Circuit Diagram
How to Build It
- Connect the solar panel's MC4 connector to an input cable.
- Connect the panel's positive output through a 1N4007 diode (anode toward the panel) to the battery's positive terminal.
- Connect the panel's negative output directly to the battery's negative terminal.
- Expose the panel to strong light (sun or a bright lamp) and measure the charging voltage at the battery with a multimeter.
- Cover the panel — the diode should prevent the battery from discharging back through the panel.
Bill of Materials
| Product | Code | Qty |
|---|---|---|
| Li-ion cell 18650 3.6V/4200mAh with terminals | 13 278(13 261) | 1 |
| Connector (general) | 2-2270025-1 | 1 |
| Diode/bridge rectifier | 1N4007-DIO | 1 |