Design and Performance Evaluation of a Solar-Powered COB LED Lamp with Lithium-Ion Battery Management System for Off-Grid Communities in Nigeria
Abstract
Unreliable grid electricity and low rural electrification coverage remain major development constraints across Nigeria, leaving many households dependent on kerosene lanterns and dry-cell torches for lighting. This paper presents the design, simulation-based sizing, and performance evaluation of a stand-alone solar-powered lamp built around a Chip-on-Board (COB) LED luminaire and a Lithium-ion (Li-ion) battery pack protected by a purpose-built Battery Management System (BMS). The system comprises a 50 Wp monocrystalline photovoltaic (PV) module, a pulse-width-modulation (PWM) solar charge controller, a 3S3P 18650 Li-ion battery pack (11.1 V, 7.5 Ah), a 3S BMS providing over-charge, over-discharge, over-current and cell-balancing protection, a light-dependent-resistor (LDR)-triggered microcontroller for automatic dusk-to-dawn switching, and a 10 W COB LED luminaire with an auxiliary 5 V USB port for phone charging. Component sizing followed standard photovoltaic system engineering methodology using a Port Harcourt solar-irradiance climatology of 4.0-4.5 peak sun hours per day. Simulated and bench-test performance results show a daily energy demand of 64.6 Wh, an average of 8-10 hours of continuous illumination per night, thermal de-rating of the COB LED of less than 12% at a junction temperature of 85 °C, and a total bill-of-materials cost of approximately ₦27,500 (about USD 18) per unit. Compared with kerosene lanterns and imported solar lantern kits, the proposed lamp offers a lower levelised cost of light, a longer expected service life due to the Li-ion chemistry and active BMS protection, and a payback period of under eight months relative to kerosene expenditure. The results confirm that a locally assemblable, BMS-protected, Li-ion solar lamp is a technically sound and economically attractive off-grid lighting solution for rural and peri-urban Nigerian communities.