Homemade power bank charge indicator. How to make a camping Power Bank with your own hands

External batteries for mobile devices are needed by almost every user, because they run out quite quickly, especially when the processor is under high load.

Advantages

• Relatively low price - high-capacity batteries are expensive, while cheap analogues quickly fail, therefore, if the necessary components for assembly are at hand, then it is profitable to assemble such a device;
• In the event of a malfunction homemade battery easier to fix, since it will have a removable case, and you will understand the circuit design;
• The ability to make the device of the desired capacity is large enough;
• You can make a replaceable body of the device so that in case of damage you do not have to change the entire power bank;
• From an environmental point of view, recycling (for example, from batteries with a broken charge controller) is also beneficial;
• original or strange appearance devices for some users may also be attractive.

• A lot of time is spent on the manufacture of the battery;
• You need to have some initial skills to assemble it;
• Poor appearance of the device;
• Not all materials for the manufacture of such a device may be at hand;
• In most cases, the service life of such a device is lower than that of the factory counterpart;
• In the most simple options home-made equipment lacks charge indicators, on and off buttons, which is not convenient (if they are present, then self-assembly will become excessively long, complicated and expensive);
• Theoretically, such a device can harm the battery. mobile device and even cause it to burn out (but there is such a risk when using any power bank made by a brand different from the brand of your device);
• When collecting such a battery, in any case, a charge controller is also needed, and taking into account the cost of their purchase, the final price of the device will not be so low.

Attention! Do not undertake self-assembly if you do not have enough skills for this. In the event of an error in the assembly of circuits, the device can cause significant harm.

materials

Make your own external battery can be from charge carriers of any type.

The most common materials are:

• finger batteries;
• Batteries from old phones with sufficient capacity;
• Batteries from old laptop batteries.

In any case, regardless of the media you choose, you will need a charge controller to which the USB cable will be connected.

Naturally, it must be taken into account that all media must be in good condition.

From phone batteries

This is a fairly simple way. The device turns out to be relatively compact and convenient, as well as capacious.

To make it, you will need 6 batteries - accordingly, the larger their capacity, the greater the total capacity of the power bank.

You can make it like this:

• Put three batteries on top of each other, orienting the contacts in one direction, and wind the stack with tape - neatly and tightly enough;
• Repeat the same with the other three batteries;
• Make sure that all terminals are directed in the same direction and are not covered anywhere with adhesive tape;
• Now solder the extreme terminals in pairs in both piles - pluses with pluses and minuses with minuses, respectively (it will be easier to do this if the batteries were originally about the same size);
• The middle terminals do not need to be touched;
• Now prepare the case - it can be any type of plastic box;
• Mark the place in the box where the future charge controller will be located, and cut out the area for USB;
• Attach both stacks of batteries to the controller;
• Fasten the device in the case in the appropriate place and close the case.

Leave the plastic box detachable for maintenance and cleaning, as dust can enter through the cut out hole.

Usually, such a device is enough for 4-5 charge cycles of an average, not very powerful, smartphone.

Remember that only hot melt adhesive should be used for any work to fix the equipment in the case.

From finger batteries

This method is also simple, but it is rather unreliable.

Such batteries are heavy and do not have sufficient capacity.

But they are cheap and easy to assemble.

• Take two matchboxes, cut off their top sides;
• Glue the boxes base to each other;
• Place two batteries in each box, orienting them in one direction with the poles;
• With the help of clips from the stapler, create contacts between the batteries from two boxes - minus with minus, plus with plus, on both sides;
• Secure the brackets with wire (the main thing is not to use tape, as it can sometimes isolate the contacts);
• Place the entire device in a box where it will be compactly fixed and the contacts will not be damaged;
• Find a case in which to place the entire battery - mark the place in it where the USB output will be located;
• Solder a short wire to the USB output;
• Fix the outlet in the device case;
• Solder the battery to the USB output;
• Fix the entire structure in the housing with hot glue.

The device is ready. This is a power bank small capacity but it is compact, light weight and easy to carry.

From car charger

In this way, quite powerful high-capacity batteries are obtained. They are suitable for recharging tablets, laptops and other energy-intensive devices.

18650 batteries are most suitable for this purpose.

