buddyMac
Posts: 6
Joined: Thu Mar 21, 2019 8:29 am
Delivery Date: 21 Mar 2019

Re: How to Check Battery Capacity, Degradation and Range

Thu Mar 21, 2019 8:43 am

Good Day,

I am evaluating a 2016 SV with 30 kwh batt. The Leaf Spy tells me it has 83% SOH. Should I worry that it is that low with 14000 miles and all battery bars showing? Thanks

AHR - 66.29
SOH = 83.4
394.24 volts
hx=61.29

goldbrick
Posts: 426
Joined: Tue Aug 01, 2017 3:33 pm
Delivery Date: 01 Aug 2017
Leaf Number: 311806
Location: Boulder, CO

Re: How to Check Battery Capacity, Degradation and Range

Thu Mar 21, 2019 10:41 am

That does sound pretty bad but it depends on whether or not the car has had the 'software update' applied to the BMS.

The 30kWh cars were showing a lot of early degradation and Nissan claimed the problem was that the BMS software was miscalculating the battery capacity. Nissan issued a free software update that supposedly corrected this problem. The reported SOH of the affected cars was much better afterwards.

For example, my 2017 S was at 92% SOH after 8 months. I had the BMS software update done at the 12 month 'battery check' and the SOH is at 96+% SOH now after 20 months. My real world range seems to verify the SOH levels I see today.

The owner should know whether the BMS update has been done. If it hasn't the SOH will probably increase afterwards. If it has been done then that battery is probably on its way towards a warranty replacement, although that all depends on how it is used and cared for in the time remaining until the warranty expires (8 years or 100,000 miles).

buddyMac
Posts: 6
Joined: Thu Mar 21, 2019 8:29 am
Delivery Date: 21 Mar 2019

Re: How to Check Battery Capacity, Degradation and Range

Thu Mar 21, 2019 10:52 am

Thanks for the reply,

I don't know about treatment by the owner previous owner. But, the carfax listed a maintenance item as 'reprogrammed the computer' ( sorry don't have the exact wording). I asked my local dealership if that was suspicious, he said the comment could have been anything. So, I think I will spring for the full check-up at the dealership and see if they come up with the same number, taking into account sources that could skew it. Or perhaps other numbers that may call the SOH number into question.

goldbrick
Posts: 426
Joined: Tue Aug 01, 2017 3:33 pm
Delivery Date: 01 Aug 2017
Leaf Number: 311806
Location: Boulder, CO

Re: How to Check Battery Capacity, Degradation and Range

Thu Mar 21, 2019 12:53 pm

I wouldn't put too much faith into what the dealer tells you since they often aren't really savvy about EV's and their main motivation is to sell cars.

Do you know where the car is from? The worst thing to do to a Leaf (or any EV really) is to store it at high temperatures and very high SOC. Very low SOC (< 10%) is also hard on the battery but most people will plug in at that point rather than let the car just sit.

If the car is from a hot area (AZ, FL, TX, etc) it is possible that those readings are accurate. If so, you can gamble that the battery will hit its warranty replacement level before the warranty expires but that is a risk. In that case, you can make a strong argument for a lower price.

At 83% SOH it should be dropping to 11 bars very soon. It is also possible to 'reset' the BMS which will temporarily restore the car to 12 bars until the BMS has time to recalibrate itself to the existing battery conditon. That is a pretty shady practice and I would be very leery of buying a car in that condition.

buddyMac
Posts: 6
Joined: Thu Mar 21, 2019 8:29 am
Delivery Date: 21 Mar 2019

Re: How to Check Battery Capacity, Degradation and Range

Fri Mar 22, 2019 11:51 am

Well, the dealer said that the update ( one to fix reporting lower battery health than it really is ) has already been applied to the vehicle. So, the 83% is correct.

This vehicle was out of California, in a metro area, I believe.

I will decide over the weekend if that low number is enough to pass on this particular vehicle.

I don't suppose there is a chance that cycling the battery a few times might change that number. Although I have to decide before the 27th.

Thanks for the help.

goldbrick
Posts: 426
Joined: Tue Aug 01, 2017 3:33 pm
Delivery Date: 01 Aug 2017
Leaf Number: 311806
Location: Boulder, CO

Re: How to Check Battery Capacity, Degradation and Range

Fri Mar 22, 2019 12:00 pm

It does sound like that is the correct reading for this car. That doesn't mean the car is useless but it should be valued for what it is. The first bar will drop any day and you will have an 11 bar car. That is still about the same range as a brand new 24kWh car but it is far from the original 30kWh capacity.

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