DIY solar phone charging. Making a mini solar battery for charging your phone. Determining charging parameters

For some reason, phone manufacturers do not want to produce normal self-charging gadgets. The picture above shows a Samsung E1107 phone. According to the manufacturer, in ideal conditions it can be fully charged from the sun in 55 hours. But in Moscow there are no such ideal conditions.

There are more efficient solar panels and lower consumption phones. For example, with a black and white small screen Alcatel ot-117. I have a desire to try to make a solar panel for my phone myself and place it on the back side, on the battery cover.

I have an old one good friend Alcatel ot-117:

Finding a solar panel at a reasonable price with normal efficiency in Moscow turned out to be unrealistic. I bought a Chinese charger.

I bought this charger based on the characteristics. The manufacturer promised a full charge in 14-16 hours under the sun of the built-in 500 mAh battery, i.e. like on my phone. This suited me quite well, since the phone is discharged in 4 days and the power of the solar panel, even taking into account less than ideal conditions, should be enough so that the phone does not need to be charged from a standard charger at all. And all this miracle on Aliexpress costs 150 rubles. Cheaper than buying a solar panel separately in our stores. Moreover, this solar panel is quite efficient.

And so the experiment

We got microusb on one side, and 4 wires on the other:

The solar battery needs to be connected with a red wire to red (plus to plus), and the second wire of the solar battery (mine is blue) with a (-) sign to the black wire. Also, for charging to take place, you need to short-circuit the white and green wires. Wire diagram:

We received this sample for experiments:

It turned out that the phone charges from it, lying on my office desk in sunny weather in 2 working days, and in cloudy weather - in 3 working days. I work from 8 am to 5 pm. The office windows face east. I consider the experiment successful. All that remains is to solder everything under the case directly to the microusb connector and place it in the battery compartment cover. Any additions in the form of diodes and other radio components are not required, since there is no self-discharge when connected to the microusb connector of the phone, and the phone charges naturally. The charging process is displayed on the phone screen. It's amazing how easy everything turns out.

To help, I’m posting a drawing of the microusb pinout:

I ordered a more powerful solar panel on eBay. I also plan to connect it via an SS14 diode (costs 5 rubles) directly to the battery contacts without soldering, simply clamping the contacts. I'll post a wiring diagram later. You will have to wait 3 weeks for the panel. It is 2 times more effective than this one and costs only 100 rubles. I decided to do this because of the constant appearance of an annoying message about connecting and disconnecting charging.

Solar technologies for converting light into electrical energy have become very popular today and their number is growing every day. I suggest you put together a very simple Charger on solar panels with your own hands. You can use it for its intended purpose on any sunny day and charge your mobile phone or Tablet PC. And to create this useful design, you only need the ability to use a soldering iron, a little Money to purchase the necessary components and time.

As mentioned a little above, it will take a little money and time. Everything you need can be purchased very cheaply in Chinese online stores with free delivery to Russia. So, we will need:

Solar cell 6V, 50 mA or any other with more the best parameters. You can buy a universal case, or you can adapt something you already have on hand. Glue, soldering iron and mounting wires.

Open the cover from the universal housing. It already has four slots for screws. Place the cover on the table and carefully make a hole on the left or right for the mounting wires.

A larger hole must be carefully cut in the lower part of the case. The hole must be of a suitable size to secure the socket in it, but keep in mind that the socket must fit snugly in it. Therefore, first cut a small hole and gradually adjust it, trying on the socket. The main thing is not to rush and don’t worry.

Take the solar module and, without unnecessary fuss or haste, place the mounting wires from it inside the housing. This makes it possible to install the battery on top of the case. The next step is to take the car socket and, leading the wires inside through a special hole in the bottom of the case, push it tightly into place.

Using a special tool, I hope you know, connect the red and black wires from the module and the car outlet together.

Hide all the wires inside the case and close the cover, then screw it to the bottom of the universal case and glue the solar module to it. Now on any clear day you can charge your mobile phone without any problems

The circuit shown in the figure below is an excellent and simple automatic charger that can be used to charge 12 volt lead acid batteries from solar panels. You can take any ready-made solar panels, because they can be easily ordered from popular online auctions.

The basis of the microcircuit design is an integrated voltage stabilizer. The BC548 transistor works like, which will disconnect the microassembly from the solar battery when the battery is fully charged.

