All electric cars are different and the distance you can travel on one full charge varies. Generally, most cars can travel over 100 miles on one full charge, however some high-end electric cars such as Tesla's can travel over 300 miles.
There are other factors which can affect the range of an electric vehicle when driving. For example, weather conditions, battery performance and whether you're using the air-con or heating.
If you travel a lot of miles and are unsure whether an electric car is right for you why not consider leasing a hybrid car instead. Hybrid cars combine the low-emission and environmentally friendly aspects of an electric car with the convenience of a petrol/diesel car. Hybrid cars aren't quite as environmentally friendly as electric cars but if you run out of charge you can continue your journey using the combustion engine.