## How to calculate the battery capacity of solar power

1 Overview

In many parts of the world, the cycle of sunlight and radiant energy is 24 hours a day. The power generation of solar cells in a specific area also changes in a 24-hour period, and the law is the same as the solar radiation in that area. However, changes in the weather will affect the development of the phalanx. After several days of continuous rainy days, the power generated by the square array is very small and can only rely on battery power supply. The battery should be replenished as soon as possible after the battery is fully discharged. Designers usually use the total daily radiant energy of the sun or the annual average sunshine hours provided by the weather station as the key data for the design. Since regional data is different from year to year, the smallest data in the past ten years should be used to ensure reliability. According to the power consumption of the load, the battery should be used to supply power in a sunny place without sunlight. The total sunshine or total sunshine time provided by the weather station is important data to determine the battery capacity.
For solar cell arrays, the load must include the consumption of all electrical equipment in the system (in addition to electrical appliances, there are batteries, circuits, controllers, etc.).

The output power of the square array is related to the number of modules in series and parallel. The series is to obtain the required operating voltage, and the parallel is to obtain the required operating current. The appropriate number of modules is connected as follows. Series and parallel to form the required solar energy Battery array.

2, battery pack capacity design

The energy storage device of the solar power generation system is mainly a battery. The storage battery supporting the solar cell array generally works in a floating charge state, and the voltage changes according to the change of the power generation of the square array and the power consumption of the load. Its capacity is much greater than the power required by the load. The energy provided by the battery is also affected by the ambient temperature. In order to match the solar battery, the battery should have a long life and easy maintenance. 1. Battery selection

There are many types of batteries that can be used for solar cells. Currently, there are three widely used lead-acid maintenance-free batteries, general lead-acid batteries, and alkaline nickel-cadmium batteries. At present, lead-free batteries are mainly used in China, and their inherent "free" maintenance characteristics and low environmental pollution make them very suitable for reliable solar power generation systems, especially unmanned workstations. Generally, lead-acid batteries require frequent maintenance, which pollutes the environment, so they are mainly suitable for maintenance or low-end. Alkaline nickel-cadmium batteries have good low temperature, overcharge and overdischarge performance, but their high price makes them only suitable for special situations.