Which Lithium Battery is better for solar street light?

Importance of Solar Street Light Battery

Solar street lights are a new and sustainable type of street light that many governments, cities, communities, and parking lots prefer to use to efficiently light up their roads.

In order to run smooth operation, these street lights need powerful batteries. These solar rechargeable batteries store the energy produced by the sun during the day for use at night.

The quality of the batteries largely determines the effectiveness of the entire solar lighting system

For a long time in the past, solar street lights mainly used GEL batteries. However, the installation process of such batteries is complicated because they need to be buried in the ground, which makes them easy to the risk of theft.

In addition, the service life of the GEL battery is relatively short, only about 5 years. Therefore, a new type of lithium battery gradually replaced the GEL battery.

Nowadays, lithium battery solar street lights have become the mainstream of the market.

Perhaps when you are purchasing, different solar street light manufacturers will offer different lithium batteries to you, so the lithium battery used in solar street lights, in the end, which is better?

In this article, we will make a comparison from the cycle life, safety performance and high and low temperature performance, and Overcharge and discharge performance of different lithium batteries to see which lithium battery is more suitable for your project's usage scenario.

Types of Lithium Battery

First of all, let's first understand some of the classification of lithium batteries for solar street lights: Ternary lithium batteries and Lithium iron phosphate batteries.

What is ternary lithium battery?

Ternary lithium battery refers to the lithium battery containing nickel cobalt and manganese three elements of the transition metal embedded lithium oxide compliant material cathode.

This material synthesizes the advantages of lithium cobalt, lithium nickel and lithium manganese three materials, the formation of three materials three-phase eutectic system, due to the ternary synergistic effect of its comprehensive performance is better than any single combination of compounds.

High energy density is simply understood as small size and large capacity. The rated voltage of single cell is 3.7V, single cell can be connected in parallel to form 11.1V battery pack. Widely used with notebooks, cell phones, portable digital products.

What is LiFePO4(lithium iron phosphate) battery?

Lithium iron phosphate battery is a kind of lithium-ion battery using lithium iron phosphate (LiFePO4) as the positive material and carbon as the negative material, the rated voltage of single cell is 3.2V, and the single cell can be connected in series to form a 12.8V or 25.6V battery pack. Widely used with solar energy storage, solar street light, new energy vehicles and so on.

Battery Performance Comparison

Cycle life:

In the standard laboratory, 25 ℃, 1C charging and discharging current test environment

Lithium ternary battery: theoretical cycle life 1000 cycles

Lithium iron phosphate battery: theoretical cycle life 2000 cycles

Safety performance:

Lithium ternary batteries: around 200 degrees will decompose, very easy to spontaneous combustion and explosion, safety is poor

Lithium iron phosphate battery: 700 degrees before decomposition, no spontaneous combustion and no explosion, high safety performance.

Therefore, so far the explosion of solar street lamps are basically used ternary lithium batteries.

High and low temperature performance:

Ternary lithium batteries: when the temperature is lower than -20 ℃, the capacity can still reach about 70% of the nominal capacity. But when the temperature is too high, there is a risk of spontaneous combustion and explosion.

Lithium iron phosphate battery: Generally speaking, when the temperature is lower than 0 ℃, the active substance inside the battery decreases, which greatly reduces the capacity and discharge ability of the battery.

At high temperatures, the battery will not spontaneously combust.

Overcharge and discharge performance:

Lithium ternary battery: When the battery is overcharged and overdischarged, the damage to the battery life is huge. When the battery is overcharged to 0V, the battery will be scrapped.

Lithium iron phosphate batteries: a short period of overcharge and overdischarge, the impact on battery life is not great, even if the overcharge to 0V, can be restored to normal, but of course, the performance will be slightly reduced.

Through the above comparison of the two kinds of batteries, I think you will be very easy to find the lithium battery solar street light suitable for your project use scenario.

Summarize 

Compared with lithium iron, the advantage of lithium ternary is good low temperature performance, so the solar street light with lithium ternary battery is more suitable to be installed in low temperature areas.

Contrary to ternary, LiFePO4 Battery can have better safety in relatively high-temperature environments, so lithium iron phosphate solar street lights are more suitable for high-temperature areas.

There are also higher security requirements in the region, such as gas stations near the industrial zone with flammable and explosive substances and other areas, it is recommended to use lithium iron phosphate battery.

Which lithium battery for solar street lights is better for your projects? Do you still have questions? If there are still unclear points, welcome to contact us. Our professional engineers will customize the right lighting solution according to your project requirements so that you can get more orders.