No rover does autorecharge. And it's the worst with the transports, especially if you have plenty of them it is a small bit of micro you could ignore... but can't as depending on how you build you risk having them empty, not noticing and a vital trade route killing of something important (or every human being at worst case).
They should rush to a cable as long as one is in range if they know they can't make the journey (this wouldn't work for when you use them to mine resources and carry them though) when on a transport route.