You can get them from laptop batteries, but the elements must be working.

Working batteries are sold very cheaply on various sites, but with burnt controllers - just right for this product:

• Remove the batteries from the batteries - you only need 6 pieces;
• Prepare the case of the future battery - cut or drill holes in it for the USB input and for the switch (such charging makes it possible to make a switch);
• Solder together two blocks of 4 batteries according to the diagram in the picture;

The capacity of such a device should be enough for about 2-3 full charge cycles of a sufficiently powerful device with high power consumption. In order to start charging, connect and then press the enable relay. When turning off, first drag the relay to the off position, and then unplug the device.

From a flashlight

A standard flashlight with LED can also be turned into power bank.

To do this, you will need the flashlight itself with a 3.7 volt battery, a charge controller, as in the previous examples, a voltage converter with a USB output.

Such a converter is needed only in this method self-assembly device, since the output of 3.7 volts needs to be converted to 5 volts necessary for charging the phone.

• Disassemble the flashlight and find the resistor to which the LED is attached;
• Unfasten the LED;
• Remove the metal plug with which the flashlight was previously charged;

• In its place, install a current converter with a USB output;
• Now solder both poles of the flashlight battery to the controller - both plus and minus to the appropriate places;
• Take a close look at the controller - it has two contacts - OUT + and OUT-;
• Attach a 5 volt converter to them;
• Release one of the switch contacts;
• Solder the converter to the released contact;
• Use a voltmeter to check if the converter is working;
• If it does not work, then resolder to another pin at this stage;
• Check again - everything should work now;
• Now attach the controller and converter to the flashlight body with hot glue;

But even if they are, you need to find all the components of the device, and if batteries from non-working batteries are easy enough to find, then in most cases you will have to buy a charge.

Given the cost of the controller, USB output and, in some cases, the converter, the economic feasibility of self-assembly seems to be minimal.

But if for some reason such components are at hand, then an additional power bank will not be superfluous.

In everyday life, people often use gadgets (smartphones, tablets, etc.), but going somewhere on the road, we constantly need to charge our phone. This problem will be solved by the Power Bank, which can be made in an hour and a half from the available components.

Materials and tools

Tools:

• Soldering iron (solder, flux).
• Wire cutters.
• Stationery knife.
• Glue.
• Soda.

Materials:

• Frame.
• - 2 pcs.
• USB (mother).
• Switch.
• LED and 100 ohm resistor.

Power bank scheme

I collected this Power Bank according to this scheme.

Making a Power Bank with your own hands

First of all, I started making a battery for the future Power Bank, I made contacts from a copper bus. Battery capacity is about 2000 mAh.

Next, I connected two batteries in parallel with each other using segments from the bus, but keep in mind that it is not advisable to solder the batteries, you need to do this with a powerful soldering iron and very quickly so that they do not have time to heat up.

When connecting the batteries, the voltage on both should be the same (4.2 volts), but it is best to charge them separately, and then solder them into the battery.

As a case, I used an old doorbell, from which I first pulled out all the electronics, and I removed unnecessary protruding elements with the help of wire cutters.

Next, I installed the USB in place where the bell switch was previously built in, using super glue and baking soda.

By the same method, I installed a switch next to the USB.

I soldered the minus of the battery to the minus from the converter, it is desirable to take thick wires, because the currents here will be from 1 to 3 amperes, depending on what you will be charging.

In the same way, I soldered the positive wire, connected the switch to the gap.

Next, I set the converter to the desired voltage, this voltage should fluctuate between 5.2 and 5.5 volts. Batteries must be fully charged when setting up.

Using a soldering iron, I made a hole for the charge controller.

I glued the controller itself to super glue and soda, why soda, but because glue and soda form a durable polymer.

I will install the batteries with double-sided tape.

I installed the converter next to the controller, and also glued it on glue and soda.

Then I soldered the wires to the output of the converter, and soldered them to the USB on the extreme contacts, the contacts that are in the middle I closed them together, this is necessary so that the phone does not mistake the Power Bank for a computer and does not charge with a current of 500 mAh.

I soldered the plus wire from the controller to one switch contact, and the negative wire to the converter input.

From a piece of plastic, I cut out a diffuser for the LED and installed it between the switch and usb.

