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TonyWilliams
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Re: Report Your Gid Number at 100% Charge

Thu Apr 05, 2012 4:03 pm

Ingineer wrote:
surfingslovak wrote:Yes, and please don't forget losses, such as heat developed when storing and retrieving energy from the battery, and the energy lost during cell balancing. I believe that both are unaccounted for, and they will be missing from the equation if you assume 80 Wh will be going in and out of the battery. Sure, you can ignore them, and adjust for that error later, but this energy is lost, and you will ultimately see the effect one way or another. Even without instrumentation. Yes, it's old school and much tougher, but if there a sizable error, it can and will be detected by a careful observer.
The watt-hours are "usable output", so they are corrected. (constantly in fact, as battery parameters are always in flux)

-Phil
I think we not going to come to a meeting of the minds on this!!!

I'll part with this thought; if you drive, as I have done, from fully charged to empty, the data compiled from the dash data and the Gid count that we have been observing since last fall does not meet the 80 threshold.

Obviously, it does in your more advanced observations; that is without question by anybody, myself included.

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Ingineer
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Re: Report Your Gid Number at 100% Charge

Fri Apr 06, 2012 2:56 am

I trust what I see on the CAN bus from the Battery ECU (LBC) and of course on my instrumentation, but I definitely don't trust data I see from the VCM and the CM/Nav. They are doing some strange things there with this data I am reading from the Battery ECU. You don't trust half of the data, such as the GoM, but you do trust the miles/kWh figure? I haven't yet figured out how/why it's wrong, but like you, I tend to stop looking at things I don't trust.

If you want to trust the miles/kWh figures from the CM/Nav, which of course are calculated by using figures over the CAN bus exclusively from the Battery ECU, of course you can. If you insist, then I have to agree to disagree.

Maybe when you get your LEAFSCAN you'll come around... :)

Until then the only hard data anyone can really have is miles per wall kWh, as long as the odometer is trusted. (Unless you want to believe the Gids)

-Phil
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surfingslovak
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Re: Report Your Gid Number at 100% Charge

Fri Apr 06, 2012 9:32 am

Ingineer wrote:I trust what I see on the CAN bus from the Battery ECU (LBC) and of course on my instrumentation, but I definitely don't trust data I see from the VCM and the CM/Nav. They are doing some strange things there with this data I am reading from the Battery ECU. You don't trust half of the data, such as the GoM, but you do trust the miles/kWh figure? I haven't yet figured out how/why it's wrong, but like you, I tend to stop looking at things I don't trust.

If you want to trust the miles/kWh figures from the CM/Nav, which of course are calculated by using figures over the CAN bus exclusively from the Battery ECU, of course you can. If you insist, then I have to agree to disagree.

Maybe when you get your LEAFSCAN you'll come around... :)

Until then the only hard data anyone can really have is miles per wall kWh, as long as the odometer is trusted. (Unless you want to believe the Gids)
Interesting, to say the least. I'm not insisting on anything, and while I expected to see losses, the size of the discrepancy between energy in and energy of the battery surprised me. If you believe in Gids and the energy economy gauge of course.

Since you mentioned the odometer and kWh out of the wall. Both are somewhat inaccurate themselves. That being said, we are seeing an overall efficiency of 85%, if the energy economy gauge can be trusted, and we based a lot of the values, including the effective usable battery size on that. This value has been in turn used by many others, including Nissan (in their recent TB).

Here is an interesting factoid. When I compare the ActiveE and the Leaf, I see about 7% difference in energy economy when driving on flat ground at a constant speed. This could be easily explained by inaccurate or inconsistent energy economy gauge in both vehicles. However, it could be representative of a real difference in energy economy as well, and I believe I see some of this in the range figures I'm getting, as inaccurate as the methods I'm using are.

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TonyWilliams
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Re: Report Your Gid Number at 100% Charge

Fri Apr 06, 2012 9:45 am

Ingineer wrote:
If you want to trust the miles/kWh figures from the CM/Nav, which of course are calculated by using figures over the CAN bus exclusively from the Battery ECU, of course you can. If you insist, then I have to agree to disagree.

Maybe when you get your LEAFSCAN you'll come around... :)

Until then the only hard data anyone can really have is miles per wall kWh, as long as the odometer is trusted. (Unless you want to believe the Gids)

-Phil
Oh, I'm confident that I will love LEAFSCAN, and of course, we both agree that driver presented data is whacked. From the viewpoint of my range chart, however, we have to work with the tools presented. If I discount everything, there's not much to work with. As a percentage of LEAF drivers, few will have a Gidmeter or a LEAFSCAN.

So, the GoM and CarWings were rightly immediately eliminated from consideration. Even the fuel bars are a bit mushy, but two measurements have held somewhat consistent; the two battery warnings, and for those of us with a Gidmeter, the corrected watt/hour measurement at those landmarks. So, I put a good deal of reliance on those two points, and the Gids. Currently, no other tools exist to do that.

