I`m working on a solar USB charger project and need some help on how to connect a 9V 2W solar panel, 4 AA battery, USB and digital voltmeter. The USB is for load (smartphone charging).
Four 1,5v rechargable alkaline batteries in series is 6v, so I use a LM7806 regulator after the 9v panel, and then a diode to prevent the batteries from discharge into the solar panel. The voltmeter is for controlling the status of the batteries so I don`t overcharge them. How do I connect this together? Do I need to limit the current from the panel?
Four 1,5v rechargable alkaline batteries in series is 6v, so I use a LM7806 regulator after the 9v panel, and then a diode to prevent the batteries from discharge into the solar panel. The voltmeter is for controlling the status of the batteries so I don`t overcharge them. How do I connect this together? Do I need to limit the current from the panel?
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