18 Jan 2023

Four seasons with an EV

We’ve logged our longer EV journeys for a year now. We wanted to get a feel for what a realistic range is like as the days grow warmer, and cooler.

When we started out, the measure that made sense to us was: how many miles do we travel per 1% of car battery? You can picture the spreadsheet: start mileage, start charge; and then arrival mileage and charge. Subtract the numbers, do the division and … “miles travelled/percent used”.

Here’s how that looks, as mean miles/percent over the year:

Plot of the monthly mean miles per percent, showing higher values in the summer, meaning longer range

BTW: now, a year later, we’re comfortable with miles per kWh. And know how to make the car report this. But, a rough conversation from miles/percent is to multiple the numbers on the graph by 3 to get miles/kWh.

As expected, there’s a degree of relation to the change in temperature over the year. Shown here for Brighton:

Data for Brighton © WeatherSpark.com

The point of this was to know the variation of the range of our car. It helps plan longer journeys.