How to Check Battery Capacity, Degradation and Range

[buddyMac]

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]

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]

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]

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]

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]

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.

[bonro001]

Question on this, and this might not be the right tread. (It was as close as I could find)

We have a 2014 leaf with 36,662 miles and 10 dots. (Just went from 11 last week). To the question, is it the exception or experience of others that the battery does or does not trigger the warranty condition with normal driving? We live in Texas, quite a bit of heat here, wondering if I should be budgeting for a new battery.

Thanks!

[goldbrick]

How long have you had the car? The warranty on a 2014 is 5 years or 60k miles IIRC so it is very unlikely you will receive a warranty replacement pack on this car.

The capacity loss is fairly linear over time so you can plan ahead based on the past history of the car. It won't go to zero but it will lose capacity steadily. How much loss it can sustain before it no longer works for you depends on your needs. There is some seasonal variation in both range and loss due to temperature changes but overall the curve is more or less a straight line.

EV's with active thermal management systems (TMS) usually experience less battery capacity loss than a Leaf. You can research those or look into the after-market battery replacement options becoming available. Nissan doesn't seem to want to support battery replacement so I'd look there last, personally. But it all depends on how much future range you need and how much the car has today.

[LeftieBiker]

Question on this, and this might not be the right tread. (It was as close as I could find)

We have a 2014 leaf with 36,662 miles and 10 dots. (Just went from 11 last week). To the question, is it the exception or experience of others that the battery does or does not trigger the warranty condition with normal driving? We live in Texas, quite a bit of heat here, wondering if I should be budgeting for a new battery.

Thanks!

You could find out the "in service" date for the car to determine when the battery capacity warranty ends, but since you'd have to lose two more capacity bars ("dots") to get a warranty replacement, I'd forget about that.

[bonro001]

Thank you for the replies. Was thinking about it last night, I might be in the market for a new leaf in the next few years, might work the new battery into the deal. That way one of our kids get's a nice town car.