Li-Ion and Li-Polymer batteries in our designs. Universal Charger for Lithium Polymer Batteries on the MCP73833 chip

Many, probably, there is a problem with charging Li-Ion battery without a controller, I have such a situation. The killed laptop went, in the battery 4 banks Sanyo UR18650A were alive.
I decided to replace in the LED flashlight, instead of three AAA batteries. The question arose about their charging.
Running in the internet found a bunch of scheme, but with the details we have Tugovo in the city.
I tried to charge from charging a cell phone, the problem in controlling the charge, you need to constantly monitor the heating, a little starts to heat up. You need to turn off the charge from charging otherwise the kayuk battery at best, and then you can arrange a fire.
I decided to do myself. Bought in the store bed under the battery. I bought charging on the flea market. For the convenience of tracking the end of the charge, it is advisable to find with a two-color LED which signals the end of the charge. It switches from red to green when charging.
But it is possible and ordinary. Charging can be replaced by uSB cord, and charge from computer or charging with USB output.
My charging is only for batteries without a controller. Controller I took from the old battery cell phone. It ensures that the battery is not rechargeable above the voltage 4.2 V, or less than 2 ... 3 V. Also, the protection scheme saves from short circuits, turning off the bank itself from the consumer at the moment of short circuit.
It is the DW01 chip and the assembly of two MOSFET transistors (M1, M2) SM8502A. There are with other labels, but the schemes are similar to this, and works in the same way.

Cell phone battery charge controller.

Controller scheme.

Another controller scheme.
The main thing is not to confuse the polarity of the switch controller with the bed and controller with charging. The controller's handcraft indicates the contacts "+" and "-".

In bed near the advantage contact, it is advisable to make a clearly noticeable pointer, red paint or self-adhesive film, in order to avoid stirring.
I collected everything together and that's what happened.

Charges wonderful. When a 4.2 volt voltage is reached, the controller turns off the battery from charging, and the LED is switched to the green. Charging is completed. You can charge other Li-Ion batteries, just apply another bed. Good luck to all.

Data Sheet MCP73831, reference data

A detailed description of microspectors from the manufacturer's company is a directory. The microcircuit is located in a convenient SOT-23-5 case. From reference data, charge current is set - 250mA

Typical inclusion scheme as charger, Recommended microchip:

A plus of such a scheme is the absence of low-level powerful resistors that limit the charging current. In this case, it is defined by a resistor connected to the fifth pine of the chip. Its resistance to lie in the interval from 2 to 10 com.

Charging assembly in the figure below, as you can see very miniature and compact:

The microcircuit in the process of work is very heated, but as shown tests. His main function Performs perfectly.

Probably, it is one of the simplest chargers for lithium-ion batteries, which can be collected with your own hands. Suitable, including for Li-Pol batteries.

Printed circuit boards 2 options under the scheme above, you can here:

During the test of the finished assembly: I started charging two lithium batteries of type 18650 with a total capacity of 4.4 cars. Dimmed them up to 3.2 volts and connected the charge, waited 10 minutes and measured the temperature of the thermocouple-67 degrees. If you believe the directory then the maximum normal working temperature For this chip 85 degrees, so I think that this heating is quite normal, especially since in the charging process the temperature will decrease as the battery will be charged with a smaller current, but more than 500m, I would not risk dragging from it without a radiator.

A lithium battery charging current can be configured in wide range With the help of external resistance. The LED indicator shows the status when the Li-Ion battery is fully charged. The maximum charging voltage is set from 4.1 to 4.5 volts, it is usually selected 4.2 V is a standard for most existing lithium batteries. For various microspects of the series, it is: MCP73831-2 4.2 V, MCP73831-3 4.3 V, MCP73831-4 4.4B, MCP73831-5 - 4.5 volts. There are only two resistance, a couple of capacitors, an indicator LED - and here charger Fully ready.

Progress is going forward, and to change the NICD traditionally used (nickel-cadmium) and NIMH (nickel-metal hydride) are increasingly coming lithium batteries.
With comparable weight of one element, lithium has a large capacity, in addition, the element voltage is three times higher than - 3.6 V per item, instead of 1,2 V.
The cost of lithium batteries began to approach the usual alkaline batteries, weight and size is much smaller, and besides, they can and need to be charged. The manufacturer says 300-600 cycles withstand.
The dimensions are different and it is not necessary to find it difficult.
Self discharge is so low that they lie and remain charged, i.e. The device remains working when it is necessary.

