This chart shows the relationship between the amount of discharge and the number of times that a deep-cycle battery can be recycled. If the battery routinely uses only the top 25 percent of its capacity, it can be recharged around 2,200 times. Drawing the battery down to 50 percent of its power cuts the life of the battery in half. This explains two things. First, do not allow the battery to discharge any deeper than necessary if you want long battery life. Second, abusing the battery by not keeping it fully charged cuts battery life, and thats expensive.