I want my 281!

[GaslessInSeattle]

would this work as a quick way to test pack health before buying: assure the car has been charged up to 100%, drive till 1 bar goes, note the miles, even better, recharge and measure how much it takes up? Tony, are there stats for this?

 

[GregH]

Well, first note that I'm comparing the 2013 LEAF SOC % specifically to the "Gid2" formula, while the straight Gid would be properly indexed to the SOC % of full = 24kWh = 100% = 300 Gid.

Yeah, I'm not considering the 2013 display or Gid2 although the practice of dividing Gids by 2.81 would net the same result, merely off by a factor of 2.81.

On a side note I wonder if the 0x55b % would make a good measure of how balanced a pack is?
ie, if it's "full" at 94% vs 97%...?

Turtle is likely tied to voltage, per Phil, which makes sense to protect the cells from over discharge.

Yeah, makes sense. Has anyone publicized the active CAN messages needed retrieve cell voltages?
Or do I need to eavesdrop on a transaction with a Nissan scan tool and pull it out myself..

 

[TonyWilliams]

Well, first note that I'm comparing the 2013 LEAF SOC % specifically to the "Gid2" formula, while the straight Gid would be properly indexed to the SOC % of full = 24kWh = 100% = 300 Gid.

Yeah, I'm not considering the 2013 display or Gid2 although the practice of dividing Gids by 2.81 would net the same result, merely off by a factor of 2.81.

Yes, straight Gid measurement to the SOC that you're looking at, since they both end at zero. You should divide by 300, not 281, so that 281 Gid equals the same as the SOC when new.

Hence, 281/300 = 93.66% which should also closely equal the SOC of about 94%.

The same will be true as it burns down, so that at turtle, 7/300 = 2.33% and so does SOC.

It's the difference that will be degradation.

However, to do the same with the 2013 LEAF % displayed SOC, use Gid2 data:

281 Gid = 100% Gid = 100% Gid2 = 100% SOC on new, non degraded 2013 LEAF display

7 Gid = 2.5% Gid = 0% Gid2 = 0% SOC on new 2013 LEAF

On a side note I wonder if the 0x55b % would make a good measure of how balanced a pack is?
ie, if it's "full" at 94% vs 97%...?

Turtle is likely tied to voltage, per Phil, which makes sense to protect the cells from over discharge.

Yeah, makes sense. Has anyone publicized the active CAN messages needed retrieve cell voltages?
Or do I need to eavesdrop on a transaction with a Nissan scan tool and pull it out myself..

It's out there. Maybe somebody will jump in...

 

[GregH]

would this work as a quick way to test pack health before buying: assure the car has been charged up to 100%, drive till 1 bar goes, note the miles, even better, recharge and measure how much it takes up? Tony, are there stats for this?

Best would be to get access to a CAN-bus scantool (there are many such devices/methods floating around here) and look at the Gids and reported SOC (in the 0x55b message), or convince the dealer to charge up the car to full and merely check the Gids (although in practice they may not wish to do this and/or you might not want to wait for it).

Based on what I've seen so far all the "new" 2012s are in similar shape (as one would hope!). This method might be more practical if you were looking at used cars.. especially used cars in warmer climates.

 

[GregH]

Has anyone publicized the active CAN messages needed retrieve cell voltages?

It's out there. Maybe somebody will jump in...

Knowing the Vmin and Vmax could be handy.
I've been driving an AC Propulsion eBox for the last week (borrowed from work) and it prominently displays Vmin on one of the main user screens. On our EDrive Prius conversions I used to graph Vmin vs Vavg (ie Vpack) vs Vmax at the top of the screen.. handy at very high and low SOCs.

 

[nogajim]

If you are using a GID meter, could you just monitor the GIDs remaining when it loses any charge bar and compare to Tony's original graph. I think the GIDs remaining when I lose my 10th bar are proportionately lower than they were last year, but I haven't checked how consistent it is.

