It was a typical scenario. I’ve got to be at the BA Gatwick check-in by 12.30pm. Which means I need to leave Battersea - 27 miles to the north - by 11.00am, which allows a reasonable margin for hold-ups.

The round-trip of 54 miles is also well within the capability of the Nissan Leaf’s fully-charged battery pack, so I’m going to do my first airport run in the car. Which all sounds nice and straight forward.

It was, until I got a few miles down the A23 and the traffic came to halt just beyond Ikea. I was stuck for 25 minutes in a jam that turned out to have been caused by a single lane being fenced off.

By that point - and the trip computer said I had completed just 8.4 miles in 60 minutes - I was pretty sure I would miss the plane. And British Airways have a habit of closing the desk minutes after the hour’s check-in deadline arrives.

But I was advised by the PRs running the trip to chance my arm and press on to Gatwick. So I pushed the Leaf hard along the M23 and shot into the short-term car park. Before I ran for the desk (and, though 15 minutes late, BA did actually issue me a boarding card) I noticed that the high-speed blast on the motorway had hammered the remaining range. 41 miles was, however, enough to get me home.

While on the flight, I pondered the rather odd way in which the Leaf’s trip computer calculates range. It obviously recalculates the remaining range based on the current way the car is being driven. But the range-to-empty calculation seems not to be adjusted over the length of the current journey, but over a shorter period.

So I decided to check what would happen to the range calculation on the more leisurely return journey. I left the car park with 41 miles range and then pottered off up the M23, not much exceeding 70mph. The range calculation continued to crash, forcing me to indulge in some mental arithmetic to make sure I wasn’t going to scrape home.

Once off the M-way and onto the relatively free-flowing A23, the calculated range leapt back up. Indeed, by the time I got home, I’d covered 28 miles for a reduction in range of just 11 miles from the range displayed at Gatwick. All of which is a bit confusing if you are on a journey that mixes fast motorway and slow-moving urban traffic.

But there was other scenario that I was turning over in my head as I raced to Gatwick. If I did miss the plane and had to try and find another flight to Turin, the Leaf wouldn’t have been able to deliver me to, say, Luton or Stansted, never mind get me home again.

Battery-powered travel is not ideal where sudden changes in plan are possible.