How to make a battery at home. Homemade battery from improvised means

In this article, the master DIYer will guide us through all the steps of battery assembly, from material selection to final assembly. RC toys, laptop batteries, medical devices, electric bikes and even electric cars use batteries based on the 18650 cell.

18650 battery (18*65mm) is the size of Li-ion battery. For comparison, conventional AA batteries have a size of 14 * 50 mm. Specifically, the author did this assembly to replace the lead-acid battery in a homemade product he had made earlier.

Video:

Tools and materials:
- ;
- ;
- ;
- ;
-Switch;
-Connector;
- ;
- 3M x 10mm screws;
- Apparatus for spot contact welding;
-3D printer;
- Stripper (tool for removing insulation);
- hair dryer;
-Multimeter;
-Charger for lithium-ion batteries;
-Protective glasses;
- Dielectric gloves;

Some tools can be replaced with more affordable ones.

Step One: Choosing Batteries
The first step is to choose the right batteries. There are different batteries on the market from $ 1 to $ 10. According to the author, the best batteries are from Panasonic, Samsung, Sanyo and LG. At a price they are more expensive than others, but have proven themselves to be of good quality and performance.
The author does not advise buying batteries with the names Ultrafire, Surefire and Trustfire. These are batteries that did not pass the quality control at the factory and were bought at a bargain price and repackaged under a new name. As a rule, such batteries do not have the declared capacity and there is a risk of fire during charge-discharge.
For his homemade craftsman used Panasonic batteries with a capacity of 3400 mAh.

Step Two: Choosing a Nickel Strip
Nickel strips are needed to connect the battery. There are two products on the market: nickel-plated metal and nickel strips. The author advises using nickel strips. They are more expensive, but have low resistance and therefore heat up less, which affects battery life.

Step Three: Spot Welding or Soldering
There are two ways to connect batteries: soldering and spot welding. The best choice is spot welding. When spot welding, the battery does not overheat. But the welding machine (such as the author's) costs approx. 12 tr. in a foreign online store and approx. 20 tr. in the Russian online store. The author himself uses welding, but has prepared several recommendations for soldering.
When soldering, minimize the contact of the soldering iron with the battery. It is better to use a powerful soldering iron (from 80 W) and quickly solder than to heat up the place of the solder.

Step Four: Checking the Batteries
Before connecting the batteries, you need to check each of them separately. The battery voltage should be about the same. New high-quality batteries have a voltage of 3.5 V - 3.7 V. These batteries can be connected, but it is better to equalize the voltage using a charger. For used batteries, the voltage difference will be even greater.

Step Five: Battery Calculation
For the project, the craftsman needs a battery with a voltage of 11.1 V and a capacity of 17000 mAh.
The capacity of the 18650 battery is 3400mAh. With a parallel connection of five batteries, we get a capacity equal to 17000 mAh. Such a compound is designated P, in this case 5P

One battery has a voltage of 3.7 V. To get 11.1 V, you need to connect three batteries in series. Designation S, in this case 3S.

So, to obtain the desired parameters, you need to connect three sections, each consisting of five batteries connected in parallel, in series. 3S5P package.

Step Six: Battery Assembly
To assemble the battery, the master uses special plastic cells. Plastic cells have a number of advantages over connecting them, for example, with a glue gun.
1.Easy assembly of any quantity.
2. There is space between the batteries for ventilation.
3. Vibration and shock resistance.

Collects two cells 3*5. Installs, in a cell, the first pack of 5S batteries with plus up, the next five minus up and the last five batteries again with plus up (see photo).

Sets the second cell on top.

Step Seven: Welding
Cuts four nickel strips, for parallel connection, with a margin of 10 mm. Cuts ten strips for serial connection.

Lays a long strip on the + contacts of the first (it will remain the first when turned over) parallel 5P cell. Welds the strip. Welds the strips with one end to the + third of the cell and the other to - the second. Welds a long strip to the + third of the cell (over the plates). Flips the block. It welds the plates from the reverse side, given that now we connect the third in parallel, and the first and second sections in parallel-series (given that it was turned over).