The other piece of the puzzle, of course is miles and economy. We know CarWings isn't accurate, but even if the odometer is not accurate, it should somewhat consistent over the fleet. The same should be somewhat true of the economy meter. Granted, the resolution is crap, and all the games of "processed" data, as opposed to raw data, come in play.

But, without that, we quickly run out of tools to determine the most readily available information to determine range. As is, we can do a remarkable job in comparison to the fleet of engineers who pieced together the GoM.

So, back to the original question. Until such time as more refined, accurate data is available, with the aforementioned tools at our disposal, a Gid appears to fall in the 75 watt/hour range. That merely amplifies the inaccuracies of the economy meter that we use to calculate that number, but again it's consistent (somewhat) until such time that new tools arrive.

For those that never acquire those tools, and must rely on the LEAF presented displays, it's not even a factor, because they won't have a Gidmeter to consider.

By the way, I'll probably make a new range chart dedicated specifically to the LEAFSCAN, since none of the data, like battery capacity, Gid value, etc, will work from the existing chart.

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TonyWilliams
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Re: Report Your Gid Number at 100% Charge

Fri Apr 06, 2012 9:50 am

surfingslovak wrote:Here is an interesting factoid. When I compare the ActiveE and the Leaf, I see about 7% difference in energy economy when driving on flat ground at a constant speed. This could be easily explained by inaccurate or inconsistent energy economy gauge in both vehicles. However, it could be representative of a real difference in energy economy as well, and I believe I see some of this in the range figures I'm getting, as inaccurate as the methods I'm using are.
Try at different speeds, and see if the delta in economy changes. I suspect the a larger delta at higher speeds will be attributed to aerodynamics, and a more constant economy delta will be the weight delta.

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DaveEV
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Re: Report Your Gid Number at 100% Charge

Fri Apr 06, 2012 9:51 am

surfingslovak wrote:Here is an interesting factoid. When I compare the ActiveE and the Leaf, I see about 7% difference in energy economy when driving on flat ground at a constant speed. This could be easily explained by inaccurate or inconsistent energy economy gauge in both vehicles. However, it could be representative of a real difference in energy economy as well, and I believe I see some of this in the range figures I'm getting, as inaccurate as the methods I'm using are.
Either way - it can easily be confirmed by taking measurements from the wall on identical trips..

edatoakrun
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Re: Report Your Gid Number at 100% Charge

Fri Apr 06, 2012 11:53 am

TonyWilliams wrote:...two measurements have held somewhat consistent; the two battery warnings, and for those of us with a Gidmeter, the corrected watt/hour measurement at those landmarks....
="TonyWilliams"]...Of all the crazy displayed data that Nissan has endowed upon us, the two separate battery warnings are consistently at fixed battery performance values...
http://www.mynissanleaf.com/viewtopic.p ... 0&start=10" onclick="window.open(this.href);return false;

Are the LBW and VLBW, less "fixed" today, than they were yesterday, Tony?
no condition is permanent

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surfingslovak
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Re: Report Your Gid Number at 100% Charge

Fri Apr 06, 2012 12:07 pm

drees wrote:Either way - it can easily be confirmed by taking measurements from the wall on identical trips..
Yes, in theory. In practice, reality will interfere, and you won't get the same readouts. There are too many variables to consider.

On my last 100-mile trip, I only achieved 103 miles of range, versus 107 on a nearly identical trip in December. Energy economy was the same: 5.1 kWh. Did my battery degrade 4% in three months? I doubt it, since my Gid reading was about the same on both occasions. And I have yet to get the same kWh number from the wall when I drive the car to turtle, and then charge to full. There are several others that have performed the same exercise, with similar results. It's never the same number. Sometimes not even close.

vegastar
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Re: Report Your Gid Number at 100% Charge

Fri Apr 06, 2012 12:32 pm

Yesterday results:
80% charge 231 gids@386V
100% charge 270 gids@392V
Today:
80% charge 231 gids@386V
100% charge 279 gids@393V
2011 Nissan LEAF since 2011-07-07, 151000 km on 2018-03-03, 7 bars, 37.9Ah.

essaunders
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Re: Report Your Gid Number at 100% Charge

Fri Apr 06, 2012 1:47 pm

TonyWilliams wrote:We know CarWings isn't accurate,

Tony (or anyone else)

What is the basis for current (fully software-updated LEAF) carwings inaccuracy? Is it simply the ~2.5% delta that I observed in the reported mileage? I understand the original cars (pre=update) had a pretty wild Carwings data set, but what is the current data showing the current issue?

(sorry - I've searched over MNL for this, but never found an answer that explains this)

I ask this as I don't have a GID-meter (waiting for LEAFSCAN) yet so I have only the in-dash and CW to review....

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