Answer: Construction / Parts of a Lead Acid battery: A Lead Acid cell is constructed by immersing the two plates of lead plated with Lead Peroxide and Sponge Lead into the electrolyte Dilute Sulfuric Acid of specific gravity of about 1.21. The Lead Peroxide and Sponge Lead has very little mechanical strength.
Step-by-step explanation:
Lead-Acid Battery Construction The lead-acid battery is the most commonly used type of storage battery and is well-known for its application in automobiles. The battery is made up of several cells, each of which consists of lead plates immersed in an electrolyte of dilute sulfuric acid. The voltage per cell is typically 2 V to 2.2 V.
Lead-Acid Battery Working
When the lead-acid cell is charged, the lead oxide on the positive plates changes to lead peroxide, and that on the negative plates becomes a spongy or porous lead. In this condition, the positive plates are brown in color, and the negative plates are gray.
Lead-Acid Battery Discharging
When the battery is discharging (i.e., supplying a current), atoms from the spongy lead on the negative plates combine with sulfate molecules to form lead sulfate and hydrogen. As always, electrons are left behind on the negative plates so that they maintain a negative potential. The hydrogen released in the electrolyte combines with the lead peroxide on the positive plate, removing electrons from the plate to keep a positive potential. The combination of lead peroxide and hydrogen at the positive electrode produces water and lead sulfate. The water dilutes the electrolyte, making it a weaker solution, and the lead sulfate that is produced at both positive and negative plates tends to fill the pores of the active material. Both these effects (dilution of the electrolyte and formation of lead sulfate) render each cell less efficient and eventually cause the battery output voltage to fall.
Lead-Acid Battery Recharging
When the battery is recharged, a current (conventional direction) is made to flow into the positive electrode of each cell. This current causes the lead sulfate at the negative electrode to recombine with hydrogen ions, thus re-forming sulfuric acid in the electrolyte and Spongy lead on the negative plates. Also, the lead sulfate on the positive electrodes recombines with water to regenerate lead peroxide on the positive plates and sulfuric acid in the electrolyte. The final result of charging the cell is that the electrodes are re-formed and the electrolyte is returned to its original strength. With proper care a lead—acid battery is capable of sustaining a great many cycles of charge and discharge, giving satisfactory service for several years.
Care of Lead-Acid Batteries
The level of the electrolyte in each cell should be checked regularly, and distilled water added as necessary to keep the top of the plates covered by about 1 cm of liquid.
Battery terminals should be kept clean and lightly coated with petroleum jelly to avoid corrosion.
In cold weather, batteries should always be maintained in a nearly fully charged condition to avoid freezing.
Lead-acid batteries should never be allowed to remain for a long period in a discharged state because lead sulfate could harden and permanently clog the pores of the electrodes.
Before storing it for a long time the battery should be completely charged, then the electrolyte should be drained so that the battery is stored dry.