entranceModule for charge Li-Ion batteries. Module for charge Li-Ion batteries Micro USB 18650 lithium battery charging
First you need to decide on the terminology.
As such discharge controllers do not exist. This is nonsense. There is no point in controlling the discharge. The current of the discharge depends on the load - how much she needs, so much will take it. The only thing to do when discharge is to keep track of the battery voltage to prevent its redistribution. For this apply.
At the same time, separate controllers charge Not only exist, but also absolutely necessary for the process of charging the Li-Ion batteries. It is they who set the right current, determine the end of the charge, follow the temperature, etc. The charge controller is an integral part of anyone.
Based on his experience, I can say that under the charge / discharge controller actually understand the battery protection scheme from too deep discharge and, on the contrary, reloaded.
In other words, when they talk about the charge / discharge controller, we are talking about built-in almost all lithium-ion batteries protection (PCB- or PCM modules). Here she is:
And too, they: 
Obviously, protection fees are represented in various form factors and are assembled using various electronic components. In this article, we will consider options for protection schemes Li-Ion batteries (or, if you want, discharge / charge controllers).
Charge-discharge controllers
Since this name is so well strengthened in society, we will also use it. Let's start, perhaps, from the most common option on the DW01 chip (Plus).
DW01-Plus.
Such a protective board for Li-Ion batteries is found in each second battery from the mobile phone. To get to it, it is enough just to tear the self-keeper with the inscriptions that the battery is placed.
The DW01 chip itself is a six-legged, and two field transistors are structurally performed in one case in the form of an 8-foot assembly.
The output 1 and 3 is to control the protection keys on the discharge (FET1) and reloading (FET2), respectively. Threshold voltages: 2.4 and 4.25 volts. Conclusion 2 is a sensor measuring the voltage drop on the field transistors, thereby implemented protection against overcurrent. Transistor transient resistance acts as a measuring shunt, so the triggering threshold has a very large spread from the product to the product.
The whole scheme looks something like this: 
The right chip with marking 8205a is the field transistors that perform the role of keys in the diagram.
S-8241 Series
SEIKO has developed specialized chips to protect lithium-ion and lithium-polymer batteries from overlapping / reloading. To protect one bank, the S-8241 series integrated circuits are used. 
The keys of protection from the projector and recharging are triggered accordingly at 2.3V and 4.35V. Current protection is activated when the voltage drops on Fet1-Fet2 is 200 mV.
AAT8660 SERIES.
LV51140T.
A similar scheme of protecting lithium single-baked batteries with protection against overloading, reloading, exceeding charge and discharge currents. Implemented using the LV51140T chip. 
Threshold voltages: 2.5 and 4.25 volts. The second leg of the chip is the input of the current overload detector (limit values: 0.2B during discharge and -0.7V when charging). Conclusion 4 is not involved.
R5421n Series.
Schemechnical solution similar to the previous one. In the operation of the microcircuit consumes about 3 μA, in the lock mode - about 0.3 μA (letter C in the designation) and 1 μA (letter F in the designation). 
The R5421N series contains several modifications that differ in the validity of the response voltage when recharging. Details are shown in the table:
SA57608.
The next version of the charge / discharge controller is only on the SA57608 chip. 
Voltages in which the chip disables the jar from the external circuits, depend on the alphabetic index. For details, see Table:
SA57608 consumes a sufficiently large current in sleep mode - about 300 μA, which distinguishes it from the above-listed analogues for the worse (there is consumed currents of the order of the microamper).
LC05111CMT
Well, finally, we offer an interesting solution from one of the world leaders in the production of electronic components on semiconductor - the charge-discharge controller on the LC05111CMT chip. 
The decision is interesting that the key MOSFET "are built into the chip itself, therefore only a pair of resistors and one condenser remained from the attached elements.
The transient resistance of the built-in transistors is ~ 11 bond (0.011 ohms). Maximum charge / discharge current - 10a. The maximum voltage between the outputs S1 and S2 is 24 volts (this is important when combining batteries in the battery).
The microcircuit is produced in the WDFN6 2.6x4.0, 0.65p, Dual Flag enclosure.
The scheme, as expected, provides protection against recharging / discharge, from exceeding the current in the load and from excessive charging current.
Charge controllers and protection schemes - what is the difference?
It is important to understand that the protection module and charge controllers are not the same. Yes, their functions intersect to some extent, but to call the charge controller module built into the battery would be an error. Now I will explain what the difference.
