Solar street lights are environmentally friendly street lights that use solar energy to power them. Generally, solar energy is powered by crystalline silicon solar cells and stored in batteries. There are four commonly used types of batteries:
1. Lead acid battery
The plates of lead-acid batteries are composed of lead and lead oxides, and the electrolyte is an aqueous solution of sulfuric acid. Its main advantages are stable voltage and low price; The disadvantage is that the specific energy is low (i.e. the amount of stored electricity per kilogram of battery), so the volume is relatively large, the service life is short by about 300-500 deep cycles, and daily maintenance is frequent. Currently, solar street lights are still widely used in the industry.
2. Colloidal battery
Colloidal batteries are actually an upgraded maintenance free version of lead-acid batteries, which replaces sulfuric acid electrolyte with colloidal electrolyte. They have improved safety, storage capacity, discharge performance, and service life compared to ordinary batteries, and some prices are even higher than ternary lithium batteries. It can be used in the temperature range of -40 ℃ to 65 ℃, especially with good low-temperature performance, suitable for high-altitude regions in the north. Good seismic performance and can be safely used in various harsh environments. The service life is about twice that of ordinary lead-acid batteries.
3. Ternary lithium battery
High specific energy, small size, fast charging, and high price. The deep cycling frequency of ternary lithium batteries is about 500-800 times, and their lifespan is about twice that of lead-acid batteries. The temperature range is -15 ℃ -45 ℃. But the disadvantage is that it is not very stable, and unqualified manufacturers' ternary lithium batteries may explode or catch fire when overcharged or at high temperatures.
4. Lithium iron phosphate battery
High specific energy, small size, fast charging, long service life, good stability, and of course, the highest price. The deep cycle charging frequency is about 1500-2000 times, with a long service life, generally up to 8-10 years. It has strong stability and a wide temperature range, and can be used at -40 ℃ -70 ℃.