"C" means Capacity

It is often found notation of the type "XC". It is simply convenient notation of the charge current or battery discharge with the fraction of its capacity. Educated from the English word "Capacity" (capacity, capacitance).
When they talk about charging 2C, or 0.1C, usually mean that the current must be (2 × battery capacity) / H or (0.1 × battery capacity) / H, respectively.
For example, a battery with a capacity of 720 mAh, for which the charge current is 0.5C, it is necessary to charge 0.5 × 720mAh / H \u003d 360 mA current, this also applies to the category.

And you can make a simple or not very simple charger, depending on your experience and opportunities.

Scheme of a simple charger on LM317

Fig. five.

The application scheme provides a fairly accurate stabilization of the voltage, which is set by the R2 potentiometer.
Stabilization of the current is not so critical as stabilization of the voltage, therefore it is sufficient to stabilize the current with the help of the shunt resistor Rx and NPN-transistor (VT1).

The required charging current for a specific lithium-ion (Li-Ion) and lithium-polymer (Li-POL) battery is selected by changing the resistance of the RX.
RX resistance approximately corresponds to the following relation: 0.95 / IMAX.
The RX resistor value indicated in the diagram corresponds to the current of 200 mA, this approximate value depends also on the transistor.

It is necessary to provide a radiator depending on the charge current and input voltage.
The input voltage should be higher than the battery voltage at least 3 volts for normal operation of the stabilizer, which is for one bank? 7-9 V.

Scheme of a simple charger on LTC4054

Fig. 6.

You can drop the charge controller LTC4054 from the old cell phone, for example, Samsung (C100, C110, X100, E700, E800, E820, P100, P510).

Fig. 7. This small 5-foot chip marking "LTH7" or "Ltady"

I will not go into the smallest details of the work with the microcham, everything is in the datashet. I will describe only the most necessary features.
Charge current up to 800 mA.
Optimal supply voltage from 4.3 to 6 volts.
Charge indication.
Protection against KZ at the output.
Overheating protection (reduction of charge current at a temperature greater than 120 °).
Does not charge the battery at a voltage below 2.9 V.

The charge current is set by the resistor between the fifth conclusion of the chip and the earth by the formula

I \u003d 1000 / R,
where I is the charge current in amperes, R is the resistance of the resistor in Omah.

Lithium battery discharge indicator

Here simple schemewhich lights the LED when the battery is discharged and its residual tension is close to critical.

Fig. eight.

Transistors any low-power. The ignition voltage of the LED is selected by a divider from R2 and R3 resistors. The scheme is better to connect after the protection block, so that the LED has not discharged the battery at all.

Nuance durability

The manufacturer usually states 300 cycles, but if you charge lithium only 0.1 volts, up to 4.10 V, the number of cycles increases to 600 and even more.

Operation and precautions

It is safe to say that the lithium polymer batteries are the most "gentle" batteries from existing, that is, they require mandatory compliance with several simple, but mandatory rules, due to non-compliance with the trouble.
1. The charge is not promoted to a voltage exceeding 4.20 volts to the jar.
2. Does not leave short circuit battery.
3. The current discharges exceeding the load capacity or the heating battery above 60 ° C are not leaving. 4. The discharge is harmless below the voltage of 3.00 volts per can.
5. Battery heating is harmful above 60 ° C. 6. It is harmful to depressurize the battery.
7. It is harmful to storage in the discharged state.

Failure to comply with the first three items leads to a fire, the rest - to the full or partial loss of the container.

From the practice of many years of use, I can say that the capacity of the batteries changes little, but the internal resistance increases and the battery starts working less in time at high consumption currents - it seems that the container fell.
Under this, I usually put a tank more, which dimensions of the device allow, and even old banks that are ten years old, they work quite well.

For not very large currents, old batteries from cellular are suitable.

From the old laptop battery, you can pull out a lot of 18650 format batteries.

Where i apply lithium batteries

For a long time redid the screwdriver and the electrical turnover on lithium. I use these tools irregularly. Now even after a year of non-use, they work without recharging!

Small batteries put in children's toys, clock, etc., where there were 2-3 "tablet" elements from the factory. Where you need exactly 3V, add one diode sequentially and it turns out just.

I put in LED lanterns.

In the tester, instead of expensive and low-speed "Crown 9V" installed 2 banks and forgot all problems and extra costs.

In general, I put everywhere where it turns out, instead of the batteries.

Where I buy lithium and utility on the topic

Sold. Under the same link, you will find the charging modules, etc. utility utility facilities.

At the expense of the Capacity, the Chinese usually lie and it is less written.

Honest Sanyo 18650.

I liked small chips for simple charging devices. I bought them in our local offline store, but as they came out there ended, they were lucky for a long time. Looking at this situation, I decided to order them with a little wholesale, as the chips are quite good, and liked the work.
Description and comparison under the cut.

