Off-grid photovoltaic systems are the core application scenario of lead-acid batteries, which effectively solve power supply problems in off-grid areas. In mountain villages, field monitoring, photovoltaic irrigation, remote base stations and other scenarios, solar power cannot be connected to the grid. Lead-acid batteries can efficiently store excess daytime power for peak-shaving power use. Suitable for low and medium-power off-grid photovoltaic equipment, they have good startup performance and can quickly respond to dynamic changes in solar power generation. Compared with new energy storage batteries, they feature stronger environmental adaptability, stable operation in high and low-temperature outdoor environments, and strong resistance to complex working conditions. With convenient installation and high compatibility, they require no complex supporting equipment, greatly reducing the construction difficulty of off-grid photovoltaic projects.