The features of a cordless power tool battery charger are mostly dictated by the type of battery it is designed to charge (see What are the different types of cordless power tool battery charger?), although there are a few additional features that can be available on any charger type.
Power lead storage
Power leads are usually permanently attached to the charger and can be awkward when storing. Some chargers are designed so that the lead can be coiled around the casing neatly.
USB ports
Some chargers have USB ports as well as battery ports. This means that you can charge small devices like phones and music players using the power coming through the charger from the mains.
