I use a Dynamite Passport 100w charger. It runs on AC and has a slightly better charge rate on DC but that requires a separate power supply.
It will do 2 batteries at once and has modes for quick, balance and storage charging. There are faster and slower chargers than mine but I am happy with...
Batteries come in many sizes now. It is best to look at chargers after you have narrowed down what kind of RC you want to run. That will determine what size of batteries and charger you need.
A charger may charge a small battery quickly but take all day for a larger one. It eventually come down...