Since portable electronic devices, such as tablets, netbooks, cameras or smartphones, then there was a big problem with ensuring the recharging of these devices, since often some people during the day do not have the opportunity to power the battery of their equipment from electrical network. This task was successfully solved thanks to external batteries or, in other words, power banks, thanks to which it became possible to recharge your device while being outdoors, in nature or in transport.

Of course, power banks are now mostly inexpensive, but if you want, you can easily create it yourself. Its manufacturing process provided you have the necessary components, it will not take much time. Two or three hours will be enough. The main thing is that you have the desire to go through all the required steps, and, in addition, your ability to solder and understand electrical circuits will be useful.

If you are interested in how quickly and without any hassle to collect a power bank you can watch this video online.

Do-it-yourself schemes for the development and creation of power banks

From mobile phone batteries

One of the most simple ways . You will need to follow the following steps for this purpose:

Power bank from a lantern

In order to make a power bank with your own hands using a flashlight, you need to prepare the following items: the flashlight itself with a battery for three point seven volts; charge fee; a voltage converter that is capable of converting a flashlight voltage of three point seven volts into five volts, always with a USB output.

Procedure for creating homemade power bank is the following:

Power bank on finger batteries

In order to make such an external battery, take two matchboxes, bend one of the walls at each of them, and glue these boxes to each other. Then put two batteries in each of the boxes. Using staples, ensure a reliable connection of the boxes to each other and additionally wrap them with wire. Choose a case for your external battery. It will be very good if the distance between the matchboxes and the case is minimal or completely absent.

After that, find a large plastic jar that can fit your power bank, and cut a hole in its lid where you attach USB connector. Solder a wire to this connector and connect it to your power bank. Put your external battery in a jar and close it with a lid. Now the manufacture of the power bank is finished, and you can use it to meet your own needs.

Frequent trips on business trips and household chores led to the idea of ​​​​buying a reliable charger of the type for an Android mobile phone that is always in need of power. Since the delivery time from transcendental wishes for the best, but it was necessary yesterday that the option "self-pan-made from ready-made" was chosen. In time, an article turned up on the now ubiquitous LiPo / LiIon batteries.

A trip to the store brought another joy, a ready-made 5 volt DC-DC converter charging module. They have already begun to be imported in connection with the demand of our friend, a radio amateur.

The scheme of this converter, as well as the description, can be freely found on the Internet.

• KEY FEATURES
• Conversion Type DC to DC
• Input Voltage 2.3 to 4.8V
• Output Voltage 5 V
• output current 1 A
• Efficiency 87%
• Topology Boost

Well, everything is purchased and checked, Hurray! Works. LiIon picked from a dead laptop battery bought a few months ago on one of the sites where people sell all sorts of unnecessary stuff. Six batteries were connected in parallel, as a result, although not new batteries, the power of the Power bank was raised.

The case is small, alas, you can’t pick up a case in our store, we will cut plexiglass, we have dichloroethane at home in stocks. I cut and glued it in half an hour, so there will be no pictures, but please, the finished device.

After sea trials, I came to the conclusion that without a battery controller, banks can be killed. There is also a ready-made solution, a battery from a mobile phone, in my Samsung case. We disassemble and take out the controller, which for our purposes is just what the doctor ordered.

The controller installed between the DC / DC converter and the battery, the Powerbank test showed that this circuit works and the full charge of the power bank is enough to charge the gluttonous Android four times.

When the charge on the batteries drops to 3.2 volts, the controller turns off the converter, the controller does not take part in charging, but the board based on the microcircuit charges it TP4056 up to 4.2 volts. I threw a capacitor on the stabilizer board for the sake of stable operation of the controller with the converter. Sincerely, UR5RNP.

The device, in itself, is quite useful, when it’s not quite Chinese, and it costs 2 times more. This one was ordered just for experiments and improvements. About a month later, the device crawled to the local post office, and then fell into our hands:

Such is the unremarkable black glossy case. At the top is some kind of button and what should be a level indicator. On one end of the case there is a miniUSB connector for charging the device, and on the other - two USB connectors for connecting mobile equipment. The Chinese promise them 5V with currents of 1A and 2.1A.

