Detailed explanation of the operation of the battery in the solar LED street light accessories

The battery accessories of solar LED street lights are a problem that must be paid attention to, because it is a battery. Without this battery, solar LED street lights will not be able to use the energy converted from absorption. Solar LED street lights are usually powered by batteries, and batteries have some characteristics. It needs to be considered: 　　 1. The battery has only a few specifications of voltage, 12V is the most common in use, 24V needs two in series, 36V is even rarer. For this reason, boost constant current drive modules are often used in solar LED street lights, which affects the efficiency of constant current modules; 　　2. Another issue that needs to be considered in solar LED street lights is the change of input voltage. For the output power and efficiency of the constant current source, to get the highest efficiency, it is necessary to keep the ratio of the input and output voltage as close as possible, but if the input voltage is unstable. Then it is difficult to maintain the best state of maximum efficiency.　　 Solar LED street lamp systems usually use batteries as energy storage units, and the voltage of the batteries will change greatly when they are just fully charged and almost discharged. Usually this change exceeds 30%. For example, for a 12V battery, its output voltage can vary from 14.8V to 10.8V. Of course, for constant current modules, such changes are completely tolerable. That is to say, the output current can be kept constant within such a large variation range. But this also has a price, that is, it can't work in the best condition. The so-called optimal state refers to the state with the highest efficiency or the state with the highest output power.　　 For constant current modules, whether it is a step-up or step-down type, the efficiency is the highest only when the output voltage is closest to the input voltage. Usually the output voltage is determined by the load and rarely changes. So when the input voltage changes within a range, its efficiency also changes. In order to ensure that it can work in the worst case, it can't work in the best condition! The voltage is connected recently to achieve the best utilization rate, and the voltage must be controlled within a certain range to ensure the stability of its use.