We collect power bank. Homemade power bank with solar battery

External batteries (Power Bank) are used to charge portable mobile devices. They are convenient to use on camping trips or on vacation, when it is not possible to charge a mobile phone from a network or computer. But what if you live far away from specialty stores or just don't want to spend money on buying an external battery? In this article we will tell you how you can make a Power Bank yourself from improvised means.

How to make a Power Bank with your own hands?

To make a homemade external battery, you do not need to buy any expensive parts, all of them can be found at home.

So, we need:

AA nickel batteries, 4 pcs.
. USB connector.
. Air freshener bottle.
. Film box.
. Wires.
. Matchboxes, 2 pcs.
. A jar for vitamins (or any other appropriate size).
. Staples.
. Metal wire.

Let's start making!

1. We glue the matchboxes together, cutting off and bending one of the walls from each of them (as in the photo). We put batteries in them.

2. Using brackets, we make contacts on the back of the box and connect them with wire.

3. The result was a design with a voltage of just over 5 volts, which is quite enough for charging mobile phone. We put it in a film box and seal it so that nothing dangles.

4 . We cut off the bottom of the jar of vitamins, make a hole in it and insert a USB connector (if there is no jar of vitamins, you can use any other lid, the main thing is that it fits as a lid to the air freshener bottle). Solder to USB cable, connect it to the battery and close the box.

5. So that our Power Bank lasts a long time and does not crumble at the first shaking, we put it in an air freshener bottle.

This is a very useful device, especially if you are a frequent traveler, and can be made very quickly and cheaply by hand. There are a lot of ready-made devices and cases for 18650 batteries, but for various reasons they all did not suit us and we decided to make our own.

Features of Power Bank

The idea of ​​our charger is very simple. This is in some way a case for 18650 LiIon batteries with the ability to quick change this battery. The device can both charge the battery itself and charge external devices. And all this, in accordance with the original plan, was to have a minimum size, low cost and the utmost simplicity of the device until everyone could assemble it themselves. And as a result, we got a fairly successful design:

Firstly, this approach saves you from deciding on the battery capacity you need. Our PowerBank allows you to carry as many spare batteries as you need in a given situation.
Secondly, batteries of this format are widely distributed and available. We do not recommend such actions, but they can even be found conditionally free of charge in old technology.
Thirdly, such universal solutions simply do not exist, or they are very expensive. And the main complaint is primarily about the size of ready-made solutions.

Assembly accessories

A complete list of everything you need:

1. 18650 battery holder for PCB mounting
2. Battery charge controller. It has built-in protection and can charge the battery with current up to 1A
3. StepUp Charging Converter external devices current up to 0.5A
4. Rocker switch (photo with dimensions)
5. Screw M3x6 with countersunk head - 2 pcs
6. Nut M3 square - 2 pcs
7. Mounting wire and heat shrink tube
8. Printed case (download link will be at the end of the article)

That is, the cost (including shipping!) Is approximately $4.

Wiring diagram

Everything is connected very simply, with five wires:

First you need to solder the wires and the switch to the charge board. It is important that the wires from the "B+" and "B-" contacts must be long, and the wires from the "OUT+" and "OUT-" contacts must be made short.

The board is then installed into slots inside the case. It is specially made very tight so that in the future the board does not hang out in it.

Now you can install the boost converter board into its slots and then solder the short wires from the battery charge controller to it, which go through the switch from the "OUT +" and "OUT-" contacts. It is important not to confuse the polarity anywhere, but everything is quite well and intuitively located there.

After that, you can shorten the wires going to the battery, solder them to the battery holder and install the nuts in the grooves. At the same time, observe the polarity of connecting the wires with the polarity on the battery holder and on the ends of the housing!

At this stage, you can already install the battery and check that the device is functioning normally. If everything works fine, then you can additionally fix the boards in the case with the help of tremoglue, but even without this they are held very tightly.
It remains only to screw the holder to the case with screws:

Video

Results

The whole device has dimensions of 79x26x31mm, while the battery diameter is 18mm and the length is 65mm. The charger weighs 25g without battery and 75g with battery.
The components that we used are used very widely and in some way have already proven themselves. We just combined it all into one complete product that anyone can make for themselves. And in our opinion, we quite succeeded in making it minimalistic and quite suitable for everyday use both for charging the batteries themselves, and for use as a PowerBank.

Download links

File for printing the body on a 3D printer.

We will be very happy if you support our resource and visit our store.

Once again, the topic of the article is devoted to PowerBanks. Today you can see a simple good circuit without any microcircuits, only on transistors.

