nlspace
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Joined: Mon Jun 05, 2017 10:21 pm
Delivery Date: 06 Jun 2017

Re: Understanding Battery Condition w/o Using Leaf Spy

Wed Jul 21, 2021 2:50 pm

How does anyone know whether or not it will even drop below the last 2 Red bars? That might be a clue to the owner that your Pack is living on borrowed time.

If you just use the white bars, then the first bar drop is at 10/12, or 83%, or it has dropped a little over 15%, and the other bars are worth about 7%.

A Pack with only 15% capacity left would be next to useless. There wouldn't be enough voltage to stay out of Turtle. i would bet that when you hit the 2 red bars its game over.

SageBrush
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Re: Understanding Battery Condition w/o Using Leaf Spy

Wed Jul 21, 2021 3:32 pm

nlspace wrote:
Wed Jul 21, 2021 2:50 pm
A Pack with only 15% capacity left would be next to useless. There wouldn't be enough voltage to stay out of Turtle.
No lack of reports from people that drive down to a SoC of 1% in 24 kWh nominal LEAFS, so a capacity of ~ 200 Wh
2013 LEAF 'S' Model with QC & rear-view camera
Bought Jan 2017 from N. California
Two years in Colorado, now in NM
03/18: 58 Ahr, 28k miles
11/18: 56.16 Ahr, 30k miles
09/20: 54.3 Ahr; 38k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

nlspace
Posts: 407
Joined: Mon Jun 05, 2017 10:21 pm
Delivery Date: 06 Jun 2017

Re: Understanding Battery Condition w/o Using Leaf Spy

Wed Jul 21, 2021 3:53 pm

The "fuel" gauge SOC bars are independent of the Capacity bars--they may use the same units of energy, but they are not the same thing.

cwerdna
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Delivery Date: 28 Jul 2013
Location: SF Bay Area, CA

Re: Understanding Battery Condition w/o Using Leaf Spy

Wed Jul 21, 2021 4:29 pm

DougWantsALeaf wrote:
Wed Jul 21, 2021 1:51 pm
Bjorn has a video of one in Thailand with 1 or 2 bars.
Not super important, but if you have a pointer, that'd be nice. I pointed to a 3 bar car in Thailand at viewtopic.php?f=30&t=8802&p=572630&hili ... rs#p572630.

I know there's a guy in LA who posts on FB about his 3 bar car periodically w/videos and or pics.

'19 Bolt Premier
'13 Leaf SV w/premium (former)
'13 Leaf SV w/QC + LED & premium (lease over)

Please don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

SageBrush
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Re: Understanding Battery Condition w/o Using Leaf Spy

Wed Jul 21, 2021 5:36 pm

nlspace wrote:
Wed Jul 21, 2021 3:53 pm
The "fuel" gauge SOC bars are independent of the Capacity bars--they may use the same units of energy, but they are not the same thing.
Correct.
You missed the point that people frequently drive around with under 500 Wh of capacity remaining
2013 LEAF 'S' Model with QC & rear-view camera
Bought Jan 2017 from N. California
Two years in Colorado, now in NM
03/18: 58 Ahr, 28k miles
11/18: 56.16 Ahr, 30k miles
09/20: 54.3 Ahr; 38k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

nlspace
Posts: 407
Joined: Mon Jun 05, 2017 10:21 pm
Delivery Date: 06 Jun 2017

Words have specific meanings wrt batteries

Wed Jul 21, 2021 7:05 pm

They may be driving with only 500WH of ENERGY left in the tank, but that is not the CAPACITY of their Pack.

The Capacity is the size of the Pack; It gradually decreases one time over the long life period of the car.

The State of Charge shows the immediate energy available and changes daily up and down as you charge and drive.

i can see how it would be confusing to novices since both gauges are located so close next to each other.

This confusion is also the result of using make-believe units such as GIDs... :lol:

SageBrush
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Re: Words have specific meanings wrt batteries

Thu Jul 22, 2021 4:48 am

nlspace wrote:
Wed Jul 21, 2021 7:05 pm
They may be driving with only 500WH of ENERGY left in the tank, but that is not the CAPACITY of their Pack.
Obviously.

