Solar pumps are unique in electrical and mechanical designs. Traditional water pumps, without access to a grid power supply, cannot provide a satisfactory performance as they were not designed with energy efficiency as a major concern. In residential areas with mass water supply needs, solar water pumps are required to work as soon as water is in demand, instead of only being used under the sunlight. Thus, an energy storage back-up power is necessary to meet demands. In consideration of weather, electricity-availability and other factors, it is best for a solar water pump to be equipped with a powerful lithium ion back-up battery. CSDWELL can provide the optimal lithium ion battery solution for solar water pumps in the open air.