Step Eight: BMS (Battery Management System)
First, let's understand a little what BMS is.
BMS (Battery Management System) is an electronic board that is placed on the battery in order to control the process of charging / discharging it, monitoring the condition of the battery and its elements, controlling temperature, the number of charge / discharge cycles, and protecting the battery components. The control and balancing system provides individual control of the voltage and resistance of each battery element, distributes currents between the battery components during the charging process, controls the discharge current, determines the loss of capacity due to imbalance, and ensures safe connection / disconnection of the load.

Based on the received data, the BMS performs cell charge balancing, protects the battery from short circuit, overcurrent, overcharge, overdischarge (high and excessively low voltage of each cell), overheating and hypothermia. The functionality of BMS allows not only to improve the operating mode of batteries, but also to maximize their service life.

The important parameters of the board are the number of cells in a row, in this case 3S, and the maximum discharge current, in this case 25 A. For this project, the master used board with the following parameters:
Model : HX-3S-FL25A-A
Overvoltage range: 4.25~4.35V±0.05V
Discharge voltage range: 2.3~3.0V±0.05V
Maximum working current: 0~25A
Operating Temperature: -40℃~+50℃
Solder the board to the ends of the battery according to the diagram.

There are many ideas on the Internet on how to make a battery from improvised means. All of them, in principle, can only be experimental-cognitive in nature. Every lover of homemade products will be interested in making a battery from improvised means.

The simplest battery from soda

Consider how to make a simple battery with your own hands. As a body, we will use a small plastic container with a lid. The main ingredients are baking soda and water.

Water is poured into the container, and 1.5 tsp is added. soda. The resulting solution must be mixed. We make two ends of the cleaned welding electrodes. The length of each of them should not exceed 7 cm.

The ends of each piece must be bent, and two holes must be made in the lid of the container. We insert elements with curved ends into the lid, and cover the container. There are many do-it-yourself battery photos on the Internet, but this is the simplest view.

We take a conventional charger and connect it to the ends of the battery. We do a test charge for 10 minutes, and measure the voltage. It will not exceed 2.5 V, and if you charge the battery for 3 hours, then its power will be enough to operate the LED for no more than 20 minutes. The tightness of the container is not permissible, otherwise the battery will begin to swell.

Battery made of copper and zinc

You can use another scheme for assembling batteries with your own hands. Let's make it from a copper wire (plates), and galvanized plates.

How to assemble

First, prepare the wire, and remove the insulation from it. Twist it into a tight spiral to increase the area. It is necessary to cut several galvanized plates of the same size. Let's prepare several insulated conductors, so that later we can connect the network with them.

Salt water or vinegar is suitable as a conductive liquid solution. You will also need a few disposable cups.

We roll the galvanized plates into a cylinder, and bend the end in order to fix the conductor there. As a cushioning material, we will use a plastic plate that can be cut from a bottle. We place it between the copper and zinc elements.

Next, the process of assembling the battery begins. As a result, we get a serial chain, from several cups. If you fill the elements with saline, then the output can be up to 7 V. Using an acid-type solution, such as vinegar, will give an output of up to 8 V.

The most effective result will come from an alkaline solution. In the field, it is found in ash. Then, the voltage will be equal to 9.6 V. By adding such elements to the serial network, you can get the right voltage level to charge the phone.

Simple gas battery

Consider step-by-step instructions on how to make a gas-type battery with your own hands. The battery is simple in design, so anyone can make it.

Battery design elements

You will need the following components:

Container with a lid;
The rod is coal;
activated carbon;
Saline solution (15%);
Terminal block with stopper;
Activated charcoal bags.

These are the elements from which you can make a simple battery. The prepared container should not let light through, otherwise the battery will quickly run out. An electrolyte solution made from edible salt is poured into it.

Electrodes consisting of carbon rods are also lowered there. Around each electrode is placed activated carbon in a bag.

Each bag must be pressed well against the electrode with threads. There should be enough activated carbon in the bag so that the layer between the electrode and the bag is 1.5 cm.

IMPORTANT! To improve battery performance, 1 g of boric acid is added to 1 liter of electrolyte solution, and no more than 2 g of sugar.

Such a battery is charged up to 12 hours, and 4.5 V DC is allocated to each bank. When gases begin to be intensively released, this means that charging is over.

The cork should not be closed during the charging process, because the gases released can splash out the electrolyte solution from the cans. For quality work, it should be changed once a week.

