Regulators control the current flowing to the battery and prevent the battery current from flowing to the charging source. These solar panels do not include an on-board voltage regulator, so a stand-alone regulator would be required to complete a power supply.
Typically, these solar panels are connected to a CH100, CH200, PS100, or PS200, as well as to the battery base of a CR3000 or CR5000. The PS100 and the PS200, as well as the battery base of the CR3000 and CR5000, include an internal regulator.