Battery labeled as 24kwh, but Leaf spy read BMS said 30kwh?

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jimmyaz

Member
Joined
Jul 3, 2022
Messages
6
Hi all,

I have a 2013 Nissan Leaf with 7bars and 56% SOH left. I have a salvaged battery from a junk yard, supposedly from a 2011-2012 (not quite sure) Leaf, it's Black on the outside, on the label it said 24kwh pack (295B03NF8A, Serial: 17CF000702). However, when I used your method of canbus and using Leaf spy to read the BMS (battery out of car). Leaf spy repeatedly indicate that this is a 30kwh on the cells balancing page. On top it said 30kwh AHr = 60.20 SOH=71.76% 385.72v HX=89.45%. Even if I set the "setting" of LeafSpy to 24kwh, once connected it will change to 30kwh.

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jimmyaz said:
Even if I set the "setting" of LeafSpy to 24kwh, once connected it will change to 30kwh.
This is normal LeafSpy behavior; you need to re-load the saved config data (once you set the year/model) every time you launch LeafSpy (at least I do with my 40 kWh pack). It's obvious from the AHr data that your pack is 24 kWh (around ~66 AHr new).
 
The battery is clearly fully charged (based upon the average cell voltages, overall pack voltage, and only 6 mV difference between min and max), but the SOC is shown as only 73.7%. A new 24 kWh battery has 80% of the capacity of a new 30 kWh battery. LEAF Spy thinks the battery is 30 kWh so it is showing the SOC as 73.7% while it appears that the actual SOC is about 94% (80% - 73.7% = 6.3%).
 
^Interesting. I would have thought the SOC was based entirely on cell voltages but somehow LeafSpy must be getting capacity information on the bus as well.

I'm assuming a 24kWh pack has the same number of cells as a 30kWh pack. That's right isn't it?
 
goldbrick said:
the same number of cells as a 30kWh pack. That's right isn't it?
I believe so. The cell count/configuration didn't change significantly until the introduction of the 40 kWh pack (which used a 4S4P config).
 
Stanton said:
jimmyaz said:
Even if I set the "setting" of LeafSpy to 24kwh, once connected it will change to 30kwh.
This is normal LeafSpy behavior; you need to re-load the saved config data (once you set the year/model) every time you launch LeafSpy (at least I do with my 40 kWh pack). It's obvious from the AHr data that your pack is 24 kWh (around ~66 AHr new).

Based on ahr, the pack is a 30 (82.34 new) if any of the other data is correct. Should have at least 2 missing capacity bars. Need more details really. As far as resetting anything, I have never done that and have plugged into several different cars with various capacities and all worked fine?
 
Stanton said:
jimmyaz said:
Even if I set the "setting" of LeafSpy to 24kwh, once connected it will change to 30kwh.
This is normal LeafSpy behavior; you need to re-load the saved config data (once you set the year/model) every time you launch LeafSpy (at least I do with my 40 kWh pack). It's obvious from the AHr data that your pack is 24 kWh (around ~66 AHr new).

That doesn't make sense though. Because I have hook up to other Leaf battery pack that was out of the vehicle just like this one and it never never ever automatically switch to 30kwh before... Only on this pack that it keep on switching to 30kwh... even if I reset setting to 24kwh.

Is the AHR is the amp hour that the BMS think the battery has degraded down to? Say if you have the 24kwh which is 66ah.... but now it's at 75% SOH, then it only have 49ah usable left?
 
DaveinOlyWA said:
Stanton said:
jimmyaz said:
Even if I set the "setting" of LeafSpy to 24kwh, once connected it will change to 30kwh.
This is normal LeafSpy behavior; you need to re-load the saved config data (once you set the year/model) every time you launch LeafSpy (at least I do with my 40 kWh pack). It's obvious from the AHr data that your pack is 24 kWh (around ~66 AHr new).

Based on ahr, the pack is a 30 (82.34 new) if any of the other data is correct. Should have at least 2 missing capacity bars. Need more details really. As far as resetting anything, I have never done that and have plugged into several different cars with various capacities and all worked fine?

Can not get a bar reading, this is battery out of the car... I am reading this as BMS reading, battery canbus directly to OBDII to Leaf Spy Pro.


But base on the 71SOH and 89HX values, it make sense and worth it to replace the 56SOH and 45HX battery currently in my Leaf right now right? worth the swap? Only thing worry me is it won't work without a Can splice? if it's indeed a 30kwh? It won't work without the can splice?
 
