How to make a portable battery. Homemade power bank for charging a smartphone from Krona. Power bank from old phone batteries

a. A smartphone is a device that has become an indispensable device for all people to communicate. They are used to access the Internet and often for a long time. But smartphones have one drawback - it's battery life. In the best case, the battery will work without recharging for one day, and if you actively use it, then several hours. This article and the accompanying video show you how to make a powerful homemade Powerbank that can even charge simultaneously for a smartphone or tablet, or a combination of the two.

You can buy a baby monitor, which is described at the beginning of the video, and all the components of the power bank in this Chinese store. How to receive a cashback (refund) in the amount of 7% of the price of all purchases is on our website. Download schematic, board and other project files.

In order to improve the performance of mobile phone batteries, portable chargers were ordered, which are commonly called poverbank. But in a single form, such a device is not even half capable of charging the phone's battery. And even three such devices do not give a way out of the situation. Buying a powerful power bank is quite expensive. A normal powerbank, say, with a capacity of 10,000 milliamps costs 25-30 dollars. Given this and the long waiting time for the package, it's easier to make your own version.

Description of the power bank scheme

The powerbank circuit consists of three main parts. This is a lithium battery charge controller with auto-shutdown function when fully charged; battery compartment with 18650 lithium-ion batteries connected in parallel; a 5-10 amp power switch from a computer power supply; boost converter to increase the voltage from the battery to the desired values ​​of 5 volts, which are needed to charge a phone or tablet; USB connector to which the charging device is connected.

In addition to simplicity and low cost, the presented circuit has a high output current, which can reach up to 4 amperes and depends on the rating of components such as a field effect transistor, an output Schottky diode and an inductance. Chinese counterparts are capable of providing an output current of not more than 2.1 amperes. This is enough to charge a couple of smartphones at the same time, and our power bank can handle 4-5 smartphones.

Consider the individual components of the structure. As a power source, 5 parallel-connected 18650 batteries from a laptop. The capacity of each battery is 2600 milliamps per hour. An adapter or inverter case is used, but another suitable case can be used. We will use a charge board purchased as a charge controller. The charge current is about 1 ampere. An inverter that will increase the voltage from the battery to the required 5 volts can also be taken ready-made. It is very cheap. Maximum output current up to 2 amps.

Circuit Assembly

At the first stage, we fix the batteries, fasten them together with a glue gun. Next, you need to connect a controller to the battery to check how the charging process is going. You also need to find out the battery charge time and understand if the auto-shutdown works when fully charged. Everything is signed in detail on the board.

You can charge from any USB port. The indicator should show that charging is in progress. After 5 hours, the second indicator lights up, which means that the charging process is completed. If a metal case is used, additionally insulate the batteries with a wide adhesive tape.

One of the main components of the circuit is a step-up dc-dc converter, an inverter - a voltage converter. It is designed to raise the voltage from the batteries up to 5 volts, needed to charge the phone. The voltage of one battery is 3.7 volts. Here they are connected in parallel, so an inverter is needed.

The system is built on a 555 timer - a field-effect transistor and output voltage stabilization, which is set using a zener diode vd2. A zener diode may have to be selected. Any low power zener diode will do. 0.25 or even 0.125 watt resistors. Choke L1 can be removed from the computer power supply. The diameter of the wire is at least 0.8, it is best to make 1 millimeter. The number of turns is 10-15.

A frequency-setting node is assembled in the circuit, which sets the operating frequency of the timer. The latter is connected as a rectangular pulse generator. With this selection of components, the operating frequency of the timer is about 48-50 kHz. Gate limiting resistor R3 for a 4.7 ohm FET. Resistance can be from 1 to 10 ohms. You can replace this resistor with a jumper. Field effect transistor of any average power with a current of 7 amperes. Field workers from motherboards will do. A small reverse conduction transistor vt1. A kt315 or other low power reverse conduction transistor will do. Rectifier diode - it is desirable to use a Schottky diode with a minimum voltage drop across the junction. Two containers stand as a power filter.

This inverter is pulsed, it provides high efficiency, high stabilization of the output voltage, does not heat up during operation. Therefore, power components do not need to be installed on the heat sink. If there are difficulties with Schottky diodes, then you can use the diodes that are in computer power supplies. Dual to-220 diodes are found in them.

In the photo below, the inverter is assembled.

You can make a printed circuit board. There is a link in the description.

5 volt inverter test

We check the inverter for operability. The smartphone is charging, as you can see, the charging process is in progress. The output voltage is kept at 5.3 volts, which is fully compliant. The inverter does not heat up.

Final body assembly

From a piece of plastic, we need to cut the side walls. The charge controller has two LED indicators that show the percentage of charge. They need to be replaced with brighter ones and brought to the front panel. Two holes for micro USB connectors are cut out in the side wall, that is, two devices can be charged at the same time. There are also holes for LEDs. A hole for the controller, that is, for charging the built-in batteries. A small hole for the power switch will also be made.

