A charger works by connecting a constant DC power source to the battery being charged. The Charger doesn't alter its output based on time or the charge on the battery. A battery charger is a device used to put energy into a cell or (rechargeable) battery by forcing an electric current through it. The charge current depends upon the technology and capacity of the battery being charged. For example, the current that should be applied to recharge a car battery will be very different to the current for a mobile phone battery. We at Philco Dicor manufacture the best of these devices using the latest techniques and the with our best resources.