I did not in vain wrote in the title about the comparison, because during the way the dog could have grown up the microup appeared in the store, I bought a few pieces and decided to compare them.
The review will not have a lot of text, but quite a lot of photos.

But I will start as always with how it came to me.
It came complete with other different details, the Microuds themselves were packed in a bag with a latch and a sticker with the title.

This microcircuit is a chip of a charger for lithium batteries with a voltage of the charge 4.2 volt.
She knows how to charge batteries to 800mA.
The current value is set by the change in the nominal value of the external resistor.
It also maintains the function of charge with a small current if the battery is strongly discharged (the voltage is lower than 2.9 volts).
When charging up to voltage 4.2 volts and the drop in the charging current lower than 1/10 from the installed, the chip disables the charge. If the voltage falls to 4.05 volts, it will again go into charge mode.
There is also a way out for connecting the display LED.
More information can be found in, this chip there is much cheaper.
And he is cheaper with us, on the contrary, on the contrary.
Actually, for comparison, I bought analogue.

But what was my surprise when the LTC and STC chips were in appearance completely the same, both labeling - LTC4054.

Well, maybe even more interesting.
As everyone understands, the chip is so easy not to check, it is still necessary to the strapping from other radio components, preferably fee, etc.
And then, the comrade asked to fix (although in this context it is more red for) a charger for 18650 batteries.
Native burned down, and the charge current was small.

In general, for testing, you must first collect what we will test for.

I dwell on a datashet, even without a scheme, but I will give the scheme here for convenience.

Well, actually printed circuit board. There are no VD1 and VD2 diodes on the board, they have been added after all.

All this was printed, transferred to the cutting of the textolite.
To save, I made another fee on trimming, a review with her participation will be later.

Well, in fact, the printed circuit board is made and the necessary parts are selected.

And I will remove such a charger, for sure it is very famous to readers.

Inside him very complex schemeconsisting of a connector, LED, a resistor and specially trained wires that allow you to align batteries charge.
Just kidding, charger is in a block, included in the socket, and here simply 2 batteries connected in parallel and the LED constantly connected to the batteries.
To the native charger will return later.

Spread the scarf, said the native fee with the contacts, the contacts with the springs themselves dropped, they will still be useful.

He drilled a couple of new holes, on average there will be a LED displaying the inclusion of the device in the side - the charge process.

Speed \u200b\u200bB. new board Contacts with springs, as well as LEDs.
LEDs are conveniently inserted into the fee, then carefully install the board to your native place, and only after that it will be sought, then they will stand smoothly and equally.

The board is installed in place, the power cable is soldered.
Actually, the printed fee was developed for three pickup options.
2 options with miniusb connector, but in the installation options from different sides of the board and under the cable.
In this case, I first did not know how the cable is needed, therefore weighed short.
Also soldered the wires that go to the plus contacts of batteries.
Now they go on separate wires, for each battery its own.

That's how it turned out on top.

Well, now let's go to testing

On the left on the board, I installed Ali Micrukhu bought on Ali, on the right purchased offline.
Accordingly, they will be mirrored on top.

First Micruma with Ali.
Charge current.

Now purchased offline.

Current KZ.
Similarly, first with Ali.

Now from offline.

There is a complete identity of the microcircuit, which is no means not to please :)

It was noted that at 4.8 volts of the charge current of 600mA, at 5 volts drops to 500, but it was checked after warming up, it may still work with overheating, I have not figured it out, but the chips behave approximately equally.

Well, now a little about the process of charging and refinement to rework (yes, even it happens).
From the very beginning, I thought to simply install the LED on the indication of the included state.
It seems everything is simple and obvious.
But as always, she wanted more.
I decided that it would be better if during the charge he would be repaid.
I added a pair of diodes (VD1 and VD2 in the diagram), but got a small bummer, the LED showing the charge mode shines and then when there is no battery.
Rather does not shine, but quickly flickers, added parallel to the terminals of the battery capacitor to the 47MCF, after that it began to flare up very shortly, almost imperceptibly.
This is exactly the hysteresis of switching on re-charging, if the voltage dropped below 4.05 volts.
In general, after this improved, everything was fine.
The battery charge, shines red, does not shine green and the LED shines where there is no battery.

The battery is fully charged.

In the off state of the microcircuit, does not pass the voltage to the power connector, and does not be afraid of the twist of this connector, respectively, does not discharge the battery to its LED.

Not without temperature measurement.
I got a little more than 62 degrees after 15 minutes of charge.

Well, here it looks like a fully finished device.
External changes are minimal, unlike internal. The power supply for 5 / volts 2 amps of the comrade was, and quite quite good.
The device provides a charge current of 600mA per channel, independent channels.