Caring for a homemade battery

You can give some useful tips for maintaining homemade batteries:

Do not use containers with transparent walls.
Any battery needs distilled water, it is unacceptable to use another type of water, it has an increased mineralization.
To make the correct 15% salt electrolyte solution, you need to dissolve 5 tbsp. salt in 1 liter of water.

The resulting design is quite efficient. The only negative is the strong self-discharge, and high internal resistance.

DIY battery photo

Of course, the battery is easy to buy at any hardware store, electronics store or hypermarket. However, for the sake of interesting experiments and gaining knowledge of the "school of life", it is still worth knowing how to make a battery with your own hands. Moreover, the process of such work is very entertaining and uncomplicated.

Lemon battery: two options

For the first option you will need:

actual lemon;
galvanized nail;
2 small pieces of copper wire;
copper coin;
small light bulb.

The work process is as follows:

Make two cuts on the fruit at some distance from each other.
Place a nail in one notch and a coin in the other.
Connect a piece of wire to both the nail and the coin. The second ends of this makeshift wiring should be in contact with the contacts of the light bulb.
And all - let there be light!

A homemade sour fruit battery can also be made using:

the same lemon;
paper clip;
light bulbs;
2 pieces of insulated copper wire with a diameter of 0.2-0.5 mm and a length of 10 cm.

The algorithm is the following:

Strip 2-3 cm of insulation from the ends of each of the wires.
Attach the exposed part of one wire to the paperclip.
Make two cuts in the lemon 2-3 cm apart - along the width of the paper clip and for the second wiring. Insert these elements into the fruit.
Attach the free ends of the wire to the contact part of the light bulb. If it does not catch fire, then the selected lemon is not powerful enough - connect several fruits in series with each other and repeat the experiment.

Potato battery

Stock up:

two potatoes;
three wires with clamps;
two chrome nails;
two copper nails.

So, how to make a battery from tubers:

Give the symbol for each of the potatoes - "A" and "B".
Insert a chrome-plated carnation into the edges of each of the tubers.
In the opposite edge - a copper nail. In the body of potatoes, nails should not intersect.
Take any device powered by a battery, remove it and leave the compartment open.
The first wire should connect the tuber's copper pin "A" to the positive pole in the battery compartment.
The second wire connects the chrome potato pin "B" to the negative pole.
The last wire connects the chrome nail of tuber "A" to the copper nail of tuber "B".
As soon as you close all the wires in this way, the potato will begin to power the device with energy.

Potatoes in this experiment can be replaced with a banana, avocado, or any of the citrus fruits.

Battery made of foil, cardboard and coins

Before you make a battery, prepare:

copper coins;
vinegar;
salt;
cardboard;
foil;
Scotch;
two pieces of insulated copper wire.

Everything is ready? For business:

First you need to thoroughly clean the coins - for this, pour vinegar into a glass container, add salt there and add money.
As soon as the surfaces of the coins have changed and sparkled, remove them from the container, take one and circle its outline on cardboard 8-10 times.
Cut out cardboard circles along the contour. Then place them in a container of vinegar for a while.
Fold the foil several times so that you end up with 8-10 layers. Circle a coin on it and also cut out round details along the contour.
At this point, start assembling the battery. It is done like this: a copper coin, cardboard, foil. In this order, add up all the components you have in a column. The final layer should be only a coin.
Remove the insulation from the ends of the wires.
Cut off a small strip of adhesive tape, glue one end of the wire on it, put an impromptu battery on top, and the tip of the second wire on it. Fasten the structure securely with adhesive tape.
Connect the second ends of the wire to the "+" and "-" of the device to be energized.

Eternal battery

Prepare:

glass jar;
a silver element - for example a spoon;
food film;
copper wire;
1 teaspoon of baking soda;
4 vials of glycerin;
1 teaspoon 6% apple cider vinegar

Wrap the spoon tightly with cling film, leaving its top and bottom ends slightly bare.
Now it's time to wrap the spoon over the film with copper wire. Remember to leave long ends at the beginning and end for contacts. Make space between turns.
And again a layer of film, and behind it - wires in the same way. There should be at least seven layers of "film-wire" on this impromptu reel. Do not overtighten the layers - the film should wind freely.
In a glass jar, prepare a solution of glycerin, salt, and vinegar.
After the salt has dissolved, the coil can be immersed in the solution. As soon as the liquid becomes cloudy, the "eternal" battery will be ready for use. Its service life directly depends on the silver content in the base element of the coil.