The most important role of any charge controller is to implement the correct charge profile (as a rule, it is CC / CV - direct current / constant voltage). That is, the charge controller should be able to limit the charging current at a given level, thereby controlling the number of "fillible" into the energy battery per unit of time. Excess energy is released as heat, so any charge controller in the process of operation is sufficiently warmed up.
For this reason, the charge controllers are never embedded in the battery (in contrast to protection boards). Controllers are simply part of the correct charger and no more.
In addition, no protection board (or the protection module, call as you want) is not able to limit the charge current. The board just controls the voltage on the bank itself and in the case of its output for pre-established limits, it opens the output keys, thereby turning off the jar from the outside world. By the way, the protection from the KZ also works on the same principle - with a short circuit, the tension on the bank is sharply lying and the protection scheme from a deep discharge is triggered.
The confusion between the protection of lithium batteries and charge controllers arose due to the similarity of the trigger threshold (~ 4.2B). Only in the case of the protection module there is a complete shutdown of the can from external terminals, and in the case of charge controller, switching to stabilization mode and gradually reduced charging current.
The Module for charging the Li-Ion batteries on the TP4056 chip has a low cost and easily charges your rechargeable element to a single ampere. It is very convenient that this scarf has a micro-USB connector and therefore connects via an ordinary USB cable directly to the charger or computer / laptop, that is, you do not need to have some kind of specific power supply.
This module has been protected from overlapping, reloading and large current. The triggering threshold with an excessive discharge is 2.3 - 2.5 V, the shipping charge 4.2 - 4.3 V, and the maximum current 3 A. If you do not need such a protector, then the battery can be connected to the charger without it.
Since the batteries have a different container and from this, each of them should receive a certain current (usually for lithium ionices is 1C), the manufacturer of the chip 4056 accounting for this and therefore you have the ability to adjust the current by changing the resistor rating. Below you see the table at which you can choose the current charge current. You can install a rapid / variable resistor and it will be very convenient to change the output current without soldering.
After powering on the charge of the charger, a blue LED be launched and quickly blinking red. Immediately after connecting the charged item, only a red light-emitting diode will be activated - the charge process goes. After reaching the battery voltage about 4.2 V (+ -1.5%), only the blue LED will remain, which indicates the end of the charge, the bank is fully ready for further operation. In the process of charge, the integral chip is a bit heats up a bit: with long use it is better to fix the radiator printed circuit board.
Lithium battery (Li-Io, Li-Po) are the most popular currently rechargeable sources of electrical energy. A lithium battery has a rated voltage of 3.7 volts, it is indicated on the housing. However, a charged 100% battery has a voltage of 4.2 V, and the discharged "in zero" - 2.5 B, there is no point in discharge the battery below 3 V, first, it will deteriorate from this, secondly, in the interval from 3 to 2.5 In the battery gives just a couple of percent of energy. Thus, the working voltage range is accepted 3 - 4.2 volts. My selection of lithium batteries, you can see this selection and storage of lithium batteries.
There are two options for connecting batteries, consistent and parallel.
With a serial connection, a voltage on all batteries is summed up, when the load is connected from each battery, a current equal to a total current in the circuit is in general the load resistance sets the discharge current. This you must remember from school. Now the most interesting, container. The assembly capacity with such a connection for a good equal to the battery capacity with the smallest container. Imagine that all batteries are charged 100%. See, the discharge current here is the same everywhere, and the first battery with the smallest capacity is first, it is at least logical. And as soon as it is discharged, it will be impossible to load this assembly. Yes, the remaining batteries are still charged. But if we continue to pull the current, then our weak battery will begin to be redesigned, and fails. That is, it is correct to assume that the tank of the connected assembly is equal to the tank of the very tight, or the most discharged battery. From here we conclude: it is necessary to collect a sequential battery at first of the same batteries on the capacity, and secondly, before assembly, they should all be charged the same, simply speaking by 100%. There is such a thing, called BMS (Battery Monitoring System), it can monitor each battery in the battery, and as soon as one of them is discharged, it turns off the entire battery from the load, this will be discussed below. Now it concerns charging such a battery. It is necessary to charge it with a voltage equal to the sum of maximum voltages on all batteries. For lithium it is 4.2 volts. That is, the battery of three is charged with a voltage of 12.6 V. See what happens if the batteries are not the same. The battery with the smallest capacity will be charged faster. But the rest are still not charged. And our poor battery will be fried and recharge until the rest are charged. Referee, I remind you, lithium also does not like very much and flies. To avoid this, remember the previous conclusion.
