The characteristics of Lithium-ion batteries that are commonly used include the minimum allowable voltage of 2.75V, maximum voltage of 4.2V, resistance in the battery when measuring in AC. However, this creates a new problem in the length of time it takes to charge the battery. Therefore, all manufacturers compete in offering fast charging solutions for faster battery charging.

A good charger must be able to charge the battery quickly without damaging the battery. To keep the battery in good condition, maintenance is needed, including choosing a quality charger because the lifespan of a rechargeable battery is also affected by its charging. With the Fast Charger with a larger power capacity, it can indeed be filled faster than a regular charger. So that the battery does not experience overcharging, there must be a mechanism to monitor and control the work of the charger. Some of the methods that are often used include constant voltage, constant current, multistage methods, monitoring the acceleration of temperature rise, monitoring the acceleration of increasing battery pressure and negative delta voltage.