Test: 70 Miles with Heating On

The objective of this test is simple… can the Nissan Leaf do a 70 mile journey with the heater on all the time?

This was suggested as a journey that might be done regularly by a member of the Nissan Leaf Owners Club and what a better way to have a bit of fun learning about my Leaf than to test out this question.

So, I started with a full charge of 100 miles on the range. The task then was to get from Saltash to newton Abbot, along the A38, at a steady 65 mph but simulating a cold winters day. In a way this is not a fair test because the temperature outside this afternoon was 15 degs C so to simulate this scenario I had to up the heat to maximum and just leave it on the the trip. Yes, it got hot, very hot! So I can certainly say that the heater works and I suspect that it will be more than adequate through the winter… but what did it do to the range?

Just for clarity on test conditions… almost all 70 miles are dual carriageway with the 70 mph limit but not motorway. Traffic was not heavy but heavy enough to require coming out of cruise now and then. Almost all the trip was in ECO mode and on cruise set to 60 mph. Very occasionally I came out of cruise to either speed up to overtake the odd HGV or slow down to merge with traffic at junctions etc.

Setting out it seemed that I was never going to make it when the range shot down to about 80 within a mile or so but soon it steadied and was pretty steady for the rest of the trip. I started to realise that the range gauge is in fact 2 gauges. The bars act just like a fuel gauge. Going down as power is used. This is a great way to see what the current state of charge is… if half of the bars are lit then you have 50% charge. The numbers is the cars best guess at the range you will get at that state of charge given how the car is being driven, hills, etc. This best guess wanders up and down as your driving style changes and as you select ECO mode or climate control etc. It is very easy to get fixated on the range estimate but it is the state of charge, i.e. the bars, that tell you how much power you have remaining. The two need to be used together to allow you to judge how far you are likely to go.

At about 5 miles away from home the bars were down to the two bottom bars and in the red with 15 miles on the range estimate. At this point I was starting to get worried and the words “range anxiety” started to be played over in my mind. This was a test and I didn’t think it sensible to push the envelope so I terminated the heat test at that point and turned the climate control off completely. I also reduced speed to 40 mph max for the remaining 5 miles with the very last 2 miles at 30 mph once off the A38.

At about 1 mile from home the “Battery Low” warning came up with some yellow warning triangles and the horn beeps once. The bars were now down to the last bar and with 10 miles on the range estimate. I was pretty sure I would get home but I have to admit to being worried. I arrived back home with 10 miles on the estimate and one bar on. To be honest, I do not want to run that tight again!

What conclusions can we draw from this test?

Well, quite a few if I read it correctly.

Firstly, in answer to the original question… yes, the car will do a trip of 65 miles with the heating on permanently but is this realistic? Not really in my opinion. In reality the climate control would be set at a more reasonable value of say, 20 degs. The climate control would have almost certainly settled down to just maintain the temperature and so I would expect a lower load from the climate control. The climate control was using between 1.5 and 2 kW for the entire trip and that is probably never going to happen especially if the car is pre-heated/cooled whilst still plugged in.

Secondly, I can see that there is warning of impending flatness, giving time to take appropriate action to find a charge point or slow down and reduce your power use. Mind you, I think it would be foolish to leave it to that stage before taking action. I will consider taking some action to get me somewhere I can charge when I get to 3 or 4 bars thereby giving me a chance to go a few miles to find save haven.

Thirdly, the heater and air con work very effectively and don’t affect the range estimation by more than about 5 miles.

Finally, this has shown me that Nissan may market the Leaf at 100 mile range but we must all approach range with caution. It is a moving target and until we have a lot more experience it is clear that to assume we can actually get 100 miles would be foolish. I am going to use 75 miles as the maximum trip distance I shall plan for for quite a while yet.

Great fun drive! More tests to come.

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