Let us turn to the parallel connection. The capacity of such a battery is equal to the sum of the containers of all batteries in it incoming. The discharge current for each cell is equal to the total current of the load shared by the number of cells. That is, the more Akumov in such an assembly, the greater the current it can give. But with a voltage there is an interesting thing. If we collect batteries that have different voltages, that is, roughly speaking charged to a different percentage, then after the connection they will begin to exchange energy until the voltage on all cells becomes the same. We conclude: Before assembling akuma, again, they must be charged the same, otherwise there will be big currents when the connection will be departed, and the discharged Akum will be spoiled, and most likely can even light up. In the process of discharge, the batteries also exchange energy, that is, if one of the cans has a lower capacity, the rest will not be able to discharge them faster themselves, that is, in a parallel assembly, you can use batteries with a different container. The only exception is to work at high currents. On different batteries under load, the voltage is in different ways, and there will begin to run current between the "strong" and "weak" akum, and we do not need it at all. And the same applies to charging. You can absolutely calmly charge different batteries in parallels, that is, the balancing is not needed, the assembly will balance itself.
In both cases considered, the charging current and discharge current must be observed. Charging current for Li-IO should not exceed half the battery capacity in amperes (1000 Mah battery - charge 0.5 A, 2 AH battery, charge 1 A). The maximum discharge current is usually specified in the datashet (TTX) battery. For example: laptop 18650 and batteries from smartphones can not be shipped with current exceeding 2 battery capacity in amperes (example: AKUM at 2500 mAh, it means that the maximum you need to take 2.5 * 2 \u003d 5 amps). But there are high-strength batteries, where the discharge current is explicitly specified in the characteristics.
Features of charging batteries by Chinese modules
Standard purchased charging and protective module for 20 rubles for lithium battery ( link to Aliexpress.)
(Positioned by the Seller as a module for one bank 18650) maybe it will charge any lithium battery, regardless of the form, size and container Prior to the correct voltage of 4.2 volts (voltage of a fully charged battery, under the string). Even if it is a huge lithium package for 8000mAh (of course it is about one cell by 3.6-3.7V). The module gives a charging current of 1 ampThis means that they can be charged without fears to charge any battery with a capacity of 2000mAh and higher (2Ah, which means the charging current - half the tank, 1a) and, accordingly, charging time in the clock will be equal to the battery capacity in amps (actually a little more, one and a half or two hour for every 1000mAh). By the way the battery can be connected to the load during the charge.
Important! If you want to charge a smaller capacity battery (for example, one old jar at a 900mAh or a tiny lithium bag at 230mAh), then the charging current 1a is a lot, it should be reduced. This is done by replacing the R3 resistor on the module according to the applied table. The resistor is optional to SMD, the most common one will suit. I remind you that the charging current should be half of the battery capacity (or less, not scary).
But if the seller says that this module for one bank is 18650, can they charge two banks? Or three? What if you need to assemble the capacious PowerBank from several batteries?
CAN! All lithium batteries can be connected in parallel (all the advantages to the advantages, all cons by cons) regardless of the tank. Speeded parallel batteries retain the operating voltage of 4.2V and their container is developing. Even if you take one jar at 3400mAh and the second to 900 - it turns out 4300. Batteries will work as one whole and discharge will be proportional to its container.
The voltage in the parallel assembly is always the same on all batteries! And no battery can physically be discharged in the assembly before others, the principle of reporting vessels works here. Those who claim the opposite and say that the batteries with a smaller capacity are discharged faster and die - confused with a consistent assembly, spit them into the face. 
Important! Before connecting to each other, all batteries must have about the same voltage, so that equation currents are not flowed between them, they can be very large. Therefore, it is best before assembling simply charge each battery separately. Of course, the time for charging the entire assembly will increase, since you use the same module on 1a. But you can spararal the two modules by receiving the charging current to 2a (if your charger can give so much). To do this, it is necessary to connect with jumpers all similar terminals of the modules (except Out- and B +, they are duplicated on cards by other fives, and so will be connected). Or you can buy a module ( link to Aliexpress.), where chips are already in parallel. This module is able to charge a current of 3 amps.
Sorry for completely obvious things, but people are still confused, so you have to discuss the difference between the parallel and consistent compound.
