The reliability of telecommunication services depends on the provision of a reliable and stable power supply. The lead-acid battery, as the primary storage medium for this power supply, has long been a faithful servant. Often ignored because of their apparent simplicity, lead-acid cells have been developed over many years to a stage where the positive pasted plate pure lead cells now have an excellent record of operational performance. An understanding of technical considerations of batteries in telecommunication service is vital. This understanding, including the requirements for storage in solar photovoltaic systems, underscores the design that has brought the lead-acid battery to the present advanced state.