This guide is applicable to all stand-alone photovoltaic (PV) systems where PV is the only charging source. Stand-alone PV system parameters and operating conditions are discussed in relation to battery characteristics and expected system performance. Charging parameters for PV systems are suggested to help in the selection of a battery for a specific application. Finally, a performance test to verify the battery selection and system parameters is provided, including discussions on how to interpret test results. Test results only provide information on initial battery performance. No cycle-life predictions are made.