Well, so the native charger looked. Comrade wanted to ask me to raise the charging current in it. It also could not stand it, where else to lift, slag.

Summary.
In my opinion, for the chip for 7 cents is very good.
Microcircuits are fully functional and no different from purchased offline.
I am very pleased, now there is a stock of Microus and do not wait for them when they are in the store (recently disappeared from the sale).

Of the minuses, this is not a ready-made device, therefore it will have to run, soldering, etc., but there is a plus, you can make a fee for a specific application, and not to use what is.

Well, in Tog to get a work product made with your own hands, cheaper than finished fees, and even under your specific conditions.
Almost forgotten, datasheet, scheme and tracing -

Today, many users have accumulated several workers and unused lithium batteries appearing when replacing mobile phones on smartphones.

When operating batteries in phones with your charger, thanks to the use of specialized chips to control the charge, there are practically no problems with the charge. But when using lithium batteries in various homemade, the question arises, how and how to charge such batteries. Some believe that lithium batteries already contain built-in charge controllers, but in fact, they are built-in protection schemes, such batteries are called protected. The protection schemes in them are intended mainly to protect against deep discharge and excess voltage when charging above 4.25V, i.e. This is an emergency protection, not a charge controller.

Some "self-dealers" on the site here will write that for little money you can order a special fee from China, with which you can charge lithium batteries. But this is only for lovers of "shopping". It makes no sense to buy what is easily going in a few minutes from cheap and common details. No need to forget that the ordered fee will have to wait about a month. Yes, and the purchase device does not bring such satisfaction as made by your own hands.

The proposed charger is capable of repeating almost everyone. This scheme Very primitive, but completely copes with its task. All that is required for quality charging Li-Ion Batteries, it stabilize the output voltage of the charger and limit the charge current.

The charger is distinguished by reliability, compactness and high output voltage stability, and, as is known, for lithium-ion batteries it is very an important characteristic When charging.

Charger Scheme for Li-Ion Battery

Charger circuit performed on adjustable stabilizer Voltage TL431 and bipolar NPN transistor of medium power. The diagram allows you to limit the battery charging current and stabilizes the output voltage.

The role of the regulatory element is the T1 transistor. The R2 resistor limits the charge current, the value of which depends only on the battery parameters. It is recommended to use a 1 W resistor. Other resistors can have a power of 125 or 250 MW.

The transistor selection is determined by the necessary charging current set to charge the battery. For the case under consideration, charging batteries from mobile phones, you can apply domestic or imported NPN transistors of medium power (for example, KT815, KT817, KT819). With high input voltage or using a small power transistor, a transistor is needed to install on the radiator.

LED1 (highlighted in red in the diagram), serves to visual battery charge alarm. When the discharged battery is turned on, the indicator glows brightly and as the charge dawns. The indicator glow is proportional to the battery charge current. But it should be noted that with full attenuation of the LED, the battery will still be charged with a current of less than 50mA, which requires periodic control over the device to exclude recharging.

To improve the accuracy of controlling the end of the charge, in the charger circuit added additional option Battery charge indication (highlighted green) On the LED2 LED, a low-power PNP transistor Kt361 and the R5 current sensor. The device may use any indicator variant depending on the required accuracy of battery charge control.

The diagram presented is designed to charge only one Li-Ion battery. But this charger can also be used to charge other types of batteries. It is only required to set the output voltage and charging current for this.

Manufacturing charger

1. Acquire or select from available, components for assembly in accordance with the scheme.

2. Assembling the scheme.
To test the performance of the circuit and its settings, collect the charger on the circuit board.

Diode in battery power supply (minus tire - blue wire) is designed to prevent discharge lithium-ion battery In the absence of voltage at the input of the charger.

3. Setting the output voltage of the circuit.
Connect the scheme to the power source with a voltage of 5 ... 9 volts. R3 trimmed resistance Set the output voltage of the charger in the range of 4.18 - 4.20 volts (if necessary, at the end of the setting, we measure its resistance and put the resistor with the desired resistance).

4. Setting the charger diagram.
By connecting a discharged battery to the diagram (as the inclusive LED info), I install the charging current (100 ... 300 mA) to the R2 resistor. With the resistance of R2 less than 3 ohms, the LED may not shine.

5. Prepare a board for mounting and soldering parts.
Cut the desired size from the universal board, carefully process the edges of the board with a file, clean and weigh the contact tracks.

6. Installation of the debt scheme for work fee
We carry parts from the mounting board to the working, soldering the parts, perform the missing layout of the compounds with a thin mounting wire. At the end of the assembly, we thoroughly check the installation.