Parallel Compound (all the advantages to the pros, all cons by cons) retains 4.2 volt battery voltage, but increases the container, folding all the containers together. All Power Banks use a parallel connection of several batteries. Such an assembly can still be charged from a USB and the voltage increases up to the output 5V.
Consistent The compound (each plus to minus the subsequent battery) gives a multiple increase in the voltage of one charged bank 4.2V (2S - 8.4V, 3S - 12,6V and so on), but the container remains the same. If three batteries are used for 2000mAh, the assembly capacity is 2000mAh.
Important! It is believed that for consistent assembly, it is necessary to use only the batteries of the same container. In fact, it is not. You can use different, but then the battery capacity will be determined by the smallest tank in the assembly. Fold 3000 + 3000 + 800 - get an assembly to 800mAh. Then the specialists begin to sway that the less capacious battery will be quickly discharged and die. And it does not matter! The main and truly sacred rule - for consistent assembly always and necessarily you need to use the BMS protection fee for the desired number of cans. It will determine the voltage on each cell and turn off the entire assembly if some kind of discharge is first. In the case of a bank for 800, it will also be discharged, bms will turn off the load from the battery, the discharge will stop and the residual charge of 2200mAh on the rest of the banks will not be valid - it is necessary to charge.
The BMS fee in contrast to the single charging module is not a sequential assembly charger. For charging need configured source of the desired voltage and current. About this gamever shot a video, so do not waste time, look at it, there is much thoroughly about it.
Is it possible to charge a consistent assembly by connecting multiple single charging modules?
In fact, with some assumptions - it is possible. For some homemakes, a scheme has proven to use single modules connected also in series, but for each module, a separate power supply is needed. If you charge 3s - take three telephone charging and connect each one to one module. When using one source - nutrition short circuit, nothing works. Such a system also works and how the assembly protection (but the moduli is able to give no more than 3 amps) or simply charge the assembly shipping, connecting the module to each battery to a complete charge.
Accumulator charge indicator 
Also a pressing problem - at least approximately know how many percent of the charge remains on the battery so that it does not discharge in the most responsible moment.
For parallel assemblies by 4.2 volts, the most obvious solution will immediately purchase a ready-made PowerBank fee, which already has a display that displays the charge percentage. These percentages are not super-accurate, but still help. The issue price is approximately 150-200rub, all are presented on the website of the Gaiver. Even if you are collecting not Powerbank and something else, this fee is quite cheap and small to place it in the homemade. Plus it already has a battery protection and protection function.
There are ready-made miniature indicators on one or more cans, 90-100r 
Well, the cheapest and folk method is to use the MT3608 increasing converter (30 rubles), configured by 5-5.1V. Actually, if you make Powerbank on any 5 volt transmitter, then you don't even need to buy anything. The revision is to install a red or green LED (other colors will operate on another output voltage, from 6V and above) through a current-limiting resistor 200-500 between the output plus terminal (it will be plus) and the input plus (for the LED it will turn out to be minus). You are not mistaken, between two pluses! The fact is that during the operation of the converter between the advantages, the difference of voltage is created, +4.2 and + 5V, the voltage is 0.8V. When the battery discharge, its voltage will fall, and the output from the converter is always stable, then the difference will increase. And at a voltage on a bank, 3.2-3,26VI, the difference will reach the necessary value to light the LED - it begins to show that it is time to charge.
How to measure the capacity of batteries?
We are already accustomed to the belief that Iamaks B6 needs for measurement, and it costs money and for most radio amateurs is excessive. But there is a way to measure the capacity of 1-2-3bachal batteries with sufficient accuracy and cheaply - a simple USB tester.
A lot of ten pieces was bought, for reworking the power of some devices on Li-Ion batteries (now there are 3AA batteries in them), but in the review I will show another option to apply this board, which, although it does not use all its capabilities. Just from these ten pieces we only need only six, and 6 with protection and a pair without protection it turns out less profitable.
Based on the TP4056 charge charge with the LI-ION batteries with current to 1a is designed for full charge and battery protection (for example, popular 18650) with the possibility of connecting the load. Those. This fee can easily be easily embedded in various devices, such as lanterns, lamps, radio receivers, etc., with power from the built-in lithium battery, and charge it without removing any USB charging through the microUSB connector. This board is perfect for repairing burnt li-ion batteries.
