There are many battery types which can be used in solar lights. Below are the widely used rechargeable battery for solar lights.
- Lead–acid battery and SMF
- lithium ion battery or Li-ion
- lithium ion battery phosphate or LiFePO4
Lead-Acid Battery and SMF
Lead acid battery is the most widely used batteries because of it price advantage. It is inexpensive compared to new technologies batteries. But there are many disadvantages compared to Li-ion an LifePO4. It need regular maintenance, Risk of explosion is more, there are lot of environment concerns as it has lead and it would be difficult to handle extreme weather conditions. Life of the battery is around 3 – 4 years.
Two of the biggest disadvantage of using lead acid battery is it needs a bigger solar panel for charging and size of battery is bigger and requires lot of space. Solar panel has to generate at least 12 V to charge the battery. That means during cloudy days it would be not possible to generate 12 V.
Lithium Ion Battery or Li-ion
Li-ion battery is compact and priced higher compared to Lead-acid battery. It requires 3.7 V of power for charging. That means solar panel size can be smaller. During cloudy days’ solar panel can generate 3.7 V and these batteries can be easily charged.
These batteries require no maintenance and life of battery will be 5 - 6 years. Only disadvantage is there might be chances of explosion in extreme weather. Li-ion batteries efficiency reduces during Very high or very low temperatures.
Lithium Ion Phosphate Battery or LiFePO4.
LiFePO4 battery is compact and priced higher compared to Li-ion. It is most advanced battery type currently available in market. It requires 3.2 V of power for charging. That means solar panel size can be smaller. During cloudy days’ solar panel can generate 3.2 V and these batteries can be easily charged.
These batteries require no maintenance and life of battery will be 9 - 12 years. Advantages of using this battery is it can with stand extreme weather conditions. Hence this is most safer battery.
Usage of Batteries in Solar Lights.
Lead acid batteries are widely used in home lighting system and emergency solar lights. Li-ion and LiFeP04 batteries are used for integrated solar light system. All in One lights like, Solar Garden Lights, Solar Street Light, Solar Flood Lights etc. uses these battery types.