Electric vehicle batteries just don't last, do they?

There is quite a famous (infamous?) episode of Top Gear (Series 17, Episode 6) where Mssrs. Clarkson and May take a test drive in a Nissan LEAF and a Peugeot iON. Apart from sensationalising range limitations (which I believe was a stunt involving deliberately running down the battery levels prior to starting to film), the episode makes certain claims about how long batteries will last and how much they cost to replace.

One claim is that you can ruin the battery pack in 3 years if you fast charge all the time, and a related claim is that if you slow-charge then the battery pack will last "maximum 10 years, possibly 5" with a replacement cost of £7,000.

At first glance this seems terrible. Why would you buy a car where you had to spend £7,000 every 5/6 years? It would be the equivalent of buying an ICE car in the knowledge that you had to replace the engine every 5/6 years (or 3 years if you go hard on it). You simply wouldn't do that.

However, the reality has been shown to be very different to the claims made in that episode.

It is generally accepted that Nissan LEAF batteries degrade at about 3 to 4% per year, with degradation more linked to age than mileage. There are variables that can affect this, but that's the accepted degradation rate. So, I decided to put my own car to the test.

My car turns 4 years old this month (January 2019), so I'd expect somewhere between 12 to 16% battery degradation in that time. To test this, I connect an OBD2 dongle into the computer in my car, and using an app (called LeafSpy Pro) on my phone, I am able to view a lot of data about the car that is normally hidden.

The image below shows the battery cell report:

The blanked out part is the VIN, and the value highlighted in red is the State Of Health (SOH) of the battery pack. The "odo" reading is the mileage of the car, and the QC refers to number of Quick Charges, while L1/L2 refers to the number of slow charges.

As you can see, after 4 years and 72,242 kilometers, the battery pack still has 87.74% of its original capacity. This is at the lower end of what would be considered normal degradation, so no complaints there. I can easily get 100km at worst from that capacity, so all things being equal in another 4 years the car will have about 75% battery capacity and a range of about 90km at worst. 

The reality is that I will not have to replace the battery any time soon, if ever. This is a long way from the claims made by Clarkson (remember: as little as 3 years if you fast charge, 5 if you slow charge before requiring a replacement costing £7,000). It just goes to prove that some anti- EV claims made in mainstream media really need to be taken with a sack of salt.

For anyone in the Galway are who has a Nissan LEAF, I'd be happy to meet up with you and test the battery health in your car for you using the OBD2 dongle that I have. Just comment below, or drop me a line.