All connectors, LEDs and the switch are fixed with a glue gun. It remains to pack everything into the case.

A USB tester is connected to the output of the device. It can be seen that a voltage of 5 volts is firmly held at the output. Let's connect mobile phones and try to charge them from a homemade Power bank. Two smartphones will be charged at once. The charge current jumps to 1.2 Amperes, the voltage is also normal. The charging process is running successfully. The inverter is working flawlessly. It turned out compact and, most importantly, stable. The circuit is easy to assemble, all familiar components are used.

It's no secret that the tablet's battery is very energy-intensive. Otherwise, how to “feed” such a giant that has a large screen, powerful speakers and no less powerful Wi-Fi, Bluetooth and GPS modules ... It’s very unpleasant that these devices break down much more often and faster than others that are not so useful and interesting gadgets. A fairly common cause of failure is a crushed screen. Due to its considerable size, it is he, as the most fragile part in the entire structure, that is subject to external mechanical stress. A simple fall from the hands of a clumsy owner is enough ... and whoever manages to sit on it. It was such a crushed tablet that they brought me recently, for spare parts.

The device, according to its owners, was not yet a month old. The order and purchase of a new screen, as well as the payment for the work of the master for replacing the screen, almost doubled the cost of the tablet itself, so its owners wisely abandoned this idea. However, even from a broken tablet, you can extract a lot of useful and necessary things, and one of them is batteries. It is from these, almost new batteries, that I propose to assemble an external charger. Most tablets of this type usually have paired lithium batteries. Each of them has 3.7 volts output and 7000 mA * h. By connecting these two batteries in parallel (plus to plus, and minus to minus), we will get the same 3.7 volts at the output, but the capacity of such a double battery doubles - up to 14000 mA * h. These are very good indicators for an average external charger. 3-4 times you can safely charge even the most modern smartphone. The most problematic thing in this venture was to work the hull. Well, I had to order online. I ordered not the cheapest, but not very expensive either - medium.

The parcel arrived pretty quickly.

It will take

• Tablet batteries.
• Soldering iron, tin and flux.
• Double tape.
• Thin wires (preferably black and red).
• Scissors.
• Second glue and soda.
• A sheet of plastic (1.5-2 mm thick).
• Burner.
• Colored adhesive film (for decorative cladding).
• Flat screwdriver.
• Ruler and marker.
• Files.

Power bank manufacturing

So, first you need to remove the batteries from the broken device. Using a flat screwdriver, remove the cover from the tablet. We disconnect the plug of the charge controller, to which the batteries are soldered, from the tablet board and remove the batteries together with the controller. We unsolder the batteries from the controller and remove the controller - maybe it will come in handy in the future.

The main and, in my opinion, rather tedious work is to design the case. Let's start with him. Having picked up a plastic of suitable thickness, I got down to business.

We measure the length and width of the battery, not forgetting about the additional space for the new charge controller and, using a ruler and a marker, transfer the parameters to a plastic sheet.

The thickness of the future device is determined based on the thickness of the most voluminous part of all components.

Next, we cut out the blanks with a hot burner sting.

It was possible to cut all this strictly along the drawn lines and then just remove the melted edges with a file, but I decided to save time and cut it off with small margins so as not to scuff the file later. I just took powerful scissors and trimmed the plastic blanks along the lines ... So, the body blanks are ready.

Now on one of the front ends we mark with a marker where the input and output connectors of the device will be located. Again, with a burner, we cut out approximate holes, and finish them with a thin needle file.

Now let's prepare the battery. Namely, we evenly glue one to the second, using double adhesive tape, solder the contacts in parallel - plus to plus, minus to minus (here you need to be extremely careful!) And solder the wires to the soldered contacts. Red is positive, black is negative. This is to avoid confusion.

Now, using instant glue and soda, we glue the charge controller to the corresponding holes in the pre-prepared end wall of the case.

Next, let's take a look at the indicator. This controller does not have an on / off button, and there is no display showing the charge level. Instead, there are two microdiodes - blue and red. Red blinks when the device itself is charging, and glows solid when charging is complete. Blue, on the other hand, glows steadily when the device is charging a gadget, and goes out when the charging gadget is fully charged. In order to bring this indication out, through a deaf and opaque plastic, I made a hole in the top cover of the case, at the approximate location of the indicators. Then I glued a light diffuser from the camera flash into this hole (picked out from the same tablet). It turned out to be a very good and accurate indicator.

Now we glue the end with the controller glued into it to the bottom cover of the case and stick double tape on the inside (on the bottom).