A few days later, he was subjected to ruthless disassembly, for this, in principle, he was ordered. It turned out to be quite easy to disassemble this miracle of technology, the Chinese tightly sealed the case around the perimeter. And now, after half an hour of torment, the following picture appeared before our eyes:

Inside there were 4 18650 batteries, the same as in laptop batteries (just such batteries were prepared before ordering the device), while only two of them turned out to be connected. As it turned out later, the unconnected batteries showed no signs of life and had already begun to rust under the plastic wrap. In this connection, they were immediately sent to the trash.

Between the batteries, the control board was comfortably attached, which contained:

• boost STEP-UP converter on some unknown chip with a rating 8628 (d Atashit on it could not be found);
• voltage level control circuit to prevent overdischarge of batteries and in combination Charger on two DW01 chips (control chip) and 8205A (two MOSFET transistors);
• a pair of transistors to turn on the "charge level indicator";
• "charge level indicator", which actually turned out to be four LEDs connected in parallel.

We did not touch the converter circuit, because enough to charge your phone. In addition, there is overcurrent protection. Yes, the USB connectors marked 5V 1A and 5V 2.1A are connected in parallel. But the control / charging circuit was taken up closely. It turned out to be standard, these are put on ordinary lithium batteries. It looks like this:

MOSFET transistors M1 and M2 are just the 8205A chip. From further use of it as a charger had to be abandoned. Firstly, when 4 batteries were connected, it heated up quite strongly, and secondly, about 5V was supplied to the batteries themselves. Yes, and charge 4 batteries connected in parallel, and even without temperature control, not the most best idea. Therefore, the search for an alternative solution began. The choice fell on microchips. Her characteristics are:

• supply voltage from 4 to 8V. (typical 5V.);
• configurable charge current. maximum current 1A;
• battery charging voltage level 4.2V;
• temperature control with a thermistor negative TCR;
• minimum external components.

Scheme of inclusion infrom this (taken from the datasheet):

It turns out a very convenient thing, you only need to set the charging current level with the Rprog resistor and apply power, and the microcircuit will take care of the rest. The Chinese, by the way, produce ready-made modules for charging lithium batteries, but there is no provision for connecting a thermistor, which is a huge minus.

The chips themselves were ordered from the same ebay, in the amount of 5 pieces. At first it was supposed to make a separate channel for each battery, but due to space limitations, I had to limit myself to two channels and connect the batteries in pairs (especially in a laptop battery it was done in exactly the same way). As a result, this scheme was born:

As you can see, in addition to the charger circuit, two indicator LEDs were added to the device. HL1 lights up when the charging process is completed by both microcircuits, i.e. as long as one of them continues charging and the end signal is not issued, the LED will not light. The HL2 LED lights up if one of the microcircuits stops signaling normal operation (i.e., overheating, breakage, dead battery, etc.). In the meantime, both microcircuits say that everything is fine, the LED is off. Pairs of batteries are connected through diodes to exclude the influence of microcircuits on each other during operation. The diode should be chosen with the lowest junction resistance, otherwise the output voltage will be noticeably lower than the battery voltage and the control circuit will turn off the converter too early. I took the S30SC4M diode assembly from computer block power supply, the voltage drop was 0.25V. Quite a good result, although not ideal. The charge current is adjusted based on the parameters of the charger. As it turned out, none of the ones we have gives a current of more than 1A. Therefore, the charging current for each pair of batteries is limited to 0.5A. It is just comfortable for microcircuits to work, but with a higher current, you will have to think about cooling the microcircuits. The thermistors were soldered from a laptop battery. At room temperature, they had a resistance in the region of 8K. The microcircuit considers the situation an emergency if the voltage at the first output becomes less than 45% of the supply (2.25V) or above 80% of the supply (4V.). Based on this, the values ​​​​of the resistive divider at pin 1 of the microcircuits were selected.As a result, at room temperature, about 3V comes to the TEMP pin. at room temperature.

The whole thing was assembled on this board:

It can not be called a masterpiece, but it was, frankly, too lazy to redo it. Moreover, this board works fine, there are no breaks or short circuits on it, and a couple of blurry tracks have not bothered anyone yet. The "burdocks" on both sides of the board are thermistors and just fit conveniently under the batteries. Yes, 0.5 ohm resistors could not be found, so I soldered two 1 ohm resistors. parallel to the "sandwich".