 

[DaveinOlyWA]

monitoring GIDs gives you a guideline but my GID count bounces around pretty good. for a while now, I was seeing no more than 265-266 on full charge. then I go to Yokohama, gone for 6 days, come home and SO had only driven it 54 miles (had no other car so she just did not do much while I was gone) so, then I charged it up and got 271 this morning which is first 270 reading in over a month. I will assume its a fluke and will be back to my previous average but one thing is clear. if using GIDs to evaluate pack capacity, I would do at least 4-5 full charges daily before taking any reading too seriously

 

[GregH]

Awww Yeah!!

Finally, tonight Friday 2/22/13.. new car. Joulee 4? 1262 miles..

 

[surfingslovak]

Awww Yeah!!

Kudos, Greg, looking good!

 

[garygid]

From the bottom, left to right (I guess):

Min, Ave, and Max cell-pair Voltage?
GIDs, Pack Voltage
Real SOC %, Ave Pack Temp °F, and kW Out?
192 = ?

Mucho Cool work.

 

[GregH]

From the bottom, left to right (I guess):

Min, Ave, and Max cell-pair Voltage?
GIDs, Pack Voltage
Real SOC %, Ave Pack Temp °F, and kW Out?
192 = ?

Mucho Cool work.

Hey Gary! Thanks!
192 is just a counter that moves when the car is on or charging (was trying to catch post balancing charge events).
The 65.256 is an Ah counter I was playing with.. I reset it at full and it counts up then back down again on charge..
So this is actually -0.28Ah. Btw, I'm noticing in THIS car that the current sensor has about a 1A offset as compared
to Joulee3.. I hard coded a 1A offset in my SW (so it now more closely shows zero when the contactors open!) and
the Ah counter is working a lot better now.

 

[DaveEV]

So I finally assembled my LeafCAN over the weekend and am able to read GID counts. Here's what I've found after a couple 80% charges over the last 2 days and a 100% charge today (charged to 100% manually after charging to 80% on timer):

80% charge: 213 GID, 387V
100% charge: 260 GID, 394V

The 80-100% charge took 1h 11m and 3.986 kWh according to the Blink, but I didn't check today's 80% GID count to see if it matched the previous 2 days.

Appears a bit better than what the battery life model predicts - perhaps because of the cool weather? My seat-of-the-pants estimate of capacity is closer to the degradation model's estinate.

Are we collecting GID count database anywhere?

 

[QueenBee]

Are we collecting GID count database anywhere?

Tom from Plug In America is at: http://www.pluginamerica.org/surveys/batteries/leaf/index.php" onclick="window.open(this.href);return false;

 

[surfingslovak]

Tom from Plug In America is at: http://www.pluginamerica.org/surveys/batteries/leaf/index.php" onclick="window.open(this.href);return false;

Yes, thank you, I was going to recommend the PIA study as well.

 

[DaveinOlyWA]

I would take no less than 5 full charge readings on consecutive days and yes, I also believe cooler weather will give u a higher reading.

My LEAF is readjng between 275-278 and I bemiles
lieve my true reading should be 265-268 after 30,000 miles.

With changes in tires and random weather,. Its hard to quantifyany range loss. When i need more range, i just drive slower.with my hours, its pretty easy to do. Although not in LEAF right now, its 5:10 am and ha e been on the road for 90 mins...

 

[camasleaf]

My old Leaf is still at 281 after 28000 miles. It dropped to 278 in mid Feb but the readings came back up at 281 mid March.
I am so curios if the old one will go as far as the new one. I am waiting for the weather to improve where no heater or defog is needed, then put the back tires from the new Leaf to the front of the old Leaf and run both to turtle in parallel driving.
I have not done any maintenance on a car for over one year and my tools are getting rusty. Swapping the tires will be a good exercise, but I need to by a jack.