And so, a bunch of boards, each in an individual sachet ( here already certainly less than bought)
Looks like a scarker like this: 
You can consider closer items 
On the left microUSB power input, the power is also duplicated by platforms + and - under the soldering.
In the center of the charge controller, TPower TP4056, over it a pair of LEDs displaying either the charge process (red) or the end of charge (blue), under it resistor R3, changing the denomination of which you can change the battery charge current. TP4056 charges the accumulators according to the CC / CV algorithm and automatically completes the charging process if the charge current decreases to 1/10 from the installed.
Nameplate of resistance and charging currents, according to the controller specification.
- R (com) - I (MA)
- 1.2 - 1000
- 1.33 - 900
- 1.5 - 780
- 1.66 - 690
- 2 - 580
- 3 - 400
- 4 - 300
- 5 - 250
- 10 - 130
From the reverse side of the board there is nothing, so it can be, for example, glue. 
And now an option to apply charge and protect the Li-Ion batteries.
Nowadays, Li-Ion batteries with voltage of 3.7V, i.e., are used in almost all amateur format video cameras. 1s. Here is one of the additionally purchased batteries for my camcorder.
I have several of them, production ( or labeling) 4500mach capacity ( not counting the original, at 1790mach)
Why do I need so much? Yes, of course, my camera is charged from BP with 5V 2A ratings, and bought a separate USB plug and a suitable connector, I can now charge it and from plundays (and this is one of the reasons why I, and not only me, they are so much), yes But it is uncomfortable to be removed to the camera to which the wire also stretches. So you need to somehow charge the batteries outside the camera.
I already showed this charging, as well as batteries purchased in the DealExtreme store ( well, more precisely, some of the accumulators were)
Yes, yes, it is she, with a rotating fork of the American standard 
That's how it is easily divided 
And so, the charge charge and protection of lithium batteries is implanted in her 
And of course, I brought a pair of LEDs, red - the charge process, green - the end of the battery charge 
The second board was installed in the same way, in charge from the Sony camcorder. Yes, of course, the new models of the Sony video cameras are charged from USB, they even have a non-disconnecting USB tail ( stupid in my opinion solution). But again, in the field, to shoot on the camera, to which the cable from the panibank is stretched less convenient than without it. Yes, and the cable should be long enough, and the longer the cable, the greater its resistance and the more loss on it, and to reduce the cable resistance increasing the thickness of the core, the cable becomes thicker and less flexible, which does not add convenience.
So from such charges and protection of Li-Ion batteries to TP4056, you can easily make a simple automatic battery charger with your own hands, to remake the charger to power from USB, for example, to charge batteries from panibod, make the charger repair if necessary.
All written in this review can be seen in the video version:
P.S. The remaining boards will be triggered to work as part of the UPS for Arduino, Raspberrypi, Bananapi and the like.
P.P.S. All successful fridays.
Hello, friends!
Today I would like to tell about one pribrud (more precisely - about a set of 10 such priblud), with which you can charge the batteries with a face value of 3.6-3.7V. The same board is also protected against overpar battery discharge.
So, drove!
The first thing I would like to emphasize attention are sizes. This fee is not much more than the usual microSD flash drive.
There is one entrance to 5V. Please note the microUSB socket and 2 holes with it with it - this is the same entry, i.e. They are topped. In other words, you can connect to the board through the microUSB, and it is possible to soldily with the same success directly to the board, it will not see the difference.
The remaining 4 contacts - two go to the battery and two more - on the load (for example, on some LED panel).
More accurate fees are 17x26.5mm.
And on this about the appearance is enough, we turn to the preparation for testing. To do this, I needed to discharge the battery without protection (in my case it is a Panasonic at 3400mAh, I already wrote a rather strain review on it).
At the isolate on the battery, I ask you to pay attention, because The battery was discharged in a flashlight with an aluminum case. Simply put, the "mustache" of the battery could simply turn the same building.
I also needed to roll to the 4 wire board. The tips I called the NShVI shocks of red and black, so as not to get used where plus and where is minus).
As you already guessed, the first test will be charged.
For this, I discharged the battery almost in zero (in the sense of percent, not by voltage).
Especially for those who have now happened to the heart attack - according to the datasheet on these batteries calmly carry the discharge to 2.5V, and here a little more.
So, run the battery charging process.
