Our portable electronic devices like smartphones, smartwatches, laptops, torches, and power banks, etc all these things require some portable supply of energy to use these devices. The conventional AC supply available cannot be used to run such devices hence we need a portable DC. Different parameters of the battery define the characteristics of the battery, which include terminal voltage, charge storage capacity, rate of. Many parameters are required for the selection of the battery for a particular application, such as voltage rating, current rating, life cycle, charge capacity rating and so on which. This part can be categorized into two parts first is replacing the battery bank with a new one and the second is a complete installation and commissioning of the battery bank. To do. It is desired that batteries used in the solar PV system should have low self-discharge, high storage capacity, rechargeable, deep discharge capacity, and convenience for service. For such a.