 

[garygid]

It seems a bit amazing that these Battery Packs in WA
appear to be "aging" so little, but perhaps the lack of exposure
to any significant amount of hot weather is the key.

 

[edatoakrun]

It seems a bit amazing that these Battery Packs in WA
appear to be "aging" so little, but perhaps the lack of exposure
to any significant amount of hot weather is the key.

Or perhaps the gid count is just as inaccurate as a measure of Wh in cooler climates, as it has been shown to be in hot climates?

camasleaf


My old Leaf is still at 281 after 28000 miles. It dropped to 278 in mid Feb but the readings came back up at 281 mid March.
I am so curios if the old one will go as far as the new one. I am waiting for the weather to improve where no heater or defog is needed, then put the back tires from the new Leaf to the front of the old Leaf and run both to turtle in parallel driving.
I have not done any maintenance on a car for over one year and my tools are getting rusty. Swapping the tires will be a good exercise, but I need to by a jack.

A lot of us are curious. Just as an aside, is there any way you could have the ~75k mile PNW LEAF also participate?

That is the comparative range test result I'd really like to see!

Please be sure to have battery pack temperatures of all your you test LEAFs equalized, especially while charging, and that CarWings is operational on all cars, before you make this test.

Without the regen kWh reports from CarWings, it is impossible, IMO, to measure variations in driver efficiency between LEAFs.

If you can control these, and all the other test variables well, your range test results should be extremely informative.

I personally am skeptical of the gid-indicated near-immortality of cool-climate LEAF battery packs, so my best guess (and it's only a guess) is that your "new" LEAF might display about 5% greater current available battery capacity than your old one does.

That ~5%, (+ or - ~2%) is the capacity loss I believe my LEAF probably has experienced over a similar period of time.

My loss was measured over a much lower differential of miles (~13,000, as opposed to your ~23,000) but my LEAF also probably has experienced considerably greater exposure to high battery pack temperatures.

 

[camasleaf]

Just as an aside, is there any way you could have the ~75k mile PNW LEAF also participate?

Do you mean TaylorSFGuy? Is he in the Seatlle area? I live in Camas Wa, I can get my wife's Leaf for a few hours, but to meet somewhere closer to Seattle and have the batteries at the same temperature will require overnight stay. Unless I find a reason to take my family to Seattle and let them stay overnight!? The batteries will be hot because of the 2-3 QC... not very likely I will be able to do it.

Please be sure to have battery pack temperatures of all your you test LEAFs equalized ...

I plan to charge in the garage to 80% on afternoon one a time on L2 (the hotter battery first), then about three hours before a test on next afternoon to charge both to 100% at the same time on L1.

We will try to use cruise control most of the time.

 

[edatoakrun]

Please be sure to have battery pack temperatures of all your you test LEAFs equalized ...

I plan to charge in the garage to 80% on afternoon one a time on L2 (the hotter battery first), then about three hours before a test on next afternoon to charge both to 100% at the same time on L1...

IMO, that should do it. If you watch the Battery temp bars during the test, and they both add a bar at about the same miles into the test, that should help to confirm they were both very close to the same temp when the final charge ended.

="camasleaf"

...We will try to use cruise control most of the time...

If you are saying this will be sufficient to eliminate variations in driver efficiency, I suggest again that you use CW to get the actual reports of regen of both LEAFs on the test, to take most of the diver efficiency guesswork out of the equation.

Of course, You'd expect the total regen used by two LEAFs to be very similar if they track the same route at the same speed at the same time, whether the cruise control was used or not.

But you may be trying to measure an extremely small difference between your two LEAFs, a battery capacity variation that could be as small as ~1% (as gid indicated) correct?

Why not reduce (or at least be able to account for the effects of) every known test variable, that you can?

CW will also give you a direct report of each LEAFs indicated kwh use on the test, as opposed to the less-accurate dash and nav screen m/kWh calculations.

The comparison of those CW kWh use reports, to those you will calculate from your gid meter, would be very informative, IMO.