An accumulator for hydraulically actuating subsea equipment includes a hydraulic fluid chamber and a gas chamber. The hydraulic fluid chamber is in fluid communication with the subsea equipment and comprises a hydraulic piston slidably received, at least partially, within the hydraulic chamber. The gas chamber comprises a charge piston slidably received within the gas chamber, the charge piston dividing the gas chamber into a first portion and a second portion. The first portion of the gas chamber is configured to receive ambient hydrostatic pressure therein, and the second portion of the gas chamber is configured to receive precharge gas therein.