Now the most interesting moment has come, the connection of two boards - Chinese and ours. Before starting the merging procedure, some modifications must be made to what was originally installed in the device. Firstly, for some incomprehensible reason, the Chinese made it so that when submitting external power supply the converter was launched on the board and threshed into an empty one. Secondly, the LEDs of the "level indicator" began to glow, which interferes quite strongly at night. So, we take the board and begin to solder unnecessary elements from it:

Namely, a diode (so that there is no unnecessary voltage drop, and it did not warm up weakly, later a resistor with a rating of R470 was removed), and a 100K resistor. (Just through it, the fact of supplying the supply voltage was controlled). At the same time, we change the resistors in the DW01 harness in accordance with the datasheet - 470 Ohm to 100 Ohm, and 2K to 1K. (they are not changed in the photo). On the back of the board, we also make some changes:

Separate input and output land. Now the control of the voltage supply to the converter is completely dependent on the DW01 chip. and solder the wires:

Left wire +, right wire -. Accordingly, later, after excluding the R470 resistor, the positive wire is soldered to the pad near the miniUSB connector. The resistor itself performed a purely protective function, but since. we have a separate 0.5 ohm resistor on each chip, this one is superfluous.

Later it turned out that it was necessary to make one more revision of the board:

I had to connect the button directly to the minus of the batteries. This is due to the fact that the circuit has overcurrent protection (as mentioned above). It is all built into the same DW01 chip and with two dead batteries it worked fine (when the load increased, the current on the batteries simply sagged), but miracles began with four. It turned out that if you connect two phones for charging at once, the control circuit immediately disconnects the batteries from the converter. But he does not want to turn it back into any. It helped either reconnecting the batteries, or a short-term supply of minus power, bypassing the control circuit. Naturally, the second method is much simpler and more convenient. Therefore, the button was connected directly to the minus of the batteries, the 1A transistor was removed from the reverse side (connected just parallel to the button, it launched the "level indicator" when external power was connected), which can be seen just below the throttle, and a series-connected diode was soldered in its place and 470 ohm resistor. We solder the diode cathode to the collector pad (bottom in the photo), and the resistor to the emitter pad (left in the photo). The junction of the resistor and the diode very conveniently fell on the base site, which, after removing the 100K resistor, remained absolutely free. A resistor and a diode are needed to protect the circuit (maybe we have a short circuit at the output, but we directly feed the minus). Now, after the protection is triggered, it is enough to turn off the load and press the button.

Now everything is ready for the reunion. In our board, the pads are displayed exactly opposite the pads on the Chinese board. Batteries were previously connected to these sites. I just took and drilled holes in them. Then I soldered two thick leads left after soldering to my board diode bridge, and then soldered them to the main board, soldered the LEDs, wires from the batteries and power (the minus of the batteries is connected to the same place where it was originally, near USB connectors and minus the power supply from the miniUSB connector goes there too). I think that in graphical form It will be clearer, because it is better to see once than ...

In reality, it all looks like this:

In this form, the whole thing was checked for two days, and then it was packed back into the case:

Holes were drilled for the LEDs near the miniUSB connector. The left LED indicates the end of charging, and the right one indicates an accident. additional fee became perfect, as if the Chinese had left a place for her

We connect the charger, but not what came in the kit, but a normal one, honestly giving out 1A. 5V. at the exit. Waiting a while and...

Charging completed, you can use. A full charge is enough for 3-4 full charges of the phone. Despite the fact that at that time they use this very phone and the batteries were not installed new. The goal is achieved, the output is a full-fledged portable charger.

List of radio elements

Designation	Type of	Denomination	Quantity	Note	Score	My notepad
U1, U2	charge controller	TP4056	2			To notepad
VT1	bipolar transistor	BC857	1			To notepad
VT2	bipolar transistor	BC847	1			To notepad
	Schottky diode	S30SC4M	1			To notepad
C1, C2, C3, C4	Capacitor	10uF	3			To notepad
R1, R11	Resistor	0.5 ohm	3			To notepad
R2, R7, R10, R16	Resistor	4.7 kOhm	4			To notepad
R3, R5	Resistor