoC gauge that bounces all over the place?"astrorob wrote: it seems that even their estimate can cause "mysterious" jumps in the SoC and they want to shield the user from that confusion.
I think the most important DTE is the one presented at the start of the trip i.e. when Leaf knows the SOC more accurately. The efforts to get better DTE should be focused on that. That DTE can then be adjusted to take care of actual conditions compared to what was used at the beginning (for eg. estimate was based on 40 mph, but it was actually 50 mph).astrorob wrote:overall i think he was trying to convey the idea that there's no "true" SoC and any direct report of the SoC to the user will be just as much an estimate as the DTE currently is. of course reporting the SoC would remove the extra component of the recent driving history from the computation and perhaps be a little more clear to the driver.
yes, i would agree with that.evnow wrote:I think the most important DTE is the one presented at the start of the trip i.e. when Leaf knows the SOC more accurately. The efforts to get better DTE should be focused on that. That DTE can then be adjusted to take care of actual conditions compared to what was used at the beginning (for eg. estimate was based on 40 mph, but it was actually 50 mph).astrorob wrote:overall i think he was trying to convey the idea that there's no "true" SoC and any direct report of the SoC to the user will be just as much an estimate as the DTE currently is. of course reporting the SoC would remove the extra component of the recent driving history from the computation and perhaps be a little more clear to the driver.
Perfection shouldn't become the enemy of good. We need Nissan (and other OEMs) to continuously improve DTE algorithms. It is a critical part of getting more acceptance for EVs until battery technology improve enough to make range not a big issue.
Yes, exactly! That's kind of what we said up front in our SOC presentation and why we suggested that they make it user-selectable. Keep it simple (default) for those that want it uncomplicated, but provide the option for those that know how to use it. We also asked them to provide the OBD II codes so that aftermarket SOC meters could be made while they work on their strategy.astrorob wrote:perhaps rather than trying to nail an exact number they could give a best-case and worst-case estimate. i think they are always battling between confusing the ordinary user with a load of information and simplifying the information too much. they seem to be painfully aware that they have to present the information in such a way that it can be understood by the average person, and not an engineer EV enthusiast. my personal opinion is that they are going to try very hard to come in on the conservative side of any estimate. the worst thing that could happen is that they tell you 20 miles are left and there's only 5 in real life. their lawyers probably worry about what could come of consistently overestimating the range...
So you're sayin'..... there's going to be a Nissan sports EV. I'll take that as a definite, then.TonyWilliams wrote: 4 new EVs coming (or three more, actually, I think). Utility, sporty, something else.
The Nissan team was here in the USA for official acceptance of a new EV at their proving grounds in Arizona.
KeiJidosha, doing his usual quiet, unsung helpful job. Did you drive the MiniE up there?KeiJidosha wrote:BTW, Your personal Chargepoint card will not operate on Google campus. Hopefully our hosts have a card with access.
One final footnote on the charging. I will make a sweep through all the L2 charger areas about 10 min before the meeting to make sure that all the chargers are activated. Howard, would you mind sending a last minute reminder to folks that have asked for charging to make sure they leave their charge port door open even if they can't activate the charger? I'll make sure they get plugged in. I don't want to have anyone stressing out because they can't get the charger to work.
I have repeatedly seen the SOC *decrease* during regenerative braking, immediately following a long mountain ascent. Driving up CA-330 on my way home, I climb almost 5000 feet in about 14 miles (see http://www.mynissanleaf.com/viewtopic.p ... 60#p143277" onclick="window.open(this.href);return false;), then descend about 150 feet in elevation. Almost invariably, I have seen my SOC drop during regen braking on that small descent. Sometimes this even translates into losing a charge bar. After transitioning from continuously discharging the battery to charging, perhaps the car is able to refine/improve its estimate of OCV.gascant wrote:As much as I believe Kadota-san's explanation of the difficulty in determining true or estimated SOC, I will also say that in 4 months of owning the SOC meter, I have never seen it jump suddenly (more than the 0.3 or 0.4 % that it changes during normal vehicle operation). So, they might be applying some sort of smoothing function to the measurements. And if it did jump around, you might also expect it to jump up occasionally. I have only seen the SOC increase when I've been in regen mode going downhill.