OPzS is used to refer to a flooded type of tubular-plated, lead acid, deep cycle batteries. These batteries, generally have a cell voltage of 2 volts and are connected in series to produce higher voltages.
These types of batteries are generally vented and are used in stationary applications like; solar, wind and backup energy storage. They contain a liquid electrolyte which is generally composed of diluted sulfuric acid.
OPzS stands for : O = Ortsfest (stationary) Pz = PanZerplatte (tubular plate) S = Flüssig (flooded)
OPzS batteries are often time referred to as traction batteries. A variant of these types of batteries that are valve regulated and have gel electrolyte are called OPzV. These are a maintenance free variant of OPzS.