GerryAZ said:
The battery is clearly fully charged (based upon the average cell voltages, overall pack voltage, and only 6 mV difference between min and max), but the SOC is shown as only 73.7%. A new 24 kWh battery has 80% of the capacity of a new 30 kWh battery. LEAF Spy thinks the battery is 30 kWh so it is showing the SOC as 73.7% while it appears that the actual SOC is about 94% (80% - 73.7% = 6.3%).

So I read what you wrote 5 times and still can't wrap my head around it. :lol: haha... sorry.
 
Let me try again to explain what I think is happening:

I think the battery is truly a 24 kWh battery as the label shows. For whatever reason, Leaf Spy is interpreting it as a 30 kWh battery even though it is reading the AHr, SOH, and Hx correctly. It is probably also reading the stored energy (Wh) correctly so it shows SOC as 73.7% because the amount of stored energy is about 73.7% of the capacity of a 30 kWh battery. A 24 kWh battery can store 80% of the energy that a 30 kWh battery can store so the actual SOC of the 24 kWh battery is 73.7 / 0.8 = 92.1%. Leaf Spy will show about 94% SOC for a fully charged battery so that 24 kWh battery is not quite fully charged (or it is fully charged and has some minor capacity loss).
 
GerryAZ said:
Let me try again to explain what I think is happening:

I think the battery is truly a 24 kWh battery as the label shows. For whatever reason, Leaf Spy is interpreting it as a 30 kWh battery even though it is reading the AHr, SOH, and Hx correctly. It is probably also reading the stored energy (Wh) correctly so it shows SOC as 73.7% because the amount of stored energy is about 73.7% of the capacity of a 30 kWh battery. A 24 kWh battery can store 80% of the energy that a 30 kWh battery can store so the actual SOC of the 24 kWh battery is 73.7 / 0.8 = 92.1%. Leaf Spy will show about 94% SOC for a fully charged battery so that 24 kWh battery is not quite fully charged (or it is fully charged and has some minor capacity loss).

So, so let say it's a 24kwh. But the AHR and SOH doesn't seems to match though. Isn't the SOH % is directly related to the number of AH the pack have left?

I have check my other Nissan Leaf (battery still in car). example, 82% SOH = 54AHr... Which is right 82% of original rated 66AH (24kwh) = 54AHr.

But this pack said 71% SOH but 61ah.
 
Stanton said:
jimmyaz said:
It won't work without the can splice?
No matter what you believe about the capacity of the pack, the above statement is true once you do the battery swap.

I thought if you replaced a 24kwh pack with a 24kwh, it's a direct replacement and you only have to use Leaf Spy Pro to reset and it should work?
 
jimmyaz said:
Stanton said:
jimmyaz said:
It won't work without the can splice?
No matter what you believe about the capacity of the pack, the above statement is true once you do the battery swap.

I thought if you replaced a 24kwh pack with a 24kwh, it's a direct replacement and you only have to use Leaf Spy Pro to reset and it should work?
It's possible, since you have a 2013 (not a ZE0)...but I don't have direct experience with that scenario.
 
jimmyaz said:
DaveinOlyWA said:
Stanton said:
This is normal LeafSpy behavior; you need to re-load the saved config data (once you set the year/model) every time you launch LeafSpy (at least I do with my 40 kWh pack). It's obvious from the AHr data that your pack is 24 kWh (around ~66 AHr new).

Based on ahr, the pack is a 30 (82.34 new) if any of the other data is correct. Should have at least 2 missing capacity bars. Need more details really. As far as resetting anything, I have never done that and have plugged into several different cars with various capacities and all worked fine?

Can not get a bar reading, this is battery out of the car... I am reading this as BMS reading, battery canbus directly to OBDII to Leaf Spy Pro.


But base on the 71SOH and 89HX values, it make sense and worth it to replace the 56SOH and 45HX battery currently in my Leaf right now right? worth the swap? Only thing worry me is it won't work without a Can splice? if it's indeed a 30kwh? It won't work without the can splice?

Ah, I see. Well, it should be obvious that the battery out of the car is causing an error. Based on general LEAF Spy readings, it does indicate a 30 kwh pack since the ahr aligns with the nearly 30% degradation.

So you either have that or the battery out of the car is messing with LEAF Spy's ability to read it.

As far as swapping in another battery, you need something translate the pack. Even a 24 to 24 needs this iirc.
 
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