Traction batteries are mainly used in heavy industrial electrical applications such as: electric forklift trucks, electric tractors, large industrial cleaning machines, aerial platforms, …
A traction battery consists of several cells of 2V. When those cells are connected in series, you get higher voltages. A traction battery of 24 volts has 12 cells, a 48 volts battery has 24 cells, a 80 volts battery has 40 cells. To recharge a battery, the cell voltage has to be increased to above 2 volts by an external voltage source.
Traction batteries differ from starter batteries because they have been developed to provide a certain amount of energy for longer periods. As a result, traction batteries usually have a much higher capacity than starter batteries.
Composition of a traction battery
A traction cell is composed of positive and negative plates, there is always 1 negative plate more than the number of positive. The positive and negative plates are separated from each other by means of a micro porous separator in order to avoid mutual contact and short circuit.
The positive plate consists of a tube plate and a number of lead rods together, which are then protected as a whole by a porous material that is folded around the plate like an envelope. The space between the plates is filled with a paste of lead dioxide. The exact composition of these plates varies from manufacturer to manufacturer and is already an important part of the final quality of the cell.
The negative plate is a grid of pure lead. These plates are in a bath with electrolyte, a mixture of sulfuric acid with water.
The different technologies
Traction cells already exist in different technologies, these are: Open Lead Acid, Pure Lead, Gel and Lithium-Ion :