Graphite rod: application

The graphite component from old batteries is not only the basis for a new energy source, but also an element that can be used for electric welding. This is done in a simple way:

Sharpen a graphite rod from an old battery at an angle of 30-40 degrees.
Use an alligator clip with a non-conductive handle to connect it to the "+" and "-" of an AC or DC power source.
Connect "0" and "-" to the cleaned part.
The electrode must be sharpened periodically as it burns out.

How to make a battery at home? You will need improvised materials, a little enthusiasm and perseverance. In exchange, you will receive alternative energy sources.

Initially, lithium-ion batteries were intended for mobile devices, whether it be phones, cameras, camcorders, laptops, but in the last decade, the production of lithium batteries has also been established by most automakers.

Then why assemble it yourself if you can buy a ready-made battery? There are enough reasons:

factory-assembled lithium batteries are prohibitively expensive;
it is very difficult to find a suitable battery for a motorcycle, car;
if the assembled battery fits into the installation place with a margin, then it will have a lower capacity.

With your own hands, you can assemble a battery from individual elements, which will be limited only by energy density and price per watt-hour, depending on the type of elements selected:

NiMH- nickel metal hydride;
Li-ion- lithium ion;
Lipol- lithium polymer;
LiFePO4- lithium iron phosphate;
Lead Acid- lead acid.

Danger of overcharging lithium cells

Lithium cells must be handled with care as they pack a lot of energy into a small area when fully charged. Therefore, protected Li-ion and Li-pol batteries have been on sale for a long time.

Back in 1991, Sony drew attention to the explosiveness of Li-ion cells. Currently, all batteries without exception are wound with a two-layer separator between the plates to eliminate the risk of internal short circuits. All branded batteries are equipped with a field-effect transistor protection board that turns them off in the following cases:

The battery is over-discharged - below 2.5 V.
Overcharged - over 4.2 V.
The charging current is too high - more than 1C (C is the battery capacity in Ah).
Short circuit.
The load current is exceeded - more than 5C.
Wrong polarity when charging.

For additional security, there is a thermal fuse that opens the circuit when the lithium cell overheats above 90 ° C.

How to find a battery with protection?

Lithium batteries are produced in household and technological versions. Batteries for household use have a durable plastic case and built-in electronic protection. Technological elements intended for industrial use are most often produced in unpackaged form and do not have built-in protection.

Protected batteries have the word " protected" in the title, unprotected - " unprotected».
Batteries with protection are 2–3 mm longer than usual ones due to the board, which is installed on the end near the negative pole.
The price of batteries with protection with the same capacity is always higher, because the board with electronic components also costs money.

The positive pole of the battery must be connected to the protective board with a thin plate, otherwise the protection will not work.

When individual elements are connected in series, their voltages are summed up, and the capacitance remains the same. Even from the same series, batteries have different characteristics, so they charge at different rates. For example, when charging to a total voltage of 12.6 V, the element in the middle can be recharged to 4.4 V, which is dangerous by overheating it.

In order not to overcharge unprotected elements, balancing cables are used that are connected to special chargers, for example: iMAX B6 and Turnigy Accucel-6.

Each Li-ion and Li-pol battery for domestic use has the most advanced surge protection, in the form of a voltage control circuit, a FET switch and a thermal fuse.

Balancing of protected elements is not required, since when the voltage on one of them rises to 4.2 V, charging is guaranteed to be interrupted.

When assembling a battery from elements without protection, there is a way out - put one voltage control board on all batteries, for example, by connecting them according to the 4S2P scheme - 4 in series, 2 in parallel.

Also, balancing of parallel connected elements is not necessary.

When the batteries are connected in parallel, their voltage remains the same, and the capacities are summed up.

About the capacity of lithium batteries

Capacity - The ability of a battery to deliver current, measured in milliamp hours (mAh) or ampere hours (Ah). For example, a battery with a capacity of 2 Ah can deliver a current of 2 A for one hour, or 1 A for two hours. But this dependence of current on the load connection time is not linear - at a certain point on the graph, if the current is doubled, the battery life is reduced by a factor of four. Therefore, manufacturers always indicate the capacity calculated when the battery is discharged with an excessively low current of 100 mA.

