Charging–discharging performance of a 10 Ah lithium-ion battery in a standalone solar-powered terrace lighting system

The object of research: a standalone solar-powered terrace lighting system integrated with a 20 Wp polycrystalline photovoltaic module, a 10 A solar charge controller, a 10 Ah lithium-ion battery, an Arduino-based monitoring unit, and a 10 W LED lighting load.Investigated problem: evaluation of the charging-discharging stability of a 10 Ah lithium-ion battery under real outdoor operating conditions, particularly the ability of the photovoltaic system to maintain sufficient stored energy for nighttime lighting despite variations in solar irradiance, voltage, current, and power.The main scientific results: experimental testing showed that the battery charging current increased with solar availability and reached a maximum value of approximately 1.14 A, while the battery voltage gradually increased from about 11.5 V and stabilized in the range of 12.5-12.6 V. During discharge, the output power decreased steadily from about 9.1 W to about 6.0 W without an abrupt voltage drop, enabling continuous LED lighting operation for approximately 12 hours. The maximum calculated charging power reached 13.71 W at around 13:09 WIB. These results indicate that the integration of a photovoltaic module, solar charge controller, and 10 Ah lithium-ion battery can provide stable daily energy storage and release for autonomous small-scale lighting applications.The area of practical use of the research results: residential buildings, campus facilities, public outdoor areas, terrace and walkway lighting, rural or off-grid locations, and small facilities requiring energy-efficient autonomous lighting based on renewable energy.Innovative technological product: an automatic solar-powered terrace lighting system using a 10 Ah lithium-ion battery and Arduino-based voltage-current monitoring, allowing daytime photovoltaic energy harvesting, regulated battery charging, automatic nighttime LED operation, and performance evaluation based on measured charging and discharging parameters.Scope of the innovative technological product: small-scale renewable-energy lighting systems for residential terraces, building corridors, campus and outdoor areas, rural or off-grid lighting, and educational or laboratory demonstrations of standalone photovoltaic-battery systems.