Solar water pumps are directly supplied from solar panels and do not require batteries. A special pump controller ensures continuous and optimal adjustment of the electric energy delivered by the solar panels. Using batteries would result in complicating a straight forward approach. Instead of storing energy in batteries to run the solar pump at times with low irradiation, water is stored in an elevated tank. This has the same effect, water when you need it, with less costs and less complexity! 

Installations of solar pumps in Bénin and Nigeria.