oz10k
Active member
What is the maximum (new car) AHr value from Leaf Spy for each battery size:
24 kWh
30 kWh
40 kWh
62 kWh
Thanks,
Ron
24 kWh
30 kWh
40 kWh
62 kWh
Thanks,
Ron
Leaf Spy AHr max by battery size
- Thread starter oz10k
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Jerryr
Well-known member
My new 2019 SL Plus w/62 kWh battery indicated 176.12 AHr a few hours after being fully charged overnight
Jerryr
Well-known member
LeafSpy reading voltage 402.68V
Useful info. Thanks.
oz10k
Active member
So it looks like the nominal numbers are:
24 kWh battery, max expected Ahr is 60.6
30 kWh battery, max expected Ahr is 77.5
40 kWh battery, max expected Ahr is 105.6
62 kWh battery, max expected Ahr is 167.6
Thanks.
24 kWh battery, max expected Ahr is 60.6
30 kWh battery, max expected Ahr is 77.5
40 kWh battery, max expected Ahr is 105.6
62 kWh battery, max expected Ahr is 167.6
Thanks.
alozzy
Well-known member
LeafG said:
Doubtful, I've never seen any documentation from Nissan directly that states the precise usable kWh of each pack.
The cutoff voltage on the high side is supposed to be 4.1V per module with the 24 kWh pack I think, but it seems that newer LEAFs have a cutoff voltage that's 4.2V (which explains JerryR's 402.68V)
So, on a 24 kWh pack, there are 24 modules consisting of 4 cells per module (2S2P), so max voltage would be 4.1V * 96 = 394V.
Similar math for the 40 kWh and 62 kWh packs, just change the max voltage to 4.2V
According to this article: https://pushevs.com/2020/04/04/comparison-of-different-ev-batteries-in-2020/:
40 kWh battery
Total battery capacity: 39,46 kWh
Usable battery capacity: 36 kWh (91 %)
Battery weight: 303 kg
Battery energy density: 130 Wh/kg
Cells: 192 (96s2p)
Chemistry: NCM 523
Ah would be kWh/V, so 98 Ah (39460 Wh/402.7V)
62 kWh battery
Total battery capacity: 62 kWh
Usable battery capacity: 56 kWh (90 %)
Battery weight: 410 kg (estimation)
Battery energy density: 151 Wh/kg (estimation)
Cells: 288 (96s3p)
Chemistry: NCM 523
Ah would be kWh/V, so 154 Ah (62000 Wh/402.7V)
However, none of that jives with what LeafSpy reports, so I'm not sure why it's higher in LeafSpy...
Take for instance JerryR's numbers:
V: 402.68
kWh: 60.1
Ah: 175.14 Ah
175.14 Ah * 402.68 V = 70.525 kWh!
Doesn't add up...
DougWantsALeaf
Well-known member
For the first 3 months you get access to 60kWh, then the bms pulls access away for 5-7% over next 3-12 months. It is an open debate as to whether or how much capacity the bms is hiding.
Not necessarily true. In my case, the initial Leaf Spy AHr reading was 175.15 at 64 miles on odometer and reading was 167.69 at 19,662 miles after 12 months of use. Readings after the last full charge were 165.36 AHr at 26,187 miles after more than 17 months of use.DougWantsALeaf said:
In comparison, the replacement battery in the 2011 had an initial AHr reading of 65.60 and the initial reading on the 2015 was 64.38 AHr. The readings after the initial full discharge and full charge in each case were: 2011 AHr=62.10, GIDS=266, Vmin=4.091, Vavg=4.099, Vmax=4.107; 2015 AHr=64.38, GIDS=292, Vmin=4.112, Vavg=4.121, Vmax=4.132; 2019 AHr=173.35, GIDS=721, Vmin=4.155, Vavg=4.161, Vmax=4.183.
alozzy
Well-known member
Does anyone know why the Ah, as reported by LeafSpy, seems to be higher than expected (based on the kWh capacity)?
Since the voltage varies between discharged and fully charged, the service manual uses 360 for the nominal voltage. If you divide the published capacity by 360, the results are close to the AHr reported by Leaf Spy for a new battery. In my cases 62,000 Wh/360 V=172.22 AHr and 24,000 Wh/360 V=66.67 AHr are close to what Leaf Spy reported when the batteries were new.alozzy said:
alozzy
Well-known member
Agreed, that math works...
So, I think you are saying that the nominal capacity, at 360V, is 62 kWh. If that's the case, then a fully charged pack has a capacity of:
172.22 Ah * 402.68V = 69.3.kWh
Correct?
So, I think you are saying that the nominal capacity, at 360V, is 62 kWh. If that's the case, then a fully charged pack has a capacity of:
172.22 Ah * 402.68V = 69.3.kWh
Correct?
alozzy said:
No. The voltage drops as current is drawn from the battery so you cannot use the voltage at full charge to calculate capacity.
alozzy
Well-known member
As a load (LEAF motor) is placed on the battery pack, current flows and the voltage drops, but this is true at any state of charge whenever a load exists...
So, isn't the nominal 360V state just as arbitrary as using 100% SOC? Surely the capacity of the pack at 100% SOC is what's most important?
I'm not trying to be difficult, just trying to understand how the "useable" kWh of the pack is actually determined from a "real world" perspective...
So, isn't the nominal 360V state just as arbitrary as using 100% SOC? Surely the capacity of the pack at 100% SOC is what's most important?
I'm not trying to be difficult, just trying to understand how the "useable" kWh of the pack is actually determined from a "real world" perspective...
You might just as well ask why "12 volt batteries" are rated that way, when they are more like "13 volt" batteries.
Stanton
Well-known member
Now that's a fact! My LiFePO4 12v battery sits ~13.2v.LeftieBiker said:
I concur with @GerryAZ's numbers: my lizard battery showed 66.14 Ahr when new (in 2016).
It's not a matter of voltage sag under load, the battery really does drop in voltage as it is discharged. It is a reflection of ion migration.alozzy said:
Ignoring stuff like Peukert's law, battery capacity is measured by discharging a battery from full to 'empty' at a low current, say 0.2C
The total energy is the average voltage * the (constant) current * the discharge_time.
A rubber band is a good analogy. It is a mistake to take the tension of the band at either full collapse or distension to figure out the work involved in pulling the band taut. You want the average tension along the stretch path.
