DC surge protectors (SPDs) are key devices for protecting DC systems from lightning and transient overvoltages. They utilize components such as MOVs and TVSs. They offer high resistance in normal operation, but conduct in nanoseconds to dissipate excess energy and clamp voltage when exposed to surges such as lightning strikes or switching operations. They must match the system voltage, selecting suitable Imax and Uc ratings. They should be connected directly to the nearest short-circuit ground and used in conjunction with circuit breakers. They are suitable for use in photovoltaic, charging station, and data center applications.