Figuring Out the Actual Battery Size

My Nissan Leaf Forum

Help Support My Nissan Leaf Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

LarryKaplan

Active member
Joined
Sep 14, 2019
Messages
35
Not sure which forum to post in, so I posted twice, sorry.

Question About Calculating Actual Battery Size Using LeafSpy: I bought a battery from a place that said it was a "new" 30 kWh offloaded by a dealer who was getting rid of inventory.

I went out and got LeafSpy to see what was up. It says the SOH is 80% but the GOM shows 12 bars, so maybe there is a problem with the car (2012) reading the battery. So I will assume LeafSpy is right, and I will have to deal with the shop that said it was new -- ask for a partial refund or something.

But what I would really like to figure out is if it really is a 30. There must be a way to extrapolate the original size using the various numbers from LeafSpy -- Ahr, remaining kWh at current SOC, etc? Anybody know the right formula? Thanks in advance.
 
Not sure which forum to post in, so I posted twice, sorry.

Question About Calculating Actual Battery Size Using LeafSpy: I bought a battery from a place that said it was a "new" 30 kWh offloaded by a dealer who was getting rid of inventory.

I went out and got LeafSpy to see what was up. It says the SOH is 80% but the GOM shows 12 bars, so maybe there is a problem with the car (2012) reading the battery. So I will assume LeafSpy is right, and I will have to deal with the shop that said it was new -- ask for a partial refund or something.

But what I would really like to figure out is if it really is a 30. There must be a way to extrapolate the original size using the various numbers from LeafSpy -- Ahr, remaining kWh at current SOC, etc? Anybody know the right formula? Thanks in advance.
 
I think LeafSpy will show you the battery part number after you enable the diagnostics page using the setup menu. I don't know the details offhand but I'm sure you can find them. This might require LeafSpyPro (the paid version).
 
I was referring to the EV HV battery number that is displayed in the service menu. The service menu must first be enabled in settings. Then the EV HV battery number is 3rd from the bottom, on my display at least.

My car shows part 293A0 version 4NP4C, which are the last digits as "Controller Battery, Part Number: 293A0-4NP4C". This number is almost certainly a 30kWh part since that is what is in my Leaf.

I don't know what number would be relevant for a 24 kWh pack but I think it would be different. A quick search on parts.nissanusa.com makes me think it might be 293A0-9RB3A, but that's a swag.

On closer look, these part numbers appear to be the battery controllers, not the actual battery pack so maybe they are not so useful.
 
I charged to 100% last night. As you know, the onboard charger will not always take the battery to 100% -- in my case, it charged to 90%. At 90% charge, LeafSpy says I have 16 kWh SOC on the battery, or 46 Ah. Extrapolating from that (16 divided by .9), I get about 18 kWh fully charged to 100%.

LeafSpy says the SOH is approximately 80% (52 Ah). Again with simple math, if I divide 18 by .8, I get 22.5. If the car is holding back 1.5 kWh to protect the battery, which is the typical amount, that would tell me I have a 24 kWh battery in the car. NOT a 30 kWh. The odd thing is that the GOM says I have a full 12 bars SOH. If it was accurately reading the battery, it would show only 10 or 11 bars. Could it be that the car thinks there is a 24 kWh battery in there, while LeafSpy is reading the true battery size? Which could well be 30?
 
I charged to 100% last night. As you know, the onboard charger will not always take the battery to 100% -- in my case, it charged to 90%. At 90% charge, LeafSpy says I have 16 kWh SOC on the battery, or 46 Ah. Extrapolating from that (16 divided by .9), I get about 18 kWh fully charged to 100%.

LeafSpy says the SOH is approximately 80% (52 Ah). Again with simple math, if I divide 18 by .8, I get 22.5. If the car is holding back 1.5 kWh to protect the battery, which is the typical amount, that would tell me I have a 24 kWh battery in the car. NOT a 30 kWh. The odd thing is that the GOM says I have a full 12 bars SOH. If it was accurately reading the battery, it would show only 10 or 11 bars. Could it be that the car thinks there is a 24 kWh battery in there, while LeafSpy is reading the true battery size? Which could well be 30?
 
The Battery Management System (BMS) may have been reset. It would appear that you have been deceived.

The two identical topics have been merged into one.
 
They might be able and willing to tell you that a reset had been done, but I wouldn't count on it. More like some dealers are able to diagnose, some are willing, but there isn't much overlap between those two groups.
 
LarryKaplan said:
Yeah, maybe. Would taking the car to a Nissan dealer for a diagnostic do any good? Thanks.
Not willingly (once you tell them you've replaced the battery outside of a dealer), and certainly not for free.
You didn't say what model year Leaf you have, but you need to select the correct battery type in LeafSpy (on one of the "settings" screens). Only then can you trust the AHr readings (among other things)...but I suspect you got a pretty degraded battery pack (and I wouldn't touch a 30kWh pack at any price).
Sorry if that's not what you wanted to hear.
 
Another Question: I've been told that there are 2 battery management systems on a LEAF -- one in the battery pack itself and one onboard the car. True? And if true, which one is LeafSpy reading? If LeafSpy says an aftermarket installed battery SOH is 80%, for example, can I trust that as accurate? It’s already in the car so I’m using the OBD port to connect. Thank you.
 
When the BMS is reset, LeafSpy gets fooled as well, at least for a while. The exact length of time that it takes LeafSpy to start reading the pack accurately isn't known, and it apparently varies a bit, ranging from a few weeks to about 6 months. My guess is that it depends on how much the car is driven after the reset.
 
Back
Top