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TonyWilliams
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Gid2 Percent Formula

Tue Dec 18, 2012 1:51 am

Ok, I don't know why this is bothering me, but I propose that we adjust our formula for Gids to read 100% at 281 Gid and 0% at 7 Gid.

This will more accurately reflect the 21kWh usable power, since the bottom about 300-400 watt hours are not usable, but included in our percentages.

(281 GIDs / 13.38) = 21kWh * 4 miles per kWh = 84 miles. But, as we know, any simple formula like that leaves miles remaining while the car in in turtle. Not wise.

Therefore, I want 7 Gid to be "zero", which also reflects a more accurate 50% useable energy level (a key metric to know when it's time to go home), hence the Gid2 formula:


(GID -7) / (281 - 7) = GID2


So that 281 GID = (1 * 21) = 21 * X miles per kWh = Y range in miles

And that 144 GID = (0.5 * 21) = 10.5 * X miles per kWh = Z range in miles

And so that 7 GID = (0 * 21) = 0 * X miles per kWh = 0 range in miles

The new 2013 will show 100% regardless of capacity, when fully charged, and show the following:


SOC% - "kWh usable" --Gid----Gid%---Gid2%---2013 dash % (2013 dash % data based on SOC%, not Gids)
95.x% -21.0--Full----281---100%---100%----100% (non-degraded at 70F; 21kWh usable)
------10.5--Half----144--51.2%----50%----50% (non-degraded at 70F; 10.5kWh usable)
95.x%-10.5--Full***--144--51.2%----50%----100% (***used 50% degraded at 70F; 10.5kWh usable)
------ 3.2---LBW----49---17.4%---15.3%----17%
------ 1.3---VLB----24----8.6%-----6.2%----8%
2.x%-- 0.0---Turtle --7-----2.5%-----0%-----(---)

NOTE: LBW and VLB are indexed to Gids, therefore those values won't match the SOC derived data of the 2013 dash % with a degraded battery.

Turtle is not indexed to Gids, therefore under a high load, like freeway speed, expect turtle at 7 or 8 Gids, and at extremely low power, as low as 4 Gids to Turtle.
Last edited by TonyWilliams on Fri Jul 19, 2013 1:40 am, edited 4 times in total.

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garygid
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Location: Laguna Hills, Orange Co, CA

Re: Gid2 Percent Formula

Tue Dec 18, 2012 4:24 am

Your range chart says that Turtle mode starts at GIDs = 4, which
would be below 0% in your proposal. Presumably Turtle mode
stops at about GID = 2,right?

Did you mean to propose 2 GIDs instead of 7 as the 0% point?

I suggest that we do not change the GID%, since it would be
confusing the old GID with the new GID2.

However, the formula for a "TONY" would be
TONY% = max( 0, (100 * (GID - 7) / (281 - 7) ) )
which would display 0% for the GID values less than 7.
See SOC/GID-Meter and CAN-Do Info
2011 LEAF, sold in 2015
2010 Prius, 2014 silver Tesla S
Nissan EVSE, mod to 240/120v 16A
PU: SDG&E
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Stoaty
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Re: Gid2 Percent Formula

Tue Dec 18, 2012 7:43 am

I'll see your GID and raise you two TONYS. Note that a TONY is worth less than a GID in the energy marketplace, but you have more usable TONYS than you do GIDS on a full charge so it all balances out in the end.
2011 Leaf with 62,000 miles given to Nephew
2013 Tesla Model S85 with 251 miles rated range at full charge
Leaf Spy Manual
Battery Aging Model Spreadsheet

FairwoodRed
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Location: Fairwood, WA

Re: Gid2 Percent Formula

Tue Dec 18, 2012 9:49 am

Does anyone use %GID’s? Wouldn’t it be a lot more useful to show useable kWh remaining? That way I can remove one step of my mental math…

vegastar
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Re: Gid2 Percent Formula

Tue Dec 18, 2012 11:03 am

I am used to the gids percentage, but I think that it would be good to have usable kW.h before turtle, like (gids - 7) x 0.08.
2011 Nissan LEAF since 2011-07-07, 151000 km on 2018-03-03, 7 bars, 37.9Ah.