The circuit is a simple stabilized step-up, which is able to increase the voltage from a power source, for example, from a lithium battery, to a level of 5 V. This voltage will already allow you to charge tablets and smartphones.

Of course, such a boost converter module can be purchased in China for about $ 1, but the operation of a device assembled by oneself brings much more pleasure. In addition, this scheme practically does not require any financial costs, and you do not have to wait a month, as in the case of ordering goods from China.

A few words about the scheme and the principle of its operation.

There is a multivibrator as a pulse generator. In the presented version, it is tuned to a frequency of about 30 kHz.

The principle of operation of the scheme does not differ from its relatives. The initial pulse from the multivibrator, entering the base of the composite transistor, opens it. At the moment the transistor closes, self-induction EMF pulses arise from the inductor, which are rectified by the fast diode D1 and smoothed out by the capacitor C1. The output voltage is stabilized, and it is set by selecting the Zener diode VD1.

Transistor VT2 opens when the output voltage from the converter exceeds the specified stabilization voltage. The base of the transistor VT1 is shorted to ground through its open junction. As a result, the latter is closed.

Coefficient useful action this converter can reach up to 70-75%. And this is very good. But in order to achieve such efficiency, you will have to spend more than one hour rewinding the throttle, because a lot depends on it.

The maximum current value that could be obtained at the output was about 1 A. The stabilization works as it should. The device is suitable for real use.

A lot of time was also spent on the creation of the board. It is compact and looks very nice.

You can download the board at the end of the article.

It's time to talk about the element base and circuit setup. Transistor VT1 is recommended to take composite. The experiments were carried out with different transistors, but in the end the most suitable ones turned out to be KT829, KT972 or something from imported ones, for example, BD677, etc.

The inductor is wound on a dumbbell-type ferrite core. It was removed from the computer power supply board. You can also use powdered iron rings or rod core. The number of turns and the diameter of the wire were selected through experiments. Ultimately, the choke was wound with 8 mm wire (deviation up to 20% is possible). The number of turns was 25.

Adjusting the converter is reduced to obtaining the desired output voltage and the minimum current consumption at idle. In the described example, the minimum no-load current is 40 mA and depends on the inductor. This is a lot when compared with ready-made Chinese modules. But nothing can be done - you should not expect more from a banal multivibrator.

The stabilizer is also subject to selection. The stabilization voltage is selected in the range of 4.7-6.2 V. In the example, a zener diode of 5.1 V is used.

The composite transistor is still bipolar, and it can be heated during operation, so a small heat sink in the form of an aluminum sheet will be very useful.

Do not forget to check the device for operability. The wattmeter on the Chinese USB tester is a little "buggy" - the real voltage is approximately 5 V and can "walk" in a small limit, which is completely normal. The charge current will also change.

Now take a look at the design of the PowerBank as a whole. The converter is powered by two 18650 (Li-ion) batteries connected in parallel. They were removed from the laptop battery. The working capacities of both should be as close as possible to each other.

Also, the batteries were supplemented with a protection board that turns them off when the voltage drops below 3.2 V. .

To do this, the following charge board is involved in the device:

Such boards already come with a battery protection circuit. Such boards are easier to buy than to make, because their price is only 30-50 cents.

Now assembly. The first step is to prepare the batteries. Soldering them is undesirable, but possible. The main thing is not to overheat.

The number of batteries can be any. In the example, there are 2 of them. The larger their capacity, the longer the PowerBank's operating time. All batteries are connected in parallel.

The PowerBank case came from an old laptop power adapter.

It remains to place all the details in the case, add a power switch, bring out the USB connector for charging phones, miniUSB for charging the PowerBank itself, and also bring out a couple of LEDs that are on the controller board. One of them lights up when charging is in progress, and the second lights up when it is completed.

Attached files: .

Charging device for lithium batteries do it yourself

Good day Dear friends! In today's article, I would like to show you how to make a camping portable charger for phone - Power Bank. Its camping qualities lie in the fact that it can be charged with the help of solar energy. This Power Bank will cost quite cheaply, since secondary batteries and cheap Chinese components from online stores will be used in its assembly. Oh well, enough long prefaces, let's go!

And so, for this homemade product we need:
- 18650 batteries.
- Cassettes for batteries.
- Wires.
- Power Bank control board (can be bought from the Chinese).
- Fiberboard or MDF panels (you can also use plastic, as this will come in handy for the Power Bank case).
- Solar panel (battery) 5V.
- Switch.
- Thin plastic tube.

Of the tools we will also need:
- Soldering iron.
- Super glue.
- Screwdriver.
- Pen (or pencil, marker, etc.).
- Stationery knife.
- Drill.
- Thermal glue.