The amount of energy depends on the battery voltage, so nickel metal hydride cells with the same capacity have 3 times less energy than lithium ion cells:

NiMH- 1.2 V * 2.2 Ah = 2.64 watt-hours;
Li-ion- 3.7 V * 2.2 Ah = 8.14 watt-hours.

When looking for and buying rechargeable batteries, give preference to well-known companies such as Samsung, Sony, Sanyo, Panasonic. Batteries from these manufacturers have a capacity that most closely matches the one indicated on their case. The 2600 mA label on Sanyo cells is not much different from their actual 2500-2550 mA capacity. Fakes from Chinese manufacturers with a vaunted capacity of 4200 mA do not even reach 1000 mA, but their price is two times lower than Japanese originals.

To assemble a battery from lithium batteries, you can use:

soldering;
junction boxes;
Neodymium magnets;

Soldering during factory assembly is used extremely rarely, since the lithium element is destroyed by heat, while losing part of its capacity. On the other hand, at home, soldering will be the best way to connect batteries, since even a meager resistance on the contacts will significantly reduce the total voltage at the common terminals. You need to use a powerful 100 W soldering iron, and touch it to lithium batteries for no more than two seconds.

Powerful rare earth magnets are coated with nickel or zinc, so their surface does not oxidize. These magnets provide excellent contact between batteries. If you want to solder wires to a magnet, don't forget about the Curie temperature, above which any magnet becomes a pebble. Approximately allowable temperature for magnets is 300°C.

If you use a box for connecting batteries, then a big plus becomes obvious, since it will be easier to pick up batteries by voltage or change a damaged element.

Spot welding is the best way to connect lithium cells when assembling laptop batteries.

Buying a ready-made lithium battery for a car or motorcycle is not profitable when you can assemble it yourself at a lower price. You can save up to $ 70 if you do not buy a new laptop battery, but replace the elements in it yourself.

Savings when assembling high-power lithium batteries to power electric cars or autonomous power supply systems at home are difficult to judge, since in these cases there are additional costs for control and monitoring equipment.

How to make a battery with your own hands

A chemical current source (two-terminal), capable of recovering after a discharge, can be done by hand. Any chemical current source that has a periodic mode of operation (discharge - charge) consists of the following main elements:

electrodes: anode and cathode;
electrolyte;
dividing plates (separators);
frame;
contact terminals (conclusions).

Different pairs of chemical elements are used as anode and cathode. The anode has a negative charge - the reducing agent, the cathode - a positive charge - the oxidizing agent.

Both electrodes are immersed in an electrolyte. These are aqueous solutions of salts and acids that conduct electricity. When the battery (two-pole) is discharged to the load, the anode is oxidized and produces electrons that move through the electrolyte to the cathode. At the cathode, the process of reduction of the oxidizing agent takes place.

Important! When working on a load, the current flows through the two-terminal network from minus to plus, when charging from an external current source (IT) - from plus to minus.

To create one can of a simple copper and zinc battery, you will need the following parts:

copper wire 100 mm long;
galvanized plate with dimensions 25 * 50 mm;
gasket - a strip cut from a mosquito polyethylene mesh;
electrolyte - saline solution;
body made of opaque material - a sealed coffee cup with a lid.

It is necessary that the capacity for the battery is opaque.

The element is assembled in the following sequence:

the copper wire is twisted in a spiral, to increase the area of \u200b\u200bthe working surface, a branch is soldered to the upper end;
the galvanized plate is also twisted around the circumference, a branch is soldered to the upper part of the plate;
in the lid of the jar, two holes are made for the leads: in the center - for copper wire and closer to the edge - for the output of the zinc electrode;
a copper spiral is placed in the center, a zinc tube is placed around it, an insulating gasket is inserted between them;
electrolyte is poured: salt water (1 liter of water per 5 tablespoons of salt) or vinegar 15%;
loosely cover the lid, having previously threaded the leads into it.

A current source is connected to the received bank to charge a home-made battery. In this case, the lid must not be tightly closed. Or, for the release of gases during charging, many small holes are made in it (except for holes for leads). A home-made element has a plus on a copper electrode, a minus on a zinc one.

