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Why not just display estimated number of kWh left?

Posted: Tue Nov 27, 2012 8:25 pm
by jlsoaz
Maybe this has been answered, but at a quick search I do not see it. I don't dislike the 12 bars display, nor the estimated miles of range left, but why not add a way to view estimated useable kWh remaining?

(Come to think of it, I don't know that I've owned an ICV that just gave gallons, but my cars have generally been pretty basic. In any event, maybe it would be useful to see the estimated kWh.)

Re: Why not just display estimated number of kWh left?

Posted: Wed Nov 28, 2012 3:05 am
by garsh
Yes, that would be nice.

It sounds like the 2013 will show percentage battery remaining, which is an improvement over the GOM. But I'd rather see kWh too.

Re: Why not just display estimated number of kWh left?

Posted: Wed Nov 28, 2012 8:25 am
by garygid
Apparently Nissan did not want to reveal the "naked" truth,
and decided to hide the actual capacity-loss issue as much
as possible.

Also, a really reliable fuel-quantity value appears to be
rather difficult to estimate, and possibly misleading at times.

Thus, we have the GID-Meter, to give us a better (not perfect)
display of a practical, usable fuel-quantity value that the LEAF
"hides" inside itself. But, it can, occasionally, be misleading.

However, most GID-Meter users find it very helpful, and
some say that they hate to drive without their GID-Meter.

See the LEAF CANbus subforum, or my
http://www.wwwsite.com/puzzles/socmeter/" onclick="window.open(this.href);return false;
site for more info.

Re: Why not just display estimated number of kWh left?

Posted: Wed Nov 28, 2012 8:50 am
by TickTock
True. My wife usually takes every opportunity to drive the Leaf but when I had the gid-o-meter out for a sw update she refused to drive it until it was back in place. The Leaf's built-in GOM stresses her out. I agree kW makes the most sense - especially since they provide the driving efficiency in mpkWh but it's clear Nissan didn't want to disclose the actual usable capacity.
garygid wrote:Apparently Nissan did not want to reveal the "naked" truth,
and decided to hide the actual capacity-loss issue as much
as possible.

Also, a really reliable fuel-quantity value appears to be
rather difficult to estimate, and possibly misleading at times.

Thus, we have the GID-Meter, to give us a better (not perfect)
display of a practical, usable fuel-quantity value that the LEAF
"hides" inside itself. But, it can, occasionally, be misleading.

However, most GID-Meter users find it very helpful, and
some say that they hate to drive without their GID-Meter.

See the LEAF CANbus subforum, or my
http://www.wwwsite.com/puzzles/socmeter/" onclick="window.open(this.href);return false;
site for more info.

Re: Why not just display estimated number of kWh left?

Posted: Wed Nov 28, 2012 11:24 am
by Herm
The Chevy Spark EV will provide THREE continuously updated remaining range estimates.. I bet they do a good job.

Re: Why not just display estimated number of kWh left?

Posted: Wed Nov 28, 2012 11:43 am
by ebill3
Percent of charge remaining will be nice, but I doubt that remaining kWhs would me meaningful to most folks. For techies? OK.

Bill

Re: Why not just display estimated number of kWh left?

Posted: Wed Nov 28, 2012 1:54 pm
by jlsoaz
garygid wrote:Apparently Nissan did not want to reveal the "naked" truth,
and decided to hide the actual capacity-loss issue as much
as possible.

Also, a really reliable fuel-quantity value appears to be
rather difficult to estimate, and possibly misleading at times.

Thus, we have the GID-Meter, to give us a better (not perfect)
display of a practical, usable fuel-quantity value that the LEAF
"hides" inside itself. But, it can, occasionally, be misleading.

However, most GID-Meter users find it very helpful, and
some say that they hate to drive without their GID-Meter.

See the LEAF CANbus subforum, or my
http://www.wwwsite.com/puzzles/socmeter/" onclick="window.open(this.href);return false;
site for more info.
Hi Gary,

thanks much for the response and for creating the GID meter. The link you provide does not say (or maybe I am jusat missing it) if the GID meter displays estimated kWh information. I've read something somewhere about GIDs as a unit of energy, and then I think somewhere there was an equivalency equation to kWh, but do users find they sometimes like to see kWh?

I have considered ordering a meter, but am very non-technical, and moving slowly on my own learning curve, so held off on the decision.

It may be that Nissan's decision not to display estimate kWh is related to concerns about providing transparent (or misleading) information that could be negative for them as regards battery degradation discussions, but I don't know.

Re: Why not just display estimated number of kWh left?

Posted: Thu Nov 29, 2012 10:03 am
by TonyWilliams
jlsoaz wrote:... does not say (or maybe I am just missing it) if the GID meter displays estimated kWh information. I've read something somewhere about GIDs as a unit of energy, and then I think somewhere there was an equivalency equation to kWh, but do users find they sometimes like to see kWh?
The LEAF battery is 24kWh, and for whatever reason, Nissan decided to divide that by 0.080kWh to arrive at 300 "Gids" for a 24kWh battery.

The actual stored energy is limited to 22.48kWh, or 281 Gids. When we finally retrieve the energy, there is about 21.3kWh available in a new 70F or warmer battery. That makes the each "Gid" worth 0.0758kWh (21.3 / 281 = 0.0758).

Of that 21.3kWh "available", there is about 2% at the bottom of the battery pack (.02 * 24 = 0.48kWh) that is not usable (just as there is some at the top not used between 22.48 and 24). Therefore, the final tally of usable energy for that new battery is 21.3 - 0.48 = 20.8kWh to propel the car and run all the systems.

We just use 21kWh for easy round figuring. Therefore, at 65mph on a level dry road with no wind, your car will achieve approximately 4 miles per kWh, or 84 miles of range. The Gid count should be about 6 when the car is dead (2% of 281), therefore 281 - 6 = 275 Gids to go 84 miles, or 3.27 Gids per mile.

3.27 Gids * 0.0758kWh = 0.248kWh used per mile at 65mph. Hope this helps with understanding the terms and parameters.

Again, all data is for a new, 70F or warmer battery. Things change drastically with cold and with degradation.

Re: Why not just display estimated number of kWh left?

Posted: Thu Nov 29, 2012 2:20 pm
by jlsoaz
TonyWilliams wrote: Hope this helps with understanding the terms and parameters.
Ok, thanks for the helpful response.

Re: Why not just display estimated number of kWh left?

Posted: Sun Dec 09, 2012 11:14 am
by jlsoaz
jlsoaz wrote:Maybe this has been answered, but at a quick search I do not see it. I don't dislike the 12 bars display, nor the estimated miles of range left, but why not add a way to view estimated useable kWh remaining?

(Come to think of it, I don't know that I've owned an ICV that just gave gallons, but my cars have generally been pretty basic. In any event, maybe it would be useful to see the estimated kWh.)
Having now started to find and toggle and use the display which gives me estimated average miles per kWh, and thus re-affirmed the value to me of thinking in terms of miles per kWh, I think that reduces the likelihood of an explanation being the some users won't get it.... it doesn't really matter... some users will really like it.