Gimme back my Leaf!

Today, 8 January, was as cold as you would expect Glasgow to be this time of year. However, for this winter, it was uncharacteristically cold as we've had exceptionally mild temperatures thus far. Consequently, there have not been too many days when I can get to grips with charging the Leaf in cold weather. Today was one that tested the system.

The Leaf had been left plugged in for a couple of days as I hadn't got around to unplugging it. During that time, there had been some rain. When I looked out this morning, there was a picturesque coating of frost on everything. It wasn't deeply cold but skies had evidently cleared and the temperature had headed below freezing point.

By lunchtime, we had decided to go out for food so it was suggested I get the car warmed up. I prodded the app on my phone to switch on the climate control from within the house. Within 20 seconds the blue light in the car was flashing to show it was heating up. Within 4 minutes, the frost on the windscreen had liquefied and a dry patch was forming. By 10 minutes, the warm air on the inside had heated the windows sufficiently to defrost all of them.

We headed out of the house and locked up. "Hop in quick," I suggested to my wife, wanting to keep as much of the warm air in the car as I could. Meanwhile I went to the car's nose to remove the charging cable. The normal sequence is to press a button on the top which is one end of a plastic lever, the other end of which is a latch to hold the plug firmly in its socket. I then pull it out. The button also tells the car that it is being unplugged which stops any charging that might be happening. If the remotely-switched heating is on, the button also causes it to stop.

I pressed the button and immediately felt a resistance to its movement. The plug would not unlatch and repeated attempts were to no avail. I figured the rain over the last couple of days had got into the plastic lever mechanism and had iced up. The Leaf was going nowhere.

We made our journey in my wife's car and returned an hour later. Being the middle of the afternoon, most of the frost on the cars had melted so I had another go. I felt a slight crunchiness as the button depressed. I had crushed what remained of the ice inside the lever mechanism and I was rewarded with the plug coming cleanly away in my hand. I wouldn't have to phone the Nissan breakdown service after all.

My lesson is to try and avoid leaving the car plugged in for long periods where rain might ingress the plug's latch mechanism and then ice up. On the other hand, I can easily imagine a situation where the car gets plugged in overnight, then there is a rain shower followed by clear skies before dawn which freeze everything solid. Were I able to park the car under a overhang or in a car port, this wouldn't be a problem as it would be kept dry. But I can't and so the plug and socket are exposed to the elements.

Strictly speaking, the flaw is in the design of the plug and is nothing to do with the car itself. It's just something I'll have to be aware of.

The cost of power

A few days ago, a friend asked me if I knew how much I had spent on electricity to run the car. Interesting question and quite hard to answer. The Nissan website tells me how many units of electricity I have used each day and I cold add that up. Also, I believe that Chargemaster, who installed my outdoors charger, could tell me how many units have passed through that unit, but I have yet to subscribe to that service. The problem with either of these is that while there is significant sunshine, a decent fraction of the car's power comes from my solar panels and thus, I don't pay for that. But there's nothing to tell me what fraction came from the panels.

I do, however, have an interesting graph. Because I keep a note of my retail electricity meter, I can compare last year's purchase with this year's. Here's a graph that shows the cumulative difference between the two.

For the first 40-odd days, we were purchasing no more electricity than we did last year. Then for the next 20 days, we were actually purchasing substantially less electricity than last year, which I conclude was due to the very sunny October we had. The little upward tick around day 77 to 79 was when I was getting charge from a Glasgow car park every day and around that time, I made a trip to England with a diesel car loaned to me by Nissan. What this shows is that for the first 80 days of ownership, despite running the car, we bought no more electricity than we had a year ago.

As we plunged into a very dark, wet November and December, the situation changed and the graph takes a nosedive. What's then interesting to see is that for the past 20 days, it has levelled out again.

As of today, over the time I've had the car, we have bought 279 units more than we had last year. That's all the graph says. I can't define exactly what part of that was caused by the car. Ignoring the daily standing charge (which I would have had to spend anyway), my cost per kilowatt-hour is 11.76 pence. Having had the car for nearly 5 months and done over 2,500 miles, I've had to buy £32.81 more electricity this year than I did last year. If I had made more of an effort to get power at public chargers (most of which are free), it would have been even better. Fascinating!