We have almost 1,1A. Gathering. Yes, I do not argue, promised 1a we got, but the board at the start does not ceremony with the battery. I already have a similar FC-75 board. So, she charges 95-100ma to such a degree of discharge, no more. And only then, when the battery recharged a little, it serves a current of 1a. However, FC-75 does not have access to the discharge of batteries, so it can be used exclusively as a charger. Once again - FC-96 did not ceremony with the battery and immediately served a current 1a. But she is fortunately, a little later you will understand why.
I chuckled the multimeter and gave the battery fully charged. The charge is over, as evidenced by the green light.
Now let's turn off the USB cable and see, until the voltage charges the battery.
4.15V This, of course, good (i.e., the battery is guaranteed will not be redundantly charged), but I would like to see on the display 4.2V. If someone has doubts about the accuracy of the testimony - I have long answered you. Those. This fee is slightly unshaotable batteries.
Now I will tell you how I collected the scheme for the category. By the way, the scheme is this.
For convenience, I first disconnected the battery from the board and only then started to attach the load. So, when I connected the battery back, nothing happened - the fee did not earn. Then I connected the USB cable, after 2-3 seconds, it turned off and the diagram after that has already started working. Testo I turned off the load (but did not disconnect the battery), and then connected the load back.
Those. In fact, we found out that after disabling the USB cable, the board continues to work from the battery. However, if you turn off the battery, the board is completely cut down and you can only run it via USB (well, or through the same 2 contacts located near USB-Micro, there will be no difference).
Now go to the test dance. To begin with, let's see what current I will succeed to suck from the battery through this board using the load.
I involved all 4 switches on the load. As you can see, received more than 2,2A.
I again removed the multimeter from the chain and left the battery to be discharged before the protection is triggered. At the same time, I tried not to miss the moment of triggering. And I was lucky - the cut-off worked right at that moment when I once again looked to see how it was there.
Note - measure the voltage on the contacts OUT + and OUT- showed 0B, i.e. The cut-off really worked. It remains only to measure the voltage on the battery itself.
We get almost 3.3V. Multimito for Panasonic, however! Let me remind you that Panasonic datasheet can be discharged to 2.5V. Those. With a deeper discharge, we calmly discourage the battery about 400-500mAh. Here's the answer to the question why she will not be ceremony at the start with batteries. That's right - because it does not need it, because To the end, it will still not discharge the battery. Yes, I do not argue if the minimum voltage of 3B is installed on the datashet, then the discharge from 3.3V to 3B really little will give. But in the case of Panasonic, it is better to discharge at least up to 2.7-2.8V.
So, what did we eventually get?
1) immediately and without parsing takes the battery charging current 1a
2) a little unscrewed batteries
3) It is too early cut off the discharge of batteries.
However, all these numbers give a practically 100% guarantee that the battery connected to this board will never be discharged too deep and will never be redundantly charged. So the board is quite suitable for use.
I repeat, in the set, they are supplied 10 pieces. Where to apply them - decide for yourself. I dispose of it as follows:
1) 5 such boards I use for assembling your own beliefs.
I have 2 sets of such transducers (5 pieces in the set)
As you can see, each of these boards has 2 contacts for connecting the battery and one USB output. So, the USB-inputs of the FC-96 boards I will be represented - this will give me the opportunity to charge my beliefs in the current as a whole ampere (!!!) - on 1a per 1 battery. USB outputs of this "glued" set I also fought. Each board from this set calmly displays a 1 to the voltage drop below 5 volts.
For those who do not understand, this scheme will be on each battery.
2) Another 1 feefC-96 I use for self-eightened emergency lighting (and then the recently turned off the steel). The idea of \u200b\u200bthis - to OUT "AM FC-96 boards connect a boost, thereby increasing the voltage up to 12V and make something like a night light. Most likely, this" night light "will be on LED lamps, with halogens (and even more incandescent lamps ) There is no special desire to bother.
3) I also want to experiment with my Bosch Ixo screwdriver, it is also on a lithium-ion battery (one). I will try to remake it in such a way that it is possible to charge via USB. And then his native fee is somehow curved - it charges only to 4.05V when tolerance in 4.2. And after all, its FIG reconfigure! It turns out that the battery capabilities are not used.
Well, the remaining 3 boards so far will be in stock. Life is long - sooner or later will be useful. In addition, I have 3 batteries from Nokia Lumia 520, they are also lithium-ion. Perhaps they will also go to something type of night light.
By the way, where would you apply the board mentioned in the review? The question is purely academic, for the sake of interest. Please unsubscribe in the comments.