The fluctuation of solar radiation intensity caused fluctuate energy received by photovoltaic (PV) systems. Meanwhile, the electricity usage from PV systems is depending on a difference needs every time. These conditions can be influence on PV systems performance after use for some period. Currently, there are six of 50 Wp of standalone solar lighting systems (SLS) installed for cow-stable lighting purpose in Sleman, Yogyakarta. The aims of this research are to investigate the performance of SLS, especially in the solar modules and their batteries after one year period of operation. The physical conditions of all SLS’s component are checked. The load consumption time, the output voltage of solar module, and the battery voltage after charging and discharging are measured for each SLS. The data are used to analyze the average daily energy and the battery performance. Then the SLS which has the lowest performance is continued to investigate with maximum time loading. According to the test result, the physical conditions of SLS’s components are good but all of the components were dirty and the water in the batteries was low level. Overall, the SLS have been well-operated and the maximum DOD is 18.61%. Furthermore, the sixth SLS indicates that its battery have highest energy losses because the DOD is high, whereas the energy consumption, performance ratio, and battery efficiency are low. It appears that the basic problem is low maintenance. To maintain the SLS’s performance it needs to improve the quality of maintenance system.