We put the batteries on the adhesive tape and solder the positive and negative wires to the corresponding terminals of the controller (terminals B+ and B-). It is important not to confuse the polarity, otherwise the controller will burn out instantly - there was already a bitter experience ...

Next, we collect the rest of the body together, gluing everything with a second glue.

There is very little left; grind off with a file all protruding and sharp corners from the ends, process it with non-rough sandpaper, and paste over the product with an adhesive film of any color you like. For example, I pasted it with black matte.

In a Power bank store, with such a charge capacity, it is very expensive, but in our case, it cost us the cost of a charge controller ($ 2) and a couple of hours of work ... In addition, it turned out to be no larger and thicker than a charger from store, factory assembled - the size of a palm, but very energy-intensive.

If you connect a USB hub to it, it can really help you and a few other people during a long trip, outdoor recreation, or when the power goes out in time, for example, for repairs.

Everyone brains, Hello! I think you all belong to the part of the population of the planet who use smartphones, and I think that over the past couple of years you have changed them several times to more advanced ones. All "legacy" smartphones have lithium-ion batteries, which are not possible to use in new models, and thus you end up with good, but useless batteries ... But is it?

Personally, I have accumulated three phone batteries (and I did not change phones because of battery failure), they did not heat up or swell, and they can be used to power some gadgets. The capacity of an average battery after 2 years of use is about 80% of the original, this is exactly the period during which I usually buy a new one brainsmartphone. And if you think about the effort to obtain the raw materials, the production of the batteries themselves and the cost of transportation ...

All things considered, it would be a real shame to let them "die" slowly or just throw them away. In this brainarticle and roller i'll tell you how do it yourself do homemade, which allows you to "give new life" to batteries from old phones, that is, to make an external battery for gadgets, aka POWERBANK.

Step 1: Materials

Well, let's start with what you need to create your own external battery. Of the materials needed:

• lithium ion battery,
• charging and protection board for lithium-ion batteries, rated at 5V, maximum input current 1A (the smaller, the longer the “second life” of the battery will be),
• DC boost converter with 5V output and max. 600MA
  wires,
• multiple pin connectors
• office clip,
  a piece of acrylic
• screws,
• and switch.

You will also need:

• a pair of pliers
• stripper,
• soldering iron,
• and a glue gun
• as well as a drill and a grinder.

Step 2: How do the boards work?

First, let's get acquainted with the charging and protection board for lithium-ion batteries. Its three important functions are charging, over-current protection and over-voltage protection.

Lithium-ion batteries are charged according to a certain pattern - when they are almost fully charged, their current consumption is reduced. brain payment recognizes this and as soon as the battery voltage reaches 4.2V, it stops charging. The output of the board has a protection circuit to prevent over-current and over-voltage. Such protection is already built into modern telephone batteries, but in this homemade this board will allow the use of unprotected batteries found in older laptops. The charging current of the board can be adjusted with a resistor and should be within 30-50% of the nominal battery capacity.

The DC converter converts the battery's DC voltage into a square wave and passes it through a small coil. Due to induction processes, a higher voltage is formed, which is converted back to constant and can be used to power gadgets designed for 5V.

Now, more or less knowing what we are dealing with, we can proceed to the actual assembly brain crafts.

Step 3: Design

Before proceeding with the creation of the case for homemade, measure the components and make a drawing. So in my brain device the battery will be fastened with a clerical clip, which is screwed to the case, the boards will be located on top of each other, the input / output contacts will be on top at the top of the case, and the contacts going to the batteries will be at the bottom.

Some batteries have a non-standard position of the polarity of the contacts, so this "non-standard" must be taken into account in our device, that is, add pin connectors. To do this, we take a connector with three pins and pull out the middle one, and bend the pins themselves on one side, so that it is more convenient to apply them to the battery contacts. Or take a connector with four pins, the outermost of which are connected to the positive terminal, and the middle ones to the negative terminal, and thereby change the polarity of the contacts simply by connecting the battery to the left or right pair of pins.

Step 4: Building the Case

Now let's start assembling the case. To do this, we take a ruler and mark the lines with a sharp knife, scratching them about 10 times, so that then we do not apply great effort to the workpiece and no longer use the ruler. Having scratched the lines to a sufficient depth, we apply pliers to them and bend the workpiece until it breaks along these lines. "Breaking" in this way all the necessary details braincase, we clean them and adjust them to each other. Then we fix them to a stable surface and use a drill to make holes and slots for screws, a switch, inputs, outputs and pin connectors.

Step 5: Assembling the Circuit

Before starting assembly brain devices first we assemble the electrical circuit, and at the same time we are guided by the presented diagram. The small switch here serves to turn the DC converter on/off.

Step 6: Final Assembly

Using a glue gun, we glue the boards to each other, and then to one of the parts of the case. Next, we glue the entire body, and screw a clerical clip to it.

