Our Nissan Leaf’s Traction Battery Capacity

By Paul Gipe

We have a 2015 Nissan Leaf S, a mass-market Electric Vehicle (EV) with a 24 kWh traction battery that gives the car an official EPA range of 84 miles.

Note: See Our Nissan Leaf’s Traction Battery Capacity April 2016 Update for current stats.

An EV runs on electricity not gasoline. To maximize the use of the Leaf, we need to know how much electricity we can store in the “tank,” that is, the traction battery. This isn’t as straightforward as it sounds.

Though the Leaf has a 24 kWh battery, not all of that can be used to drive the car. When new, other 2015 Leaf drivers have found that a fully-charged battery had 22.6 kWh or 292 Gids–a unit of energy unique to the Nissan Leaf–of usable capacity. It is this usable capacity that determines how far we can drive.

However, anyone who has a cell phone knows that batteries lose their capacity over time and with use. EV traction batteries are no different.

How do we find out how much electricity we can store in the traction battery? We need to take a metaphorical peak under the hood, or more correctly, under the car where Nissan places the Leaf’s traction battery. Leaf Spy, a smart phone app, talks to the computer in Nissan’s Leaf and displays the data it finds there—data essential to getting the most out of driving a Leaf. It’s a powerful tool every geek with a Leaf should have.

What can Leaf Spy do? It can tell you the air pressure in your tires. It can unlock your doors—and much more. It can also tell you exactly how much electricity is left in the traction battery and that’s Leaf Spy’s raison d’être.

I began using Leaf Spy in August at 6,500 miles. At that time in late summer our Leaf could store 287 Gids (22.2) kWh. (There is a direct relationship between Gids and kWh.)

Leaf Spy was also reporting that the state-of-health (SOH) of the traction battery was 98%.

With the onset of fall, however, Gids and kWh began to steadily fall away. By early 2015, traction battery capacity had fallen to 258 Gids or 20 kWh with a 88% SOH. That is, we’d lost 2 kWh or about 10% of capacity at 8,300 miles.

There’s a long ongoing discussion on mynissanleaf.com about the Leaf’s battery degradation and about how frequent quick charges appear to halt or reverse the decline on the 2015 model-year battery.

We’ve seen the same bump in capacity at the end of a 500 mile trip and 8 or 9 quick charges.

We don’t baby the car. We just drive it. We charge to 100% on a level 2 (L2) EVSE at home. When we’re on a trip where we may have access to a DC quick charge (DCQC) station we sometimes charge to 90% or more. After charging a few times since we returned, it appears the SOH and Gids are drifting down again.

Here’s what we have to date at 8,900 miles. I’ll update this chart once warm weather returns.