In off-grid scenarios such as field surveys, remote mountainous areas and outdoor base stations, 12V100Ah lead-acid batteries can form off-grid energy storage systems with photovoltaic modules to realize clean energy reserve and emergency power supply. It stores electric energy through solar charging in the daytime and continuously outputs power at night or on rainy days without sunlight, supplying power for outdoor monitoring equipment, surveying instruments, outdoor lighting and small communication devices. With strong environmental adaptability and high and low temperature resistance, it adapts to complex outdoor open environments. The maintenance-free design greatly reduces outdoor operation and maintenance costs, and its sufficient capacity and long endurance perfectly meet the long-term emergency power demand in non-grid coverage areas.