It is a container full of energy, using conversion of electrical energy into a chemical (charging process), acumulate part of that energy. A revers process is going on when you connect a vehicle (by terminals) to its battery poles, i.e. conversion of chemical energy to a electrical energy (discharge process).
It consists from one or more cells that have two type of electrodes (cathode and anode), that are immersed into a electrolyte. In charged state every cell has a negative lead electrode and positive electrode of lead dioxide, immersed in electrolyte of 33,5% sulfuric acid. In discharged state both electrodes become lead sulfate and electrolyte loose great ammount of te sulfuric acid.
Fully discharged battery – two identical lead sulfate plates. Electrons were conducted from positive plate into a cell, and then to a negative cell.
Fully charged battery – lead plate (negative) and lead dioxide plate (positive). Electrons were conducted from negative plate to a positive plate.
Overcharging with high voltage generates oxygen and hydrogen by decomposition of the water form electrolyte. Maintenance of the lead acid battery demands control of the electrolyte level and adding water if necessary.
Capacity of the battery is expressed in Ah (amper hour). Basically, product of the time of discharge with average discharge current shoul be equal to the capacity of the battery. But, capacity depends on mode of charging and discharging. Battery can not be operative without electrolyte, lead acid cell sholud not be discharged under 1,8 V per cell or stays on open circuit without recharging, and should not be under strong current schock.
If you charge – discharge the battery with high current, its capacity will decline (it will have sufficient voltage for shorter period of time). Battery capacity declines at lower temperatures and thats why there are problems with battery during the winter months. Direct short circuit on terminals – battery poles can be very dangerous and cause heavy burns, fire, eye injuries and even the explosion of the battery. During the normal service life, batteryu lose water. From time to time, customer must check the level of the electrolyte (that should cover the plates about 10 mm). If necessary, one should add only water (destiled), and not acid.
During the charging, positive pole of the charger connect to the positive battery pole. During charging, on the electrode oxygen evolves, and on the other one evolves hydrogen. Mixture of theese gasses is explosive. Because of that, in the case of charging a great number of batteries, or for charging the high capacity batteries, the instalations must be according to the special regulations, with enough air in the room, and with the special electric installations.
Batteries last longer if you store them fully charged. Discharged battery in the warehouse means shorter life cycle or fully unoperable battery if it lasts for longer period of time: sulfatization becomes irreversibile. Batteries in the warehouse must be controlled and periodically charged or connected to a charger to maintain their capacity. Batteries must be stored on cold, dry place in order to maintain their characteristics because high temperatures increase self discharging process and corrosion of the battery plates.
Date of production
Because of sulfatization process, flooded batteries are selfdischarging in the warehouse.