Solar Mobile phone charger

Good day All,

I have got a new 12volt, 5W, solar panel. I have planned to start a new project on solar mobile phone charger.
I dont know how to get/build a circuit.

I want to charge 2 or more mobile phones at the same time as my solar panel is bigger in size and capacity.

If possible, I want to charge a 12volt lead acid battery with this. Can any one pls give a detailed circuit and electronic components with rating for this solar panel (5W,12Volt).

Thanks in advance sir.

how much AmpHour for your lead acid battery ?

Gozaki said:

how much AmpHour for your lead acid battery ?

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I haven't decided yet. Mostly it is 42AH, 12 V battery.

Probably this battery should supply some LED lights.

Pls reply back with some simple yet working circuit. thanx in advance.

Solar panel Voltage 12V
Power rating 5W

So you can charge 5/12 = 416 mA

All the mobile batteries are around 3.6V

Use regulator circuits or use 7805 regulator and use a USB Mobile charger

With this panel, it takes much more time to charge a 42AH battery. i.e more than two days

Use more no. of panels to increase your charging current (by connecting them in parallel)

You can use this solar panel to charge lead acid battery or two smaller in parallel over day, and that battery/ies will give charging power at night for phones. I mean on lead acid 7Ah.

Between solar panel and battery/ies put shotky diode. Maybe diode is already builtined.

Your panel is not strong you can use it without current control, just control voltage with some voltage regulator to 13,8V float charge. You can use LM338T (TO220) 5A with small heatsink or LM317 (TO220) with good heatsink. Solar panel OCV should be about 17V-19V.

For each phone charging channel use 78S05 voltage regulator. You can charge car navigation and other devices over this. Just get connectors and make some docking station for devices.


This panel can charge and maintain car battery each day, when car is parked longer time.

More care about the wattage rating. You can't extract power above 5W from this single panel.

lalgpt said:

More care about the wattage rating. You can't extract power above 5W from this single panel.

Click to expand...

This is declared factory power at maximum conditions.