User review of the popular charger model IMAX B6*clone*after three years of operation.

Hello everyone. Hello to site users and ordinary readers of this article.

Today my article will be devoted to a user review of the popular IMAX B6 model.

Although the model is not new—there are already a bunch of new versions of it—my version is on sale and is in demand. I hope this reviewer will be of some interest.

I’ll start with a short lyrical introduction - for those who don’t know - WHY? - WHY? WHAT IS THIS CHARGE FOR?

Today it is believed that smart charging is the best thing that can be used to charge different types of batteries.

Usually it has all the necessary settings for working with batteries.

Such charging makes this task easier - and what can I say - it’s SIMPLE AND CONVENIENT, you don’t need to rummage through a bunch of information on batteries to charge them correctly - SMART PEOPLE stuffed ALL THIS into the charger - for which special thanks to them.

Ok, so the lyrics are over, let's get down to business.

WHAT I LIKED AND DON'T VERY MUCH ABOUT THIS CHARGER - for all the time it was used.

CLEAR MENU AND NAVIGATION (in English) - considering that this was my first smart charger + at the time of purchase there was little information on it - the instructions received upon purchase were enough for me to understand the necessary functions.

CHARGING ALMOST ALL CURRENT TYPES OF BATTERIES is very convenient...because everything is in one compact device.

SELECTING PARAMETERS FOR CHARGING - as in manual mode (if you know and understand batteries well) - we select what we need, save it and charging works in these parameters - for all types of batteries.

For less experienced users, like me, there are AUTO MODES for almost all types of batteries, which is very convenient.

POSSIBILITY OF CHARGE-DISCHARGE AND CYCLES - for nickel-cadmium and metal hydride batteries. Selecting these functions separately,

Selecting the number of cycles (in my version 1 -5)

Selecting the time interval between cycles (max 60 minutes in my version, if I’m not confused). After such a cycle, you can see the state of the battery.

The choice of charge current from 0.1 A-5A per charge and 0.1-1A-discharge is very convenient.

DIFFERENT MODES FOR LITHIUM BATTERIES - including the balancer function - when you can track the status of each bank separately online.

BATTERY CHARGING LIMIT FUNCTION - (the amount poured into the battery - not to be confused with the charge current). For example, I have a couple of half-dead but working batteries - which are charged and do not turn off - the battery almost boiled and heated up. Here I just set limit on the fill (5A for example) - after which the charging was turned off - see the video in more detail. Who knows what this function is called correctly - tell me - I will be grateful.

INPUT VOLTAGE LIMIT FUNCTION - convenient when powering the charger from the car's cigarette lighter, so as not to drain it to the point where it is impossible to start the car (the limit is set manually). This feature has come to the rescue more than once while fishing and on vacation.

On the plus side, it seems that everything is what I noticed when using it for myself - its functionality is, of course, very rich - anyone interested can look at a detailed review on the Internet - there are a lot of them on the Internet.

ON THE MINUSES - which I canceled for myself.

IT HEATS VERY MUCH - especially in the summer... during long-term operation (there is no active cooling - only passive cooling - through the aluminum body) - on the other hand, it works quietly.

THERE IS NO OPPORTUNITY TO TURN OFF THE BACKLIGHT - it lights up bright blue - not always convenient when using it in the house.

basically that's all.

And so, in general, I’m happy with the charger; later I acquired its original version; I’ll devote one of the following articles to this.

Dear readers... some moments are very long and difficult to describe - watch my video on this review - I hope it will add something.

That's all for today - until the next article.

The iMax-B6 universal charger is rightfully considered a popular charger. Any aircraft modeller or person who owns Li-Po batteries will recognize the blue shaitan box from afar.

appearance of the shaitan box

For its time, charging turned out to be so revolutionary and simple that everyone began to copy it. There are several versions of the charger:
- The original was called BC-6 and was produced by Bantam based on ATmega32/ATmega32L.
- Then SkyRC successfully licked it, and everyone forgot about Bantam.
- An exact copy of SkyRC on ATmega32 made in the basement (I came across this one).
- A copy with differences in the circuit and board.
- Charging on the chip . It’s difficult to call it a clone since this device is based on a completely different microcontroller and only looks similar to the iMax-B6.
- In 2016/2017, the Chinese reached the bottom of optimization and released a new charger that only charges lithium normally. The chip is in a TQFP48 package and without markings. They assume that this is STC or ABOV MC96F6432. It looks like Vanga was mistaken - it turned out to be MEGAWIN MA84G564. There are no third-party firmwares and it looks like there won’t be any.

There are at least three diagrams of the original iMax-B6 circulating online. The most successful attempt to draw a diagram and understand how it works was made by a user electronik-irk. With their developments he shared in the "Born with a Soldering Iron" community.

But in any barrel of honey there is always a fly in the ointment. It was also found in the iMax-B6. This is a problem with Δv when charging 1.2 volt Ni-Ca and Ni-Mh batteries. At one time I wrote to the community about the problem with Δv, but never received a response. My opinion is that difficulties with Δv arise due to several jambs. The first is that during switching on and with each measurement, a surge of about 3-4 volts occurs on capacitor C21 and the output terminals, which introduces quite a distortion of Δv in 1.2 volt batteries.

power circuit diagram

This problem is easily solved by adding a resistance R128 with a nominal value of 4.7 kOhm in parallel with the capacitor C21. As a bonus, this resistor corrects a bug feature of some iMaxes - dying when turned on without a load. In this case, VT26 or VT27 usually lights up.

You need to solder R128 here

The second problem is the small capacity of the ADC and noise from the power supply and digital circuits. 10bit is barely enough for the range 0V - 30V with an accuracy of 0.29mV. To somehow facilitate the operation of the ADC, you need to carry out a set of measures:
- Increase the stability of the reference voltage.
- Change the native iMax firmware to cheali-charger. This firmware uses a trick with resampling and adding artificial noise. After all these modifications, you will be able to catch Δv from Ni-Ca/Ni-Mh at charging currents > 0.5C

The iMax