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@article{203871,
        author = {Pranav Tammewar and Ram Badrinath Narwade and Priyanka Kisan Jadhav},
        title = {Solar power bank},
        journal = {International Journal of Innovative Research in Technology},
        year = {2026},
        volume = {13},
        number = {1},
        pages = {575-581},
        issn = {2349-6002},
        url = {https://ijirt.org/article?manuscript=203871},
        abstract = {The widespread dependency on smartphones and portable electronic devices has made grid-independent charging a practical necessity, especially across semi-urban and rural India where electricity supply remains inconsistent. This paper presents the design and hardware prototype implementation of a compact, smartphone-sized solar-powered portable power bank. The system harvests solar energy through a photovoltaic panel, manages lithium-ion cell charging using a TP4056 constant-current/constant-voltage (CC/CV) linear charger IC, and delivers a regulated USB output through an MT3608 step-up boost converter. A 3.7 V / 2200 mAh 18650 lithium-ion cell serves as the energy storage element, storing 8.14 Wh of energy. Reverse current flow from battery to solar panel is blocked by 1N4007 rectifier diodes, and a push-button switch controls the output stage. Prototype testing measured a USB output voltage of 5.12 V, which is within the USB 2.0 specification range of 4.75 V to 5.25 V. Theoretical analysis shows the prototype can deliver approximately 1380 mAh of usable charge at 5 V output, accounting for boost converter losses. All subsystems are assembled from commercially available off-the-shelf modules, making the design cost-effective and readily reproducible for academic and educational purposes.},
        keywords = {Solar Power Bank; TP4056; MT3608 Boost Converter; 18650 Li-Ion Battery; Solar Energy Harvesting; Portable Charger; CC/CV Charging; Reverse Blocking Diode; USB Output.},
        month = {June},
        }