2. Lead-acid battery depth of discharge Lead-acid batteries, commonly used in automotive applications, can tolerate deeper discharges, typically up to 50% DoD, without significant impact on their longevity.
Never fully discharge a lead-acid deep cycle battery! As we’ve said, the deeper you discharge the battery, the more its total cycle life reduces. Most deep cycle batteries can handle only up to 50% depth of discharge, although some are built to handle up to 80% discharge. Never fully discharge a lead-acid deep cycle battery!
The recommended battery DoD varies by the type of battery and manufacturer. Let’s cover the average depth of discharge of some common batteries. What Is the Depth of Discharge of a Lead-Acid Battery? The recommended depth of discharge for lead-acid batteries is 50%.
“Lead acid batteries should be discharged only by 50% to increase its life” – is an oft used phrase. This means that we should cycle them in the 100% to 50% window as shown below in the Typical state of charge window parameter. So it follows that the usable capacity of a lead acid battery is only 50% of the rated capacity.
The following graph shows the evolution of battery function as number of cycles and depth of discharge for a shallow-cycle lead acid battery. A deep-cycle lead acid battery should be able to maintain a cycle life of more than 1,000 even at DOD over 50%.
Most deep cycle batteries can handle only up to 50% depth of discharge, although some are built to handle up to 80% discharge. Never fully discharge a lead-acid deep cycle battery! If you frequently recharge your battery in a complete cycle, you can get just over 220 complete cycles if you drain it 80% each day.