Attention! The smaller the distance between the elements of copper and zinc, and the larger the surface area of the electrodes, the greater the voltage will give such a battery cell.

Ideally, such an element produces 0.7 volts. The disadvantage of such a battery is its high internal resistance and rapid self-discharge.

How to make a powerful battery with your own hands

In order for a homemade battery to output more than 3.6 V DC, you need to assemble homemade cans into a battery connected in series. Single elements can be placed in a common housing.

Quality Li-ion 18650 charging systems

Lithium-ion sources of electricity of this type are widely used with various devices. They need constant recharging to keep them going. When charging, the voltage on the cell reaches a value of 4.2 V, after which it drops to 2-3 V. With deep discharges (below 3 V), the life of Li-ion 18650 is significantly reduced.

Important! Durability is affected by the number of charge-discharge cycles. This is the optimal number of cycles in which the battery capacity at the first charge (nominal) differs from the current capacity after charging by no more than 20%. The indicator is considered normal - 350-500 charge-discharge cycles.

There are special chargers for such batteries, but you can make them yourself using the circuit.

The current is adjusted by selecting the resistor R4 to the initial value of the charging current. It depends on the capacity of the battery. For example, if the battery capacity is 3000 mAh, then the charging current is 2-3 A.

Factory charge control systems independently adjust this parameter during the entire charge time.

Homemade battery from improvised means

How batteries can be made using electrolyte and electrodes is discussed above. Now about how to quickly assemble a single-acting current source. A battery is a galvanic source of electricity that has no ability to recover.

Method one: a lemon battery

Lemon pulp contains citric acid, it will serve as an electrolyte. A galvanized stud and a piece of copper wire act as an electrode. They are stuck into the lemon at a distance of 50-100 mm from each other. The oxidation reaction starts the movement of an electric current.

Method two: a jar of electrolyte

A liter glass jar is used as a container. Zinc and copper plates are taken as electrodes. Wires are attached to the plates, they themselves are lowered into a jar of electrolyte. They are 20% sulfuric acid solution. You can also use ammonium chloride (ammonia). For 100 ml of water, take 50 g of powder. The electrolyte level does not reach the edge of the can by 15-20 mm.

Carefully! Working with sulfuric acid in electrolyte preparation involves adding water to the acid, not the other way around. When preparing the solution, it is necessary to use glassware and a glass or wooden stick for stirring.

Method three: copper coins

The principle of using a copper cathode and an aluminum anode is considered in this method. The manufacturing process of the current source is as follows:

according to the shape of copper coins of the same size (copper penny), circles are cut out of aluminum foil and thick cardboard (the cover of an old book);
coins are cleaned by immersion in vinegar, cardboard circles are also impregnated with it;
Cardboard is inserted between the coin and a circle of foil, which serve as the cathode and anode.

The battery assembled in this way will work until the electrolyte that soaked the cardboard mugs dries.

Method four: a battery in a beer can

The body of the beer can itself (aluminum) serves as the anode (minus), graphite is used as the cathode. During manufacture, the following steps are taken:

the top of the jar is removed;
a foam circle with a diameter equal to the inner diameter of the can and a thickness of at least 10 mm is placed on the bottom of the can;
a graphite rod of a suitable diameter is inserted into its center;
the free space between it and the walls of the can is filled with coal chips;
saline solution (5 tablespoons of salt per 0.5 l of water) fills the resulting element;
the upper part of the device is filled with molten paraffin or stearin (from a candle);
wires are attached to the core and body of the can with the help of crocodile clips.

Method five: a potato battery

This is a variant of using a chemical oxidation reaction between copper and galvanized strips, potato pulp is used as an electrolyte.

Attention! The resulting voltages of such sources are so small that such designs can only serve as experiments to study the origin of electricity.

Method six: graphite rod

The graphite core is wrapped with a porous fiber cloth. An aluminum wire is wound on top of it in a spiral. The whole structure is lowered into a glass of suitable size, filled with "Whiteness". An aqueous solution of bleach serves as an electrolyte.

Despite all the variety of methods and types of home-made current sources, they all work thanks to electrolytic processes and chemical oxidation reactions. Properly matched pairs of cells for the anode and cathode, as well as the use of a suitable electrolytic solution, give real results. You can make a battery with your own hands to power gadgets and small devices.