Post Your Battery Degradation Results

[lorenfb]

Just waiting for my second bar to drop.

2013 with 53,144 miles, LeafSpy: 49.756 AHr, SOH 74%, Hx70.30% as of 08/20/2018

A huge drop in capacity since March when I had 55AHr and 84%, then again, we had a lot of 90 degree plus days this summer.

Basically the same as my Leaf at 67K now.

[azguy]

odo=27685 mi 9QC's & 1715 L2 SOH=82.38% AHr=51.16

[Reddy]

Update: just lost my second bar today. Build date is 03/13 so it's a canary.

Well, that definitely confirms it for me., though I had little reason to doubt everyone's reports. I have friends in Seattle with a 2011, just like me. They have less battery degradation than I with 2x the mileage (Seattle vs hot Eastern WA). I also have a friend here in Kennewick with a 2013 (June build) who has >50,000 mi and has not lost a bar yet (whereas I'm at 9-bars).

[brycenesbitt]

Is there a public database of battery results for the Leaf? Something like:
http://www.mynissanleaf.com/viewtopic.p ... 34#p535245

[MrNicG]

2012 Leaf SL bought used in July of 2018. (I actually traded straight across for it for an old run-down Ridgeline)

SOH: 60.79%
Hx: 38.76
Bars: 8
Range: 45 miles
Rate of degradation: .04% per day.

I've been trying to find out what is causing my battery to degrade so fast. At this rate, it will lose about 12% over the next year, which seems to be faster than the already quick rate I have read online. I am starting to think that Nissan may know something causing the Leaf battery to degrade so much faster than every other EV out there. Based on my analysis of the LeafSpy logs, it sort of looks like as the 12v battery gets low and the traction/HV battery needs to top it off, the traction/HV battery takes a hit to SOH. A couple of times since I bought the car it has gone for 3 days with no loss in SOH.

[WetEV]

I've been trying to find out what is causing my battery to degrade so fast.

Where are you located? What is the local climate like? What kind of driving do you do? What kind of charging?

LeafSpy reads the Battery Management System (BMS). The BMS estimates of capacity vary for reasons that have nothing to do with capacity. Short term trends are not meaningful.

By driving and charging in a specific way I was able to raise my LeafSpy SOH numbers by more than 12% in a few weeks. I've been able to lower the numbers by about 3% by driving and charging in a completely different way.

There are many different explanations what what you are seeing. The first is that you live in a very hot place and the battery is losing capacity quickly. The second is that you are doing awful things to the battery. The third is that your driving is different than the last owner's, and the BMS estimates are changing without any real change in battery capacity. And there are probably more.

There also seems to be a seasonal cycle in reported SOH. Drops in the summer, and recovers some but not all of that in the fall/winter. Also not a real change in battery capacity, as capacity is lower at cooler temperatures.

[MrNicG]

I've been trying to find out what is causing my battery to degrade so fast.

Where are you located? What is the local climate like? What kind of driving do you do? What kind of charging?

I live in central Florida. The average temp in my area is about 85 degrees. Humidity is normally high. I normally drive fairly conservatively. My commute is 10 miles each way, with a top speed of about 45MPH. It is almost an equal mix of back streets, going 35 and boulevard going 45. According to LeafSpy, the SOH seems to only drop when it is parked, or perhaps when it is started after being parked. I charge with the stock Level 1 EVSE.
I started using a trickle charger for the 12v when the car is parked and I am going to monitor that for a while and see if it helps. Also, I was wondering if the method of starting the car makes any difference, so instead of single press to start, I am pressing once to power up and then pressing the second time to switch into Go mode.

[lpickup]

Also, I was wondering if the method of starting the car makes any difference, so instead of single press to start, I am pressing once to power up and then pressing the second time to switch into Go mode.

I am sure it doesn't matter, but why do you do this? Are you saying that you press the power button without your foot on the brake, and then step on the brake and press it again? Just press on the brake and push start once.

[marcelg]

I've been trying to find out what is causing my battery to degrade so fast.

Where are you located? What is the local climate like? What kind of driving do you do? What kind of charging?

I live in central Florida. The average temp in my area is about 85 degrees. Humidity is normally high. I normally drive fairly conservatively. My commute is 10 miles each way, with a top speed of about 45MPH. It is almost an equal mix of back streets, going 35 and boulevard going 45. According to LeafSpy, the SOH seems to only drop when it is parked, or perhaps when it is started after being parked. I charge with the stock Level 1 EVSE.
I started using a trickle charger for the 12v when the car is parked and I am going to monitor that for a while and see if it helps. Also, I was wondering if the method of starting the car makes any difference, so instead of single press to start, I am pressing once to power up and then pressing the second time to switch into Go mode.

Do you regularly charge the vehicle over 80%? From what I've read, high temps + high state of charge is a primary cause of accelerated degradation. Batteries that are kept between 20-80% get many more cycles than those that are used 10-100%.

[MrNicG]

Also, I was wondering if the method of starting the car makes any difference, so instead of single press to start, I am pressing once to power up and then pressing the second time to switch into Go mode.

I am sure it doesn't matter, but why do you do this? Are you saying that you press the power button without your foot on the brake, and then step on the brake and press it again? Just press on the brake and push start once.

I was curious if it might be causing some power draw spike that was hurting the battery. I think I've just gotten carried away with things to try.