I am saying that if a person can drive with 500 Wh remaining and not be in Turtle, it does not matter if that state was reached by a LEAF battery with a high capacity and low SoC, or a low capacity and high SoC ... or any combination thereof.
2013 LEAF 'S' Model with QC & rear-view camera
Bought Jan 2017 from N. California
Two years in Colorado, now in NM
03/18: 58 Ahr, 28k miles
11/18: 56.16 Ahr, 30k miles
09/20: 54.3 Ahr; 38k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

WetEV
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Delivery Date: 16 Feb 2014
Location: Near Seattle, WA

Re: Understanding Battery Condition w/o Using Leaf Spy

Thu Jul 22, 2021 6:38 am

Drive the car until the battery is down to about 10%.

Plug into a charging station that records kWh delivered. Charge to 100%

The battery holds about the number of kWh delivered by the charging station.


There are a bunch of small effects that should be mentioned. Charging efficiency isn't exactly 90%, battery temperature should be at about 20C or 68F, metered kWh is likely off by a percent or two and I'm sure that there are more. But for a simple test, I don't think that this can be topped.

It is even better than LeafSpy.
WetEV
#49
Most everything around here is wet during the rainy season. And the rainy season is long.
2012 Leaf SL Red (Totaled)
2014 Leaf SL Red
2019 eTron Blue

SageBrush
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Re: Understanding Battery Condition w/o Using Leaf Spy

Thu Jul 22, 2021 8:26 am

WetEV wrote:
Thu Jul 22, 2021 6:38 am
Drive the car until the battery is down to about 10%.

Plug into a charging station that records kWh delivered. Charge to 100%

The battery holds about the number of kWh delivered by the charging station.


There are a bunch of small effects that should be mentioned. Charging efficiency isn't exactly 90%, battery temperature should be at about 20C or 68F, metered kWh is likely off by a percent or two and I'm sure that there are more. But for a simple test, I don't think that this can be topped.
I also think that this is a good approach. To clarify though, ~ 0.9*the kWh metered goes into the battery.

There is however a more convenient approach that comes close in accuracy: A home EVSE is going to have a pretty constant charge until 90% SoC. So plug in at a low SoC, charge up to ~ 90% and calculate. A check after an hour of charging should give a pretty good idea when 90% SoC will be reached. It does not have to be exact.

Example:
A 30 Amp EVSE at 240v is used
Start at e.g 12% SoC
Charge 3 hours to reach 91% SoC

6 kWh per hour for 3 hours reached the battery so 18 kWh = 79% charge, and a full charge would be 18/0.79 = 22.78 kWh

It bears mention that both of these methods, in addition to the capacity bars meter, are not including any usable reserve. For that you need LeafSpy.
2013 LEAF 'S' Model with QC & rear-view camera
Bought Jan 2017 from N. California
Two years in Colorado, now in NM
03/18: 58 Ahr, 28k miles
11/18: 56.16 Ahr, 30k miles
09/20: 54.3 Ahr; 38k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

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Nubo
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Delivery Date: 31 Oct 2014
Location: Vallejo, CA

Re: Words have specific meanings wrt batteries

Thu Jul 22, 2021 9:03 am

SageBrush wrote:
Thu Jul 22, 2021 4:48 am
nlspace wrote:
Wed Jul 21, 2021 7:05 pm
They may be driving with only 500WH of ENERGY left in the tank, but that is not the CAPACITY of their Pack.
Obviously.

I am saying that if a person can drive with 500 Wh remaining and not be in Turtle, it does not matter if that state was reached by a LEAF battery with a high capacity and low SoC, or a low capacity and high SoC ... or any combination thereof.
In practical application though it may have an effect. Turtle, iirc, is based on the voltage of the weakest battery module. As the pack ages the variation between modules tends to increase. By the time the battery is down to 3 bars (way past industry standard End of Service for Lithium batteries), it's quite likely that one or more weaker modules fall well below the pack average. Thus, turtleage could be looming at a higher kWH value compared to a newer healthy pack. At least that's my understanding. Someone correct me if I'm wrong.
I noticed you're still working with polymers.

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