There's quite a difference between charging a 1Wh phone battery and a 24kWh car battery. A school might not mind if I have a quick drink from a water fountain, but they probably wouldn't want me to drag a hose over there and use it to fill my bath. From the article:
According to
Ofgem, the average home in the UK uses around 3,300 kWh of electricity per year. An electric car which gets charged a couple of times a week is equivalent to an entire household's electricity use. Far from indicating prosecuting such a crime is silly on the face of it, the comparison of electric cars to homes seems entirely appropriate.
The article says it was an "external power outlet", which suggests to me he just plugged into a normal socket rather than there being a dedicated charging station for cars.
Several people have said that last part, but as far as I can tell there doesn't seem to have been any punishment at all yet. The man was arrested. There is no mention of him having been tried and sentenced. Spending a short time in jail while the police deal with your arrest is not particularly unusual, and has nothing to do with your eventual punishment or even whether you're guilty or not. That does unfortunately mean that entirely innocent people can spend time in jail while things are being processed, but it's nothing to do with punishing them.
More importantly,
legal precedents. I completely agree with the general sentiment that stealing such a small amount doesn't exactly warrant the death penalty. But small amounts add up, and electric cars don't actually use particularly small amounts in the first place. Sure, the school could have afforded a few cents that this guy used. But if they say he's free to use their electricity, what happens when a bunch more people want to do so as well? They certainly can't afford to let everyone charge their cars, so a line needs to be drawn somewhere.
Shoplifting seems a reasonable analogy.
Charging a phone is equivalent to smelling food while walking around a shop. Technically you're taking away part of the food, but it's such an unmeasurably small amount that no-one has any reason to care. But if I take so much as a single grape, I am stealing and will likely be prosecuted for doing so. Sure, it's only a small crime that doesn't call for a huge penalty, but it's still noticeable and it's the principle that matters. That one grape isn't going to bankrupt the store, but if you let everyone take one pretty soon you'll end up with no food left to sell.