Simple Solar Battery Charger Circuit

This article show how to make charger which uses sunlight to charge 12V battery like in car or some toy.

Normal charger need electricity but this one uses solar panel which is good in place where there is no power.

We call this circuit Simple Solar Battery Charger Circuit

It take sun energy and charge battery for phone, laptop, car battery, lamp, fan and more.

This charger does not plug direct to device.

It is having one battery inside and that battery keep solar power like small juice box.

Later this power is used to charge our stuff with help of one part called capacitor.

If anyone wants to know how it work and how to make?

Okay, then go and read more in this article.

What is a Solar Battery Charger Circuit:

Simple solar battery charger is small device it charges battery using sunlight.

This is an easy idea for solar panel to take sunlight it changes it to electric power and then battery gets charged.

Solar Battery Charger Circuit Diagram:

Parts List:

Circuit Working with Formulas:

Solar panel have one special part called photovoltaic cell, it changes sunlight into electric power when sun hit it.

We have used one IC chip called LM317 and one knob resistor potentiometer to control voltage.

We get output voltage using this formula:

Vout = 1.25V × (1 + (R2 / R1))

where:

• Vout is the voltage we want.
• R1 connect to adjust pin on LM317.
• R2 connect between output and adjust pin.

Reverse Supply Protection:

We used one diode Schottky, 3A 50V to stop reverse power going back.

Diode work like this formula below:

I = Is [V / (enV/n.Vt – 1)]

where:

• I is current through diode.
• Is is small reverse current.
• V is voltage across diode.
• n is around 1 for Schottky diode.
• Vt is small voltage which is about 0.026V at room temp.

This help understand how voltage and current move in the circuit and these formulas help to check if circuit is working good.

Using 12V power we can charge many electronics device.

Many devices work fine with this kind of voltage.

How to Build:

To build a Simple Solar Battery Charger Circuit follow the below mentioned steps:

• Take solar panel wire positive (+) and negative (–) and connect them to input pin of LM317 chip.
• Be sure solar panel gives more voltage than what battery need.
• Now connect LM317 output pin to positive side of capacitor.
• Then connect capacitor negative side to batteries negative (–) side.
• Take one side of potentiometer and connect to adjust pin on LM317.
• Other side of potentiometer connects to capacitors negative (–) side.
• Middle pin of potentiometer is for setting exact voltage we want.
• Use LM317 formula before to find resistor values if needed.
• Now take Schottky diode and connect anodes flat side to batteries positive (+).
• Connect cathodes side with line to LM317 output pin.
• If we want to show charging then add one LED with resistor and put it across output side in parallel.
• Fix all parts nicely on breadboard or PCB
• Check all wire and solder properly so there is no short circuit happen.
• After all is done connect it to solar panel.
• Put solar panel under strong sunlight.
• How fast or well battery charges depends on LM317 setting and solar panel power.

Application and Uses:

Solar battery charger have many uses like:

Charge things like laptop, mobile phone and other small electronic stuff.

Help people charge devices easily even when no power plug is there and is good for travelling, camping or going to remote place.

Conclusion:

This Simple Solar Battery Charger Circuit is an easy way to take sun power and make it charge our daily devices is using small solar battery charger.

If we follow steps and learn how it work can make our own good charger for phone and other things.

References:

Designing a Solar Cell Battery Charger

Design of a solar powered battery charger