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Ingineer
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Re: Gid2 Percent Formula

Tue Dec 18, 2012 12:49 pm

Not all Leafs start with 281 Gids of usable capacity, so for those cars it would still be off. Most new Leafs started with 279 from my research.

Why not simply use the Real SoC figure?

-Phil
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TomT
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Re: Gid2 Percent Formula

Tue Dec 18, 2012 3:22 pm

I have %Gid as one of the values displayed on my meter and I find it handy at times. I'm actually thinking of changing the code on a number of the values presented to correspond to my reduced maximum battery capacity and Gids. Currently I am displaying Gids, %Gids, remaining battery capacity in Kwh, voltage, Kwh in/out of battery, and extended fuel bars scaled to 0 at VLBW. I'd like to add real SOC% too, I believe...

FairwoodRed wrote:Does anyone use %GID’s? Wouldn’t it be a lot more useful to show useable kWh remaining? That way I can remove one step of my mental math…
59,991 miles/12 bars/289 Gids/68.54 AHr/101% SOH/101.64% Hx 7May15 w/ new Lizard (barely made the warranty).
71,770 miles/12 bars/256 Gids/59.04 AHr/88% SOH/87.92% Hx 3Mar16 at lease return.

Now driving a 2016 Volt Premier.

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garygid
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Re: Gid2 Percent Formula

Tue Dec 18, 2012 11:29 pm

As the battery capacity decreases, the Real SOC is
useless without a "tank" capacity to multiply by.

The Real SOC only shows the "fullness" of the tank,
not how much fuel is in the "shrunken" tank.
It suffers from the same problem that the "fuel-bar"
gauge has: even with a 60% capacity battery, it will
still indicate a fairly misleading "full".

I think of the GID% as a percentage of my car's
original fuel, and thus range (modified for conditions).
See SOC/GID-Meter and CAN-Do Info
2011 LEAF, sold in 2015
2010 Prius, 2014 silver Tesla S
Nissan EVSE, mod to 240/120v 16A
PU: SDG&E
Solar PV: 33 x 225W -> 7 kW max AC
To Sell: X-treme 5000Li EV motorcycle

LEAFfan
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Re: Gid2 Percent Formula

Wed Dec 19, 2012 12:09 am

garygid wrote:As the battery capacity decreases, the Real SOC is
useless without a "tank" capacity to multiply by.

The Real SOC only shows the "fullness" of the tank,
not how much fuel is in the "shrunken" tank.
It suffers from the same problem that the "fuel-bar"
gauge has: even with a 60% capacity battery, it will
still indicate a fairly misleading "full".

I think of the GID% as a percentage of my car's
original fuel, and thus range (modified for conditions).


+1 My LSGII only shows % which is based on the raw number 281. SoC % is only useful when the battery is new. Shortly after I got my meter, it hit 100% but never again.
2013 LEAF SV Del. 2/28/13
2013 LEAF World Record for Most Miles Driven On One Charge-188 miles/8.8 m/kW h
4.8 kW DC PV ($ .91/W fully installed)/ Dec., 2010

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TonyWilliams
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Re: Gid2 Percent Formula

Wed Dec 19, 2012 12:28 am

garygid wrote:Your range chart says that Turtle mode starts at GIDs = 4, which
would be below 0% in your proposal. Presumably Turtle mode
stops at about GID = 2,right?

Did you mean to propose 2 GIDs instead of 7 as the 0% point?


I do mean 7 Gid. Turtle is not an easy parameter to define with a strict Gid number. It can come on close to 8-9 Gid with high speeds (like we saw in Phoenix at 100km/h) or below 7 Gid with real easy driving (like the time i was 1.8 miles from my house... and made it home).

So, 7 Gid may or may not be Turtle, but it is the practical end of your trip.


However, the formula for a "TONY" would be
TONY% = max( 0, (100 * (GID - 7) / (281 - 7) ) )
which would display 0% for the GID values less than 7.


100 ((281 -7) / (281 - 7)) = 100%

100 ((144 -7) / (281 - 7)) = 50%

100 ((7 -7) / (281 - 7)) = 0%

Ok, I like it.

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