2011 Nissan Leaf Battery Lifespan

In 2011, I took a leap of faith. After spending more than a year on the waiting list, I bought a brand new, 100% electric car. This was the first new car that I had ever bought.

I considered leasing it so I could walk away if the technology turned out to be less than I hoped. However, I don't like leases and after driving electric for the 4 previous years, I knew EVs had great potential, so I paid cash on the barrel-head and became the owner of a new electric car on May 18th 2011.

Two and a half years later, I still love the car. It still has all 12 bars of capacity and the range has not diminished. I plan to keep the car for 10 years, so maintaining battery health is important to me. So I generally avoid quick charging and I have the car in "Long Battery Life" mode so that it only charges up to 80%.

Even with these precautions, batteries will degrade slowly with the passage of time. I recently started running a program called Leaf Spy that, along with a cheap ELM from Amazon, allows me to read messages from the car's CAN bus. This shows a lot of data. Among this data is the current capacity and health of the batteries.

Here is a chart of the data I have collected so far:

For purposes of the chart, I made the assumption that the car started out at 100% capacity and health. I was surprised to see how much the capacity changes with the weather and use. The spike in capacity occurred when my car received a firmware update in the later summer of 2013.

This chart will be interesting once there are multiple years worth of data, where seasonal changes and longer term trends can be seen.