DC-DC Converter - An electronic circuit which takes a DC input voltage and converts it to a different, desired DC output voltage.
Deep cycle battery - A battery designed to be discharged to below 80% Depth of Discharge. Used in marine, traction and EV applications.
Deep discharge - Discharge of at least 80% of the rated capacity of a battery.
Discharge - The change from chemical energy within the cell into electrical energy to operate a external circuit.
Discharge capacity - The amount of energy taken from the battery when discharged at the rated current and ambient temperature until the discharge end voltage is reached. Generally expressed in units of Watt hours (or Ampere hours for batteries with the same voltage).
Discharge rate - The current delivered by the cell during discharging. Expressed in Amperes or multiples of the C rate.
Discharge voltage - The voltage between the terminals of a cell or battery under load, during discharge.
Dry Cell - A Leclanché cell with a gel electrolyte.
Duty Cycle - The load current or power a battery is expected to supply for specified time periods.