Solar street light battery

Solar street light battery

Now the preferred lighting fixtures in China and aboard are solar street lights. Solar street lights can be installed everywhere in towns and villages. Everyone knows that batteries are one of the most important components of solar street lights. In fact, the batteries is a mainly part of  solar street lights on the market. There are four kinds of lead-acid batteries, gel batteries, ternary lithium batteries, and lithium iron phosphate batteries, so which battery is the best?

First, let's take a look at the characteristics of these batteries:

1. Lead-acid batteries: 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 low specific energy (that is, the electric energy stored in each kilogram of the battery), so the volume is relatively large, the service life is short about 300-500 deep cycles, and the daily maintenance is frequent. At present, solar street lights Industry is still heavily used.

2. Gel battery: It is actually an upgraded maintenance-free version of lead-acid battery. It replaces sulfuric acid electrolyte with colloidal electrolyte, which is better than ordinary batteries in terms of safety, storage capacity, discharge performance and service life. Improvement, the price is even higher than the ternary lithium battery. It can be used in the temperature range of -40℃--65℃, especially the low temperature performance is good, suitable for the northern alpine region. It has good seismic performance and can be used safely in various harsh environments. The service life is about double that of ordinary lead-acid batteries.

3. Ternary lithium battery: high specific energy, small size, fast charging and high price. The number of deep cycles of the ternary lithium battery is about 500-800 times, the life span is about 1 times longer than that of the lead-acid battery, and the temperature range is -15℃-45℃. But the disadvantage is that it is not stable, and the ternary lithium battery of unqualified manufacturers may explode or catch fire when it is overcharged or the temperature is too high.

4. Lithium iron phosphate battery: high specific energy, small size, fast charging, long service life, good stability, and of course the highest price. The number of deep cycle charging is about 1500-2000 times, the service life is long, generally 8-10 years, the stability is strong, the operating temperature range is wide, and it can be used at -40℃-70℃.

The role of the special battery for solar street lights in solar street lights is beyond doubt, and the rationality of the battery capacity configuration directly determines the use effect of solar street lights.   

Lithium battery is now the first choice of our solar energy manufacturers, it has many advantages, which are embodied in

1. Environmental protection, lithium batteries are not polluted (not absolute), while lead-acid batteries are polluted by heavy metal lead

2. Safety, power-type lithium batteries (lithium manganate, lithium iron phosphate) have different safety materials. The lead-acid battery technology is quite mature, and its safety is higher than that of lithium batteries.

3. Specific energy, the mass ratio and volume ratio of lithium batteries are about 40% higher than that of lead-acid batteries.

4. In terms of price, the price of lithium batteries of the same capacity is more than double that of lead-acid batteries.

5. Service life, the current general lithium iron phosphate is charged 1500 times without recall effect. After 1500 times of charging, the storage capacity is about 85%, while the lead-acid battery is about 500 times, and the memory effect is remarkable.

6. Self-discharge rate, the monthly self-discharge of lithium battery is less than 3%, and the lead-acid battery is 15~30%, the difference is significant.

7. Discharge characteristics, to put it simply, the battery of the same capacity, in the case of high current discharge, the lithium battery discharges about 30% more electricity than the lead-acid battery.

8. Voltage channels, lithium battery voltage channels are > 3V, lead-acid batteries are 12V.

But things have two sides. Lead-acid batteries are relatively safe and stable, while the safety of lithium batteries is still a problem due to the high activity of lithium metal itself.

In summary, although lithium batteries are relatively active, they have advantages in performance and various aspects, so from the perspective of economy, performance and service life, almost all users and integrators will choose lithium batteries.