A solar charger does not necessarily have an integrated battery so external battery is attached to store energy at the time when no other load is connected. Typically, any type of battery can be charged using solar charger. But deep cycle batteries are best to use with solar charger. Battery with higher number of charge discharge cycles is preferable for solar chargers as well. Moreover, battery voltage must be equal to solar charger's DC output port voltage or little less. Capacity of charger and battery should also be compatible so battery gets charged fully within stipulated time frame.