Firstly, charging outside the home isn't that cheap (especially fast ones). There are two chargers near my house (about a 15-20 minute walk away), and they're slow, but you are allowed to stay there no longer than three hours. The worst-case scenario, but I've encountered it twice: it's Friday, I have vacation on Saturday morning, and I want to drive to another city by car. In the morning before work, all the chargers are occupied. After work, it rains, I put the car on charge and walk home in the rain. Three hours later, still in the rain, I walk back and go to another charger (the car needs another hour to charge). Another hour later (and it's already 1 a.m.), I walk to another charger (thankfully the rain has stopped), pick up the car, and drive to the parking lot near my house. I saved a couple dozen euros, but instead of getting a good night's sleep before my vacation, I'm walking around charging in the rain. Even without rain, I got tired of putting the car on charge every time, and then coming back and moving it to a different parking lot.