What four bars down looks like

by Ernie Hernandez on May 29, 2017

Battery degradation in a 2012 Nissan LEAF

Battery degradation exists in electric cars, just as it does in mobile phones and laptops, but many people that are not familiar with electric cars have no idea what that is, or what it means. This article will help to fill in that knowledge gap.

First, let’s provide you with some background information. The above image was taken on May 28, 2017. This is a 2012 model Nissan LEAF SV that was sold originally, according to CARFAX, on January 11, 2013 and was built on July 21, 2012. It was sold in Southern California, and seems to have been driven in SoCal during its three year lease. I bought the car from a San Diego Nissan dealership in February of 2016 after it had come off lease. When I bought it, the car had 33,986 miles on it. So with this basic information in hand, you can see that we put under 10,000 miles on it in a fifteen month period. One other bit of important information – when we bought it, after only three years and roughly 34,000 miles it had already lost three bars of battery capacity. So that’s where we started with this car. It lost the fourth bar about fifteen months after we bought it.

If you look at the right side of the image, you will see two small red segments at the bottom right with six white segments above them. These are the battery capacity bars that LEAF drivers talk about. When this car was new, there were ten of those white segments above the red ones for a total of twelve bars. I will talk more about this battery degradation shortly. Just to the left of that, you can count 12 blue and white bars around the big 57 miles indicator. So when the car was new, the little white segments on the right would have matched all of the blue and white bars just to the left of them. These four missing white segments are what LEAF owners talk about when they talk about battery degradation. The longer blue and white bars are like a gas tank indicator on a gas-powered car. When full there are twelve bars, and as you use up the electricity stored in the battery, the blue and white bars start dropping off just like a fuel-tank indicator would. You will also see the big range remaining indicator count down toward empty.

As can be seen from the above image, the vehicle range as reported by the range remaining indicator is 57 miles at this point. The range remaining increases when placed in the Eco mode. Here is what it looks like in Eco.

So in this case, you can see that the Eco mode provides roughly an additional nine percent in range. Often Eco mode will provide about an additional ten percent in range when driving around town. Eco mode doesn’t really add any range when driving on the freeway. This car is still suitable for all of our typical around-town usage, but may not be satisfactory for others. I have written another article (here) that will discuss some of the factors that can impact battery degradation.

When new, the EPA combined range was 84 miles adjusting for their change in measurement parameters that they changed in 2013. As the battery degrades (loses bars) the range diminishes. These images show a full charge (all twelve blue and white bars illuminated) with a range of 57 in Drive mode. This is the mode that EPA measures the driving range. When your cell phone’s battery starts to age, your talk time decreases between charges. When it’s your car, your driving range decreases. That’s what battery degradation is.

Nissan has a battery capacity warranty that will provide a new battery for this LEAF under certain conditions. The capacity warranty says that when four bars are lost within 60 months or 60,000 miles of the original sale, they will restore the car to at least nine bars on these 24 kWh battery cars. On the newer 30 kWh battery cars, the capacity warranty is 96 months or 100,000 miles due to improved chemistry. In practice, Nissan has been replacing the entire battery pack restoring the range to new, which in this case the EPA says would be about 84 miles. Also, the chemistry of the replacement pack is improved over the original so it should degrade at a slower rate than the original and possibly provide slightly improved range over the original. Should you be outside the capacity warranty, the price to replace a battery is currently a little over $6,000. While that is a lot of money, one only need ask themselves this question: Do I want to spend $25,000 to $35,000 in a new car, or would it be better to spend $6,000 on my LEAF and drive it another five years?

Writing this article has created a couple of other areas of interest for me, so I’ll be writing about an easy way to optimize your range as your vehicle ages soon. I’ll also be writing about the possibility of getting a used LEAF or other electric car as your second family vehicle.

{ 8 comments… read them below or add one }

Nick Riley May 30, 2017 at 1:47 am

Good article Ernie. As a comparison, I have a 2013 Leaf but it is one of the 2nd generation ones. I have over 44000 miles used over three and a half years and I still have 12 bars (around 92% of original range according to Leaf Spy). I also live in the UK where our ‘less hot’ climate means that less stress is put on the battery chemistry.

Reply

Ernie Hernandez May 30, 2017 at 9:39 am

Nick – Welcome to Living LEAF. And thanks for the insight on the 2nd gen battery reliability. It’s important that readers realize that improvements have already been made to reduce this as an issue.

Reply

Kiki Jewell June 2, 2017 at 6:18 pm

For the hard core geeks here, I found this lecture to be deeply fascinating: https://youtu.be/pxP0Cu00sZs

Tl;dr, bottom line is that when charging while hot, it causes parasitic side reactions to accelerate, causing rapid degradation of battery recovery. Ironically, fast charging caused less damage than slower charging – because you’re spending less time charging. My supposition is that this is because parasitic side reactions happen while the lithium ion is traveling between the cathode and anode. In other words, this doesn’t happen while the car is idle.

This is a particular issue with the Leaf due both to chemistry choice (lithium magnesium oxide) and lack of active liquid cooling. There was a class action suit about this.

In any case, you should watch the whole video, if this topic interests you. (Note: I heard that Jeff Dahn now works at Tesla.)

Reply

Ernie Hernandez June 3, 2017 at 4:06 pm

Kiki – Welcome to Living LEAF. The video, for those who haven’t watched it, is a little over an hour long with questions at the end, but is very informative. It does appear that the Tesla battery chemistry seems to be of a longer lasting design than that found in the LEAF. I don’t believe professor Dahn has moved to Tesla, but his university has signed a partnership agreement to work with Tesla on battery development.

Reply

Lauren August 9, 2017 at 2:10 pm

I am in the market for a new car (by this weekend) due to unforeseen circumstance.

My ideal vehicle is a used 2012 LEAF SL. I am interested in purchasing this vehicle from a dealership with a 90 day warranty.

Is there anything that would be a red flag to not purchase this particular vehicle? I have been reading your articles and have learned a lot of information regarding battery deterioration and battery warranty.

Reply

Ernie Hernandez August 9, 2017 at 7:18 pm

Hi Lauren – Welcome to Living LEAF. Your choice of a 2012 LEAF SL is a good one for many reasons. It is well-equipped, yet offers a good value. By now you know to check and see how many bars it has left. Look at the car during daylight hours, and look down the side of the car to make sure that the panels are straight. Body repair work from a previous accident may show up as mis-colored paint panels or waviness in the door or fenders. A Carfax report will show original sale date, maintenance records, and how many previous owners there have been. Best of luck!

Reply

Mark Hagel September 11, 2017 at 8:22 am

I purchase a 2013 Certified Pre Owned Leaf SL with 30,000 miles in Dec 2016. I knew that battery capacity was at 9 bars when I purchased the car. I was betting on the car losing the fourth bar before the 5 years 60,000 miles were up. Last week the car finally lost its fourth bar so tomorrow it goes in to the dealer.

Reply

Ernie Hernandez September 11, 2017 at 11:19 am

Mark – Welcome to Living LEAF. I too am now the owner of a LEAF that has lost four bars. I’ve yet to take it in for the inspection – probably one day this week.

Reply

Leave a Comment

Previous post:

Next post: