What Kind of Batteries are Used in Solar Street Lights?
One question that always delves into the minds of people when they switch to a solar street lights system is about the type of battery that will be used to power the solar street lights. Every user wants to get the best battery for their new solar light system that can save money, last longer, and requires the least amount of maintenance. With so many options out there in the market, some using confusing languages makes the choice difficult. It is important to know the kind of batteries, specifications, and their usage beforehand.
Knowing that all batteries are nor created equal, and many batteries are better in performance than others and some batteries in the market carry some danger to their operation. Let’s get into the kinds of batteries present in the market and some information about its specifications and battery profile.
|Battery Type||Size||Nominal Voltage||Voltage of Battery Set||Cost||Working temperature||Cycle Life|
|Lithium-Ion (Li-ion)||18 x 65 mm||3.7V||12V||Cheaper in price||-30 to 65 Celsius||800 times|
|Lithium Iron Phosphate (LiFePO4)||26 x 65 mm||3.2V||12.8V||More expensive||-10 to 75 Celsius||2000 times|
|Lead Acid Battery||90 x 70||2V||12V||Cheaper in price||-20 to 5o Celsius||300 times|
Lead Acid Battery:
People widely prefer using this battery because of the price advantages. It is inexpensive as compared to other batteries. However, there are some disadvantages compared to Li-ion and LiFEPO4. It needs frequent maintenance, the risk of explosion is high, and due to the presence of lead, it has some environmental concerns. The life of the battery is somewhere between 3 -4 years.
Another big disadvantage of lead-acid battery is that it needs a bigger solar panel for charging. The solar panel will have to generate at least 12 V to charge the battery. The battery size requirement for solar light application is not cost-effective. They are costly to manufacture which defeats the purpose of using inexpensive solar lights.
Li-ion is a compact and high priced battery. It requires a 3.7 V of power for charging. Which means the requirement of solar panel size is smaller. Even during cloudy days, the solar panel can still produce a 3 V and charge the battery.The life cycle of the battery is 4-5 years and it requires no maintenance.
One downside is that it is not favorable to extreme weather conditions. One of the kinds of lithium ion battery is the ternary lithium-ion battery. It uses Ni-Co lithium manganate as the positive electrode and graphite as the negative electrode material. The voltage platform of ternary lithium ion battery is very high, which means that the specific energy and specific power of it are larger under the same volume or weight. The ternary lithium battery is a 3.7V voltage platform, and the cycle life depends on different manufacturers, different models, and processes, and generally, it is 500-800 charge cycles. Below is the picture of ternary lithium ion battery pack.
Lithium Iron Phosphate Battery:
LiFEPO4 battery is a compact and priced higher compared to lead-acid and Li-ion battery. It is one of the most advanced battery types available in the market. It requires 3.2V of power for charging which means the requirement of solar panel size will be smaller.
The life cycle of the battery of 6-10 years and requires no maintenance. Another advantage of this battery is that it can withstand extreme weather conditions.
How these batteries are used?
Lead acid batteries are generally used for lighting home and emergency conventional lights. Li-ion and Lithium-ion phosphate batteries are the best options for the solar lighting systems, especially used in all in one lighting system like solar street lights.
One of the important things to look out for in the battery is its capacity. Since the capacity is the measurement of the quantum energy that is stored in the battery.