Understanding Battery Condition w/o Using Leaf Spy

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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.
 
nlspace said:
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
 
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.
 
DougWantsALeaf said:
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 https://mynissanleaf.com/viewtopic.php?f=30&t=8802&p=572630&hilit=thailand+bars#p572630.

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

Agreed. But that is the effect of a weak cell, not a low capacity battery per se.
 
I'm old, absolutely not technical and would simply like to have an idea as to the condition of our 24 khw battery back without having to figure out which doggle or OBDI needs to be paired with a Leaf Spy or Leaf Spy Pro

The simplest method, that will give you a rough idea of capacity, is to drive your LEAF until you have 30% or less charge. Then, drive to a nearby L3 charger, note the state of charge, then plug in and charge until you add exactly 50% more charge, then immediately stop charging . Note the "kWh" displayed on the L3 charger then double that number to estimate the capacity of your pack in kWh.

Note that there are heat losses when L3 charging, so the actual capacity of the pack is less than the amount that the L3 charger provided. So, 95% of the L3 reported value is pretty close to the actual capacity.

So, for example, if the L3 charger reports adding 9.2 kWh then you would multiply 9.2 kWh x 2 = 18.4 kWh x .95 = 17.5 kWh pack capacity
 
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