The biggest feature of solar LED street lights is that they are usually powered by batteries, and batteries have some characteristics that need to be considered:

3.1 There are only a few specified voltages for batteries, with 12V being the most commonly used as it is the standard voltage for automotive batteries. 24V requires two in series. 36V is even rarer. For this reason, it is often necessary to use a boost type constant current drive module in solar LED street lights. This affects the efficiency of the constant current module.

3.2 Another issue that needs to be considered in solar street lights is the change in input voltage

For the output power and efficiency of a constant current source, to achieve the highest efficiency, it is necessary to maintain the ratio of input and output voltage as close to 1 as possible. But if the input voltage is unstable. So it is difficult to maintain the highest efficiency * * * state. Solar LED street light systems typically use batteries as energy storage units. The voltage of the battery will change significantly when it is just fully charged and almost discharged. Usually, this change exceeds 30% or more. 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. It is completely possible to maintain a constant output current within such a large range of changes. But there is also a cost to this, which is that it cannot work in a * * * state. The so-called * * * state refers to the state with the highest efficiency. Or the state with the highest output power.

For constant current modules, whether they are boost or buck, the efficiency is 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 accordingly. In order to ensure that it can work in the worst-case scenario, it cannot work in * * * * state!