Depth of Discharge (DoD) refers to the percentage of a battery's total capacity that has already been used (discharged). DoD and SoC always add up to 100%: DoD (%) = 100% −. Energy storage systems (ESS) are revolutionizing how industries manage power, and the charge and discharge depth of batteries plays a pivotal role in their efficiency. Assuming the battery is charged for free via solar PV and offsets peak grid import, the system pays for itself in roughly 9. Calculation Example: This calculator estimates. Greater than or less than the 20-hr rate? Significantly greater than average load? So, what is ?.