Before you start building a Power Bank, you should deal with rechargeable batteries. It was decided to use 18650 batteries, since this is the most common battery format and it will be easy to find a control module for them in Chinese online stores. You can buy these batteries new, which is very good, but you can save money and get these batteries from an old laptop, just like the DIY author did. But you must understand that the use of old batteries power characteristics Banka will not be very good, there will be slow charging, small capacity, etc.

We turn to the assembly of batteries into one battery. Our battery will consist of four batteries. In order to assemble several batteries into one, we need special cassettes (photo below), of course, you can tie them with electrical tape or glue them with thermal glue, but using cassettes will be much more convenient.

We insert the batteries into the cassettes so that by soldering the batteries, we get a parallel connection.

The next step is to solder the batteries together. Many already know that batteries cannot be soldered with a soldering iron, as it is very easy to overheat them and they will fail. Most The best way battery connections are contact welding, if you have one, then you are a very happy person and use it to assemble this homemade product. Well, if you just own a soldering iron, then keep in mind that you should solder the batteries for a short time so that the battery does not have time to warm up, and also use soldering acid for soldering. It is necessary to tin the batteries as in the photo, and then attach the wire by soldering.

For the next step, we will need a Power Banka control board, this fee includes many functions that allows you to make the design as compact as possible. We solder our battery assembly to the control board. Not forgetting the polarity, there are “+” and “-” markings on the board, so you won’t get confused.

Let's make a body. For the body, we will need a wooden MDF panel, but you can use any suitable flat material that you can work with. We cut out a panel of a suitable size and, attaching the control board, circle it along the contour.

Cut out a window for the display. The MTF panel is quite soft and in order to cut a window for the display, we need a clerical knife. We simply draw several times with a knife along the marked contour, using force.

Using hot glue, glue the battery assembly and the control board to the MTF panel.

From the same MTF panel, two identical rectangles should be cut, the length of which will be equal to the length of the main part of the case, and the width should be such that the battery fits. And two more identical rectangles of the same width, but the length should be equal to the width of the body. After we cut out the blanks, we glue two of them, those that are shown in the photo.

Seeing that the LED from the control board interferes a little, the author decided to make holes so that its indication could be seen and the LED did not rest. And also glued to the body.

Then, on the other panel, we also mark the holes for USB and Power Bank charging. And also glue it to the body with super glue.

On one of the side parts we cut and drill holes for the switch and the off button. We need a switch to turn solar charging on and off.

Next, we need a solar battery, which should be connected to the control board. Solder should be in the places indicated in the photo, and through the switch.

Since our solar battery is smaller than the Power Bank case and it will not be enough to use the wall. For the last wall of the case, we will cut out a small rectangle from the MTF panel, and glue it with super glue to the indicated place as in the photo.

And glue the solar panel itself to the case and finish assembling the case.

There are many ways to secure your mobile device external source of energy. Flagship smartphones today equipped with branded wireless modules for charging. Someone does it easier and purchases additional batteries for their phone or tablet. Others enjoy external batteries on solar batteries.

All these methods are good, but sometimes they cost a lot. Therefore, we will use a life hack and create our own power bank from improvised means:

• conventional batteries;
• smart flashlight;
• old batteries.

Which one to choose, you decide for yourself, but they are all very simple and reliable in their design.

First way

For assembly you will need:

• 4 AA batteries, 1.5 V each.
• Plates.
• Wire.
• USB connector.
• Empty matchboxes.
• Glue.
• A suitable size container for the entire structure.

We take empty boxes and bend them on one side so that a pair of batteries fits in each.

At the bottom of the boxes we install metal plates, thereby connecting the "+" and "-" batteries.

We connect the "+" and "-" of the two pairs to each other in a serial circuit, connect the wire of the USB connector to the free contacts.

The whole structure for convenience can be packed in a suitable container. The device is ready for use.

Important so that the output parameters correspond to the current consumed by your device (at least 1A in total, otherwise the device will charge for a long time).

Second way

We disassemble the flashlight and to the terminals, observing the polarity, we connect the voltage converter to 5 V. It can be removed from the old mains charger with a micro USB connector. Solder the wires. We tie the structure with electrical tape for strength and compactness.

As a result, we get 2 in 1: both a flashlight and external charging for a smartphone.

Third way

This design is being prepared on the basis of old batteries from all kinds of household appliances. The total voltage must not exceed 5V. We only solder the side contacts to each other, since the central ones, as a rule, are responsible for exchanging information with the controllers. Then, to the resulting powerful monolithic battery, we solder, as in the case of a flashlight, a current power converter.

It is advisable to pack the entire structure in a compact container - a cream box or a soap dish.

Thus, you have made another external charger for your device.