Which street lamp with solar battery is better,3.7V or 12V?

   In the market,it have kinds of street lamp with solar battery products.The competition is getting fiercer.After analyzing the sales price of this market,we have founded that under the same system configuration,3.7V street lamp with solar battery is cheaper than 12V street lamp with solar battery.But which street lamp with solar battery is better,3.7V or 12V?

         Before answer this question,we need to know how it can have 3.7V solar street led lamp.Led chip voltage is around 2.8V~3.2V per pc,Lithium battery cell is 2.75~4.2V per cell.If all of them connect in parallel,it can build a 3.7V solar street led lamp system.We can find the power for 3.7V solar street led lamp system are between 10W to 30W.The supplier sell the system with these advantage:The same capacity is ultra-low-cost, and the lighting is more energy-saving. We can prove that the 12V solar panel outdoor lights system is better than the 3.7V solar panel outdoor lights system for the following reasons. Firstly, the operating voltage range of the lithium battery is: 2.75~4.2V or 2.5V~3.65V. The effective working voltage range of the LED is generally 2.8V-3.2V. Exceeding this range will affect the light efficiency and life, and the controller will enable PWM Or MPPT can regulate the current and achieve the effect of bucking. For the battery with 2.5V~3.65V operating voltage range, the brightness of the lamp bead below 2.6V is obviously darker.

      Secondly, the street lamp with solar battery system known as 30W, in fact, the actual output is generally about 20W. The output current is greater than 7A. The maximum solar energy at the charging end is 60W, and the maximum charging current is as high as 15-20A. This puts higher requirements on the safety heat dissipation of the system, and the switching loss and internal resistance loss of the controller are large. Even if the charging tube is connected in parallel, it is difficult to solve the heating problem caused by the switching loss exceeding 10A. It will burn the controller and the battery. Such a large current will have a great impact on the life of LEDs and batteries, because controller manufacturers with research and development capabilities are very cautious about low-voltage control systems. Thirdly, a large number of cells in parallel have higher requirements for the consistency of the cells, and the same is true for LEDs. A large number of cells in parallel will inevitably affect capacity and quality. In addition, the low voltage and large current self-loss are large, and the line loss is also large.