The scheme compares favorably with other similar ones, which has, which increases low level voltage from solar cells in low light on a cloudy day to the 5V required by a mobile phone. Practical operation of this charger has shown that this design produces an output of up to 100mA.

PC1- three volt solar battery
Capacitors: C1 22 uF, 10 v; C2 100 pF; C3 10 uF, 16 v
Resistors: R1 1.5 kOhm; R2 3.9 kOhm; R3 10 kOhm; R4 180 Ohm; R5 4.7 kOhm; R6 10 Ohm L1 50 to 300 mH
D1 1N5818 Schottky diode
Transistors: Q1 2N4403; Q2 2N4401
J1 is the output jack for your mobile phone

The choke is made from a piece of ferrite rod from the magnetic antenna of CD receivers. We select the number of turns experimentally based on the maximum output current - approximately 20-50.

Using this device, you can get a standard constant voltage of 5 V. The design is recharged from a standard solar battery, inside there are two AA batteries and a stabilizing inverter on the LT1302 chip.

The memory circuit is shown in the figure below:

A solar battery with a voltage of 4.5 Volts and a current of 900 mA is connected to contacts 1-1. When testing the circuit, you need to make sure that the device is capable of charging NiMN from solar energy.

The assembled circuit can be placed in a tin can. Four AA batteries (or 2 lithium) are placed in the free space.

Making a homemade charger is not too difficult - the necessary components are not very expensive and are easy to obtain. Solar chargers USB devices and are ideal for charging small devices, for example, a telephone.

The weak point of all homemade solar chargers is the batteries. Most solar chargers are based on standard nickel-metal hydride batteries - cheap, accessible and safe to use. But unfortunately, NiMH batteries have too low voltage and capacity for them to be seriously considered as chargers for modern gadgets, the energy consumption of which is only growing every year.

For example, the iPhone 4's 2000 mAh battery can still be fully recharged from a homemade solar charger with two or four AA batteries, but the iPad 2 is equipped with a 6000 mAh battery, which is no longer so easy to recharge using a similar charger.

The solution to this problem is to replace nickel-metal hydride batteries with lithium ones.

From this instruction you will learn how to make a solar panel with your own hands. USB charging with lithium battery. Firstly, compared to commercial chargers, this homemade charger will cost you very little. Secondly, it is very easy to assemble. And most importantly, this lithium USB charger is safe to use.

Step 1: Required components to assemble the solar USB charger.

Electronic components:

• 5V or higher solar cell
• 3.7V Li-ion battery
• Li-ion battery charging controller
• USB boost circuit direct current
• Panel mount 2.5mm jack
• 2.5 mm jack with wire
• Diode 1N4001
• The wire

Construction materials:

• Insulating tape
• Heat shrink tubing
• Double Sided Foam Tape
• Solder
• Tin box (or other enclosure)

Tools:

• Soldering iron
• Hot glue gun
• Drill
• Dremel (not required, but recommended)
• Wire cutters
• Wire stripper
• Help from a friend
• Protective glasses

This tutorial shows you how to make a solar powered phone charger. You can refuse to use solar panels and limit yourself to making a regular USB charger using lithium-ion batteries.

Most of the components for this project can be purchased at online electronics stores, but the USB DC boost circuit and lithium-ion battery charge controller will not be so easy to find. Later in this guide, I'll tell you where you can get most of the required components and what each of them does. Based on this, you can decide for yourself which option suits you best.

Step 2: Benefits of lithium battery chargers.

You may not realize it, but most likely you have a lithium-ion battery in your pocket or on your desk, or maybe in your wallet or backpack right now. In most modern electronic devices lithium-ion batteries are used, characterized by large capacity and tension. They can be recharged many times. Most AA batteries are nickel-metal hydride in chemical composition and cannot boast of high technical characteristics.

From a chemical standpoint, the difference between a standard AA NiMH battery and a Lithium-Ion battery lies in the chemical elements contained within the battery. If you look at the periodic table of elements, you will see that lithium is in the left corner next to the most reactive elements. But nickel is located in the middle of the table next to chemically inactive elements. Lithium is so reactive because it only has one valence electron.

And it is precisely for this reason that there are many complaints about lithium - sometimes it can get out of control due to its high chemical reactivity. A few years ago Sony company, a leader in laptop batteries, produced a batch of substandard laptop batteries, some of which spontaneously ignited.

