Deep Cycle

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A deep-cycle battery is a lead-acid battery designed to be regularly deeply discharged using most of its capacity.

Typically discharges between 45% and 75% of its capacity, depending on the application and the construction of the battery.

Although these batteries can be cycled down to 20% charge, the best lifespan vs cost method is to keep the average cycle at about 45% discharge.

There is an indirect correlation between the depth of discharge of the battery, and the number of charge and discharge cycles it can perform.