We connect the battery through the pin connector and try homemade In action. If it does not work, then connect the charging cable.

Step 7: Use!

Well, now your old phone batteries are back in business!

The version of the case I proposed is certainly not ideal, but it will fit to demonstrate the whole concept. I can even bet that you will come up with a much better solution :)

That's all, everyone brain luck!

Situations are different, for what purposes a power bank may be needed. Or another name is an external battery for a smartphone. That is why it was decided to make our own, powerful Power Bank from an old laptop battery, with USB power. Of course, you can buy Chinese, but their 10,000 and 20,000 mA is a big exaggeration! This article will show you how to assemble a device consisting of a Lithium Battery Charger Module, a USB Boost Converter, and a Power Bank Battery Status LED.

Let's start with where to get lithium batteries for a power bank.

It’s better not to buy the batteries themselves (it’s expensive and there are a lot of weak ones), but to use them from an old laptop. Inside this, which is in the photo - 3 packs of two parallel assemblies of lithium 18650 type 2200 mAh, which are connected in series.

In our design, we will use all 3 packages in parallel, having previously checked whether they hold a charge well for a sufficiently long time.

As a last resort, if some banks are already quite weak, put one double package - then the bank will become lighter and smaller, albeit weaker.

You will also need a module for our homemade external battery.

You can take it from an old, or low-capacity power bank.

Now we take a circuit that increases the voltage from the batteries to 5 volts (to power the USB output). This is any boost converter to USB.

Naturally, the circuit diagram will have a small toggle switch to turn on the Power Bank. The toggle switch is needed because the boost converter is always powered by the battery (and draws a small amount of current), even if no device is connected to the USB.

It is better to take a non-metallic case - a suitable plastic box, cable channel, and so on. For this project, a non-standard and environmentally friendly material was used - wood, more precisely fiberboard. Two covers and walls around the perimeter, all connected with screws

In this episode of the “AlexGyver” channel, the master talked about how to make the simplest, most honest and, presumably, the most profitable and cheapest power bank with your own hands. The basis will be prepared by the Chinese module. The cost is 100 rubles. It produces 1.2 amperes of charging current, 10 ampere hours.

It has 2 USB outputs on board. Input for charging, display. There are many different Chinese modules. You can do the one you like best. All of them run on batteries connected in parallel. There are more powerful options. But they will be more difficult to work with, because they do not have an input for a charger and USB. Runs on batteries connected in series.

The battery in our power bank is 18,650 lithium batteries. You can use old laptop batteries. You can go to some service and beg or buy a dead battery from them, but they have a low capacity. So the project will turn out to be very cheap, but not very effective.

The technician will use Sanyo batteries. For maximum capacity, you need to take a green NSR. The price for 1 ampere hour is the same. So we lose nothing and pay purely for the capacity. 3 NSR batteries will give a capacity of exactly 10 amp-hours. Or 12 watt hours, respectively.

As a case, ready for 60 rubles. Three batteries fit into it with almost no gap. Two plastic racks need to be bitten off so that they do not interfere. The essence of the project is as follows. You need to connect the batteries in parallel and connect it to the power bank module. Lithium batteries can be connected in four ways. The best is contact welding. But it is not available to most viewers. The second one is more accessible, but at the same time it is a bit dangerous. This is soldering. Our task is to solder the wire as quickly as possible so that the battery does not have time to heat up. Because it is very harmful to lithium.

Attention! Before assembling the batteries into a battery, be sure to charge them all to the same voltage (or measure and make sure that this is the case). When assembled, they will begin to equalize the voltage, and with a large difference, a strong current will flow.

The second way is quite exotic, but at the same time simple and safe. This is a nickel tape and powerful neodymium magnets 8x1 mm.

The fourth one is even easier. This is the battery compartment. But it's bulky and inexpensive. Will have to work on it a little. To begin with, we remove the side walls right along the steps. They separate from everything else. You also need to cut off the ends. It turns out a very stylish, fashionable and thin holder. But even in this case, it is not very suitable, because you will have to sweat a lot to install the powerbank module. He doesn't fit right in here. Even if it can be placed, but quite back to back. Yes, and the body is deformed - it's ugly. The last two methods allow you to safely insert charged batteries or simply take them out. So it will be cheaper and more convenient to use tape and magnets. This is what we'll do.

First you need to fix the powerbank module in the case. You can see that it is slightly wider than the body. You can take advantage of this. Namely, make two grooves. Insert a board into them. Thus, it will be fixed in all directions. It remains only to make a window for the display at the USB input. It is most convenient to work with a dremel and a cutting disc. But not everyone has such a tool. So let's see a more accessible method. Scalpel, hot knife and file. Very sloppy, but quite effective. The front struts also bit off. The module falls into place and holds up perfectly.

Continuation from the fifth minute on the video clip