This is why when working with lithium-ion batteries, we must adhere to certain precautions - very accurately maintain the voltage during charging. This instruction uses 3.7 V batteries which require a charging voltage of 4.2 V. If this voltage is exceeded or decreased chemical reaction can get out of control with all the ensuing consequences.

This is why extreme caution must be exercised when handling lithium batteries. If you handle them carefully, they are quite safe. But if you do inappropriate things with them, it can lead to big trouble. Therefore, they should be used only strictly according to the instructions.

Step 3: Selecting a lithium-ion battery charge controller.

Due to the high chemical reactivity of lithium batteries, you must be one hundred percent sure that the charge voltage control circuit will not let you down.

Although you can make your own voltage control circuit, it is better to simply buy a ready-made circuit that you will be confident in its performance. There are several charge control schemes available to choose from.

On this moment Adafruit is now in its second generation of charge controllers for lithium batteries with several available input voltages. These are pretty good controllers, but they are too large. It is unlikely that it will be possible to assemble a compact charger using them.

On the Internet you can buy small modules of lithium battery charging controllers, which are used in this manual. Based on these controllers, I also assembled many other homemade products. I like them for their compactness, simplicity and LED battery charge indicator. As with Adafruit, when there is no sun, the lithium battery can be charged via the controller's USB port. The ability to charge via a USB port is an extremely useful option for any solar charger.

Regardless of which controller you choose, you should know how it works and how to operate it correctly.

Step 4: USB port.

The USB port can charge most modern devices. This is the standard all over the world. Why not just connect the USB port directly to the battery? Why do you need a special circuit for charging via USB?

The problem is that the USB voltage is 5V, but the lithium-ion batteries we will be using in this project are only 3.7V. So we will have to use a USB DC boost circuit that increases the voltage to sufficient to charge various devices. Most commercial and homemade USB chargers, on the contrary, use step-down circuits, since they are assembled on the basis of 6 and 9 V batteries. Step-down circuits are more complex, so it is better not to use them in solar chargers.

The circuit used in this manual was selected as a result of extensive testing. various options. It's almost identical to Adafruit's Miniboost circuit, but costs less.

Of course you can buy an inexpensive USB charger online and take it apart, but we need a circuit that converts 3V (the voltage of two AA batteries) to 5V (the voltage on the USB). Disassembly of conventional or car USB charging will not do anything, since their circuits work to reduce the voltage, but on the contrary, we need to increase the voltage.

In addition, it should be noted that the Mintyboost circuit and the circuit used in the project are capable of working with Apple gadgets, unlike most other USB charging devices. Apple devices check the information pins on the USB to know where they are connected. If the Apple gadget determines that the information pins do not work, then it will refuse to charge. Most other gadgets do not have such a check. Believe me - I tried many cheap charging circuits from eBay - none of them managed to charge my iPhone. You don’t want your homemade USB charger to be unable to charge Apple gadgets.

Step 5: Battery selection.

If you Google a little, you will find a huge selection of batteries of different sizes, capacities, voltages and prices. At first, it will be easy to get confused in all this diversity.

For our charger we will be using a 3.7V lithium polymer (Li-Po) battery, which is very similar to an iPod or cell phone battery. Indeed, we only need a 3.7 V battery, since the charging circuit is designed for this voltage.

The fact that the battery should be equipped with built-in protection against overcharge and overdischarge is not even discussed. This protection is usually called "PCB protection". Search these keywords on the online auction eBay. She is just a small printed circuit board with a chip that protects the battery from overcharging and discharging.

When choosing a lithium-ion battery, look not only at its capacity, but also at its physical size, which mainly depends on the case you choose. I used an Altoids tin box as the case, so I was limited in my choice of battery. At first I thought of buying a 4400 mAh battery, but due to its large size, I had to limit myself to a 2000 mAh battery.

Step 6: Connecting the solar panel.

If you are not going to make a charger that can be recharged from the sun, you can skip this step.

This tutorial uses a 5.5V, 320mA hard plastic solar cell. Any large solar panel will work for you. For the charger, it is best to choose a battery designed for a voltage of 5 - 6 V.

Take the wire by the end, divide it into two parts and strip the ends a little. A wire with a white stripe is negative, and a wire with a completely black stripe is positive.

Solder the wires to the corresponding contacts on the back of the solar panel.

Cover the solder joints with electrical tape or hot glue. This will protect them and help reduce stress on the wires.

Step 7: Drill the tin box or housing.

Since I used an Altoids tin as the body, I had to do a little drill work. In addition to the drill, we will also need a tool such as a dremel.

Before you start working with a tin box, put all the components in it to make sure in practice that it suits you. Think about how best to place the components in it, and only then drill. You can mark the locations of the components with a marker.

After designating the places, you can get to work.

There are several ways to remove the USB port: make a small cut right at the top of the box, or drill a hole of the appropriate size on the side of the box. I decided to make a hole on the side.

First, attach the USB port to the box and mark its location. Drill two or more holes inside the designated area.

Sand the hole with the Dremel. Be sure to follow safety precautions to avoid injuring your fingers. Do not hold the box in your hands under any circumstances - clamp it in a vice.

Drill a 2.5mm hole for the USB port. If necessary, widen it using a Dremel. If you don't plan to install a solar panel, then the 2.5mm hole is not necessary!

Step 8: Connecting the charging controller.

One of the reasons I chose this compact charge controller is its reliability. It has four contact pads: two in front next to the mini-USB port, where constant voltage is supplied (in our case from solar panels), and two in the back for the battery.

To connect a 2.5 mm connector to the charging controller, you need to solder two wires and a diode from the connector to the controller. In addition, it is advisable to use heat-shrinkable tubing.

Fix the 1N4001 diode, charge controller and 2.5mm jack. Place the connector in front of you. If you look at it from left to right, the left contact will be negative, the middle one will be positive, and the right one is not used at all.

Solder one end of the wire to the negative leg of the connector, and the other to the negative pin on the board. In addition, it is advisable to use heat-shrinkable tubing.

Solder another wire to the diode leg, next to which there is a mark. Solder it as close to the base of the diode as possible to save more space. Solder the other side of the diode (without the mark) to the middle pin of the connector. Again, try to solder as close to the base of the diode as possible. Finally, solder the wires to the positive contact on the board. In addition, it is advisable to use heat-shrinkable tubing.

Step 9: Connecting the battery and USB circuit.

At this stage, you only need to solder four additional contacts.

You need to connect the battery and USB circuit to the charge controller board.

First cut some wires. Solder them to the positive and negative pins on the USB circuit, which are located on the bottom of the board.

After that, connect these wires together with the wires coming from the lithium-ion battery. Make sure you connect the negative wires together and connect the positive wires together. Let me remind you that the red wires are positive and the black wires are negative.

Once you have twisted the wires together, weld them to the terminals on the battery that are on back side charging controller boards. Before soldering, it is advisable to thread the wires into the holes.

Now we can congratulate you - you have 100% completed the electrical part of this project and can relax a little.

At this stage, it is a good idea to check the functionality of the circuit. Since all electrical components are connected, everything should work. Try charging your iPod or any other gadget equipped with USB port. The device will not charge if the battery is low or defective. In addition, place the charger in the sun and see if the battery will charge from the solar panel - the small red LED on the charge controller board should light up. You can also charge the battery via a mini-USB cable.

Step 10: Electrically isolate all components.

Before placing all the electronic components in the tin box, we must be sure that it cannot cause a short circuit. If you have a plastic or wooden case, then skip this step.

Place several strips of electrical tape on the bottom and sides of the tin box. It is in these places that the USB circuit and charging controller will be located. The photographs show that my charging controller was left loose.

Try to carefully insulate everything so that a short circuit does not occur. Make sure the solder joints are secure before applying hot glue or tape.

Step 11: Placing the Electronic Components in the Case.

Since the 2.5mm jack needs to be secured with bolts, place it first.

My USB circuit had a switch on the side. If you have the same circuit, then first check whether the switch that is needed to turn the “charging mode” on and off works.

Finally, you need to secure the battery. For this purpose, it is better to use not hot glue, but several pieces of double-sided tape or electrical tape.

Step 12: Operate your homemade solar charger.

In conclusion, let's talk about the correct operation of a homemade USB charger.

You can charge the battery via a mini-USB port or from the sun. The red LED on the charge controller board indicates the charging process, and the blue LED indicates a fully charged battery.

On my last trip, I was able to charge my iPhone 4 to almost 80% on a plane while listening to music. The battery capacity was 2000 mAh. It will take much longer to charge 4400 or 6600 mAh batteries. This especially applies to iPods and other tablets.

Although this is a rather complicated instruction, I hope that you were able to assemble your own USB charger with a lithium-ion battery. Considering that prices for lithium batteries and controllers for them are falling, there is no point in doing homemade charging on other types of batteries. Lithium-ion batteries are especially well suited for projects where the size of the device is critical. Now you can buy lithium-ion batteries in even the most insanely small sizes. This is the best source of energy for autonomous hikes.

Solar battery for charging your phone, tablet, laptop is quite easy to assemble. You will need affordable and cheap components.

There is no need to reinvent the wheel. Factory products consist of 5-6 volt mini-cells, a charge controller and a built-in battery that stores energy. The electrical connection between the individual elements is made through Schottky diodes. These low resistance diodes p-n junction necessary to prevent leakage reverse current between two battery cells.

So, you just need to have:

• several solar panels;
• the same number of Schottky diodes;
• mini USB cable or other cable suitable for connecting to the device being charged;
• charge controller;
• battery with as much capacity as possible.

In order for your mobile phone to reliably charge when the sun hides behind the clouds from time to time, you will need to assemble a panel with an output current of 1000 mA at 5–6 V or 300 mA at 12 V. The more powerful the solar generator, the less you will depend on the open bright sun.

A solar battery without a controller has one drawback - it can drain your phone instead of charging it. In bad weather, the voltage at the output of a homemade device may become lower than that of a mobile phone battery. It’s unpleasant, but current will flow from an already discharged battery to an incorrectly assembled generator.

A car phone charger converts the 7-30 input voltage to a stable 5 volts. Such a device can be used in a homemade project as a charging controller for a phone or tablet.

Yours, collected with my own hands, the alternative energy source produces less than 5 volts. Then use a boost voltage converter. Even if half a volt is generated, then with a step-up stabilizer you can get 5 V. Thanks to it, you can use weak black sockets from garden lanterns. It is possible to assemble a solar battery from transistors. True, transistors in generator mode produce a very weak current, so the phone will charge for at least a week.

You need to solder the assembled battery to the voltage converter directly, without using diodes.

To prevent the converter board from dangling, glue it to the back of the solar panel or push it into its original case.

It is convenient to use a bent one as a stand for a homemade solar battery. bank card or a business card made of thick cardboard.

Having various adapters, you can charge any mobile phone or tablet from a homemade charger.

Now you are independent from outlets, and can enjoy the conveniences of civilization outside the city, in nature, for a long time.

As for costs: one 100 mA solar cell will cost 3–5 dollars, prices for automotive voltage converters start at 2 dollars, and you can actually do without a built-in battery.

DIY USB charger for Ni-Mh batteries DIY charger for lithium batteries How to make a simple Power Bank with your own hands: diagram homemade power bank

Today, technologies that save energy and are environmentally friendly are in trend. Many people choose to use solar panels for a wide variety of purposes. There is always a use for such a device in home use. For example, for the same charging a mobile phone.

Anyone can make such a solar battery charger with their own hands, and our article will help you with this.

Application

Every year summer comes. And this is the time when everyone goes on vacation to the sea or nature. And here it would be completely useful to make sure that everything you need is in place and working properly. And the most popular thing is a mobile phone. As you know, it needs to be charged, and in the forest or in nature this is not always convenient. An excellent solution would be to use a solar-powered charger, which you can easily do yourself.
This device will allow you to:

• don’t worry about charging your smartphone somewhere far from an outlet;
• Do not spend extra money on purchasing such chargers. Purchased models of such devices are quite expensive;
• not be dependent on electricity;
• be constantly in touch and use all the functions of your phone anywhere in your holiday;
• and another plus is the compact size of such a charger;

Note! You can make both a mini charger and a slightly larger device.

• do not carry a lot of unnecessary things with you to recharge electrical appliances.

This DIY mini solar battery has a lot of advantages that will be invaluable during any vacation.

Appearance

The design that a mini solar battery can have with your own hands can be different and, in principle, depends on you. The only thing you need to remember about is the features of use and functionality.

Charging design

It is assumed that such a device is intended for charging cell phone, must be portable so that it can easily fit in a bag or even a pocket. Therefore, a charger of this type is often made foldable. Also, the body of a homemade product must withstand minor mechanical stress. Otherwise, it may simply fall apart in your pocket when moving.
At the same time, there are situations when a solar-powered smartphone charger is intended to be used at home (office, home, etc.) without transportation over significant distances. Then you don’t have to worry so much about the strength of the case.

Note! To add beauty to your homemade charger, you can use various decorative decorations. However, in any case, they should not affect the comfort of using a homemade device.

In order for a device to perform its intended function, a correct assembly diagram is needed. Depending on the type of charging, the circuit may differ slightly.

What we collect

Let's look at how to assemble a mini solar battery with your own hands using the example of a folding charger for a cell phone. This device will have the following characteristics:

Approximate view

• power - 20 watts;
• the design consists of 2 panels (12V - 10 watt). The size of the panels is 30x35 cm, and when unfolded, a homemade solar panel will be 35x60 cm;
• stabilized voltage for output - 14V-20 watts;
• The design has a built-in 14.8V battery – 4.3 ampere-hours. This battery is usually used to power a tablet or laptop;
• two USB outputs, each 5V – 4.3 ampere-hours. As a result, the total is approximately 5V - 8.6 ampere-hour.

As you can see from the photo, the design has the appearance of a diplomat. When closed, it completely prevents any kind of damage to the solar panel.
In essence, such a charger for a cell phone consists of two chargers with 7.4 V batteries built into them - 4.3 ampere hours.
To assemble such a device, you will need:

• two solar panels (in the example, 12V-10 watt panels are used). You can use a variety of models with aluminum frames. It all depends on your financial capabilities;

Note! You can use solar panels made in China. They will cost much less.

• loops. With their help, two panels of our “diplomat” will be connected to each other. They can be removed from the old cabinet. Usually one or two loops are needed;
• batteries;
• USB sockets. We take them from the old system unit. They can also be cut off from the USB extension cable;
• two ultra-bright LEDs. They will be needed to create a charging indication, as well as to illuminate the surrounding area (if there is such a need);
• switches and other small parts.

Some parts for assembly

Since the battery must not be completely discharged, in our homemade device It is necessary to use a battery discharge control unit. It consists of a built-in battery. This battery is switched off in a situation
reducing the voltage on existing lithium batteries (up to 6.1V).
Note! This battery can be easily adjusted to the voltage you need.
The battery can also turn off if there is a short circuit at the output.

Assembly Description

Assembling a charger for any type of smartphone strictly according to the diagram. In our case, the following scheme will be used.

Assembly diagram

Here is a complete assembly diagram for one future charging unit. In this situation, it is possible to parallel the panels to use them as one block.
Note! There are dotted lines on the diagram along which the second panel should be connected to a single stabilization unit.
The circuit is assembled on a body, which can be wooden boards, knocked together like a chessboard or other structures of a similar structure.

Explanation of symbols

As you can see, there are special marks on the diagram that are symbols details. Therefore, in order to correctly connect the components together, you need to know the decoding of these symbols:

• SZ1 – solar panel;
• VD1 and VD2 are diodes. These elements will protect the panel from polarity reversal, which is formed at the input when charging from the network adapter;
• DD1,DD2 - stabilizers. They allow you to achieve a stable voltage when charging;
• R1, R2 are resistors. With their help, the required voltage is set to recharge the batteries;
• R4 is a resistor required to limit the current in the presence of a discharged battery;
• R5 is a resistor. It sets the current flowing through the backlight and display LED;
• R6-R9 - resistors on which dividers are assembled, creating the necessary levels for USB;
• SA1 is a key switch. With its help you can select the mode of use. If the mode is 14V, you can charge the batteries (external lead, etc.), and in the 8.4V mode, you can connect the built-in battery to the circuit. The built-in battery will be supplied with voltage from the solar panel.

Knowing this decoding, you can easily assemble a portable solar charger.

How to use the device

Now that we know how the circuit is assembled, we need to figure out how it will work. If the battery is completely discharged, the device can only be turned on in SA1 8.4V mode. Here, contact group SA1/2 unlocks the battery, and it is connected for charging automatically.

Ready to charge

When the battery is charged, the device will turn on in SA1 8.4V mode if you quickly press the KH1 button. When charging the mobile phone is complete, move SA1 to the 14V position. This will turn off the built-in battery, which will be indicated by the LED turning off.

Conclusion

By following the diagram exactly and correct connection of all its components, you will receive a compact portable device for charging mobile device from solar panels. This homemade charger will allow you to relax comfortably in nature and always stay in touch with civilization.

Details about the motion sensor switch
Selecting a street motion sensor to turn on the lights