How To Verify The Technical Parameters Of Solar Street Light?

•Solar Panel watt is decided by 2 factors: ①Size and ②Efficiency.

•For mono crystalline solar panel, highest cell efficiency in the industry is 24%. After made into complete sheet solar panel and calculating by the dimension of all in one solar street light, the maximum efficiency is 18.2%. So imagine(actually not) all suppliers using highest efficiency solar panel with 18% efficiency. You could calculate the actual solar panel watt by formula as below:

Length(mm)*Width(mm)/1000*18.2%=Watt

•Take our 140W solar street light with 180W panel for example. The dimension is 1855*535mm. So the actual Watt=1855*535/1000*18.2%=180.6W. There might be small deviation. Our actual watt is 180W.

•With this formula you could calculate all the solar panel watt of other companies. Many other companies' actual power is only 60%-70% of their ratings.

•Mostly used Battery Type: ①MnNico Ternary Lithium Battery, ②LiFe PO4 Lithium Battery.
Main difference is resistant working temperature and cycles(Lifetime). MnNico Ternary lithium battery resistant temperature is -20°to 40°, cycles is 1500 times, LiFe PO4 lithium battery is maximum 60°, cycles is 3000 times. So in areas with high temperature like Middle East, Africa and South East Asia, we must use LiFe PO4 Lithium battery.
•IMPORATNT: Many companies using 2nd hand cell which is used from electric cars. These kind battery are Grade B, lifetime is only around 3 years. What we used is Grade A Dynamic lithium battery which is exactly same cells as the electric car.
•Capacity of battery. Take 32700 model for example, this number means the cell diameter is 32mm, Height is 70mm. Each cell capacity is 3.2v 6Ah.
Take our 140W solar street light with battery 25.6V 48Ah for example, it is composed with 8 series(25.6V/3.2V=8) and 8 Parallels(48Ah/6Ah=8), totally 8*8=64 pcs cells. Each cell weight is 150g, so only the net weight of cells is 150*96=14,440g=14.4kg. Plus battery box and other materials, the weight is over 17kg.
•Actual Battery Capacity and battery grade are frequently cheated by many suppliers.

3.2V System means all the battery cells are connected by parallel. 12.8V means 4 series connection, and 25.6V means 8 series connection.
For 3.2v system, if any cell defects, other cells still work and not influence the complete performance much. For 12.8v/25.6v system, if any cell defects, then the complete series defects and the complete battery capacity would be much reduced.

Seems the 3.2v system is better than 12.8v system? but why we still using 12.8v or 25.6v system? Because to reach same output power, it would need smaller current under bigger voltage system. Big current would cause big load pressure for the complete system, at the same time more self loss during transmit.

Take 140W For example, to reach 140W output, if using 25.6V system, the current would be 140/12.8=5.47A, but if for 3.2v system, the current would be 140/3.2=43.75A. It would be big impact for the system, causing problem of over heat, electricity loss, easy to burn...

Then why some companies still prefer to use 3.2v system? Because if the cells connected by series, then all the batteries in this group should be in consistent voltage and resistance, that would have higher demand for the original cell quality. But for 3.2v parallel system, no need the consistence for the cells. So 3.2v system means the original cell quality is not good.

Conclusion: 3.2v system means the cells quality bad, and probably it is 2nd hand battery.

Battery Module Design

(1)Replacement Convenience
Suntisolar Battery is packed by separate battery box, which could be easily replaced after battery lifetime ends, which could be done easily with the light on pole. The old design must be taken off from pole and open the complete light body for battery replacement

(2)IP Grade
With single battery box design, the actual IP Grade reach IP66. Comparing the old design IP grade is only IP 54 actually, though most marking IP65.

•LED Quality is mainly judged by 2 parameters: ①Lumen Efficiency ②Lifetime
•Lumen efficiency is mainly influenced by LED Chip and LED Encapsulation mode(3030/5050). 3030 Chip efficiency is 210lm/W, 5050 efficiency is 240lm/w maximum. We are using 5050 LED.
•Lifetime is influenced by 3 factors: ①LED Chip, ②LED Encapsulation Mode, and ③Heat Radiation. LED Chip and LED Encapsulation are not produced by ourselves but are purchased from leading industry companies to make sure reliable quality. LED Heat radiation is designed by ourselves with large and solid die casting aluminum to make sure lumen maintenance reaching 80% after 50,000 hours and 60% after 100,000 hours.

•There are 2 kinds materials of bracket mostly used: ①Die Casting Aluminum ②Welding Aluminum.
•Die casting aluminum is much stronger than welding aluminum. Especially for high power solar street light, the weight is heavy. Die casting aluminum has much better safety guarantee. What's more, our unique design of double gear guarantee the light never fall off no matter how big the wind is. Other is only single gear which is difficult to hold the weight under big wind.

•Aluminum house strength
Aluminum shape is easy to deform especially under high temperature and weight. What we used is big sectional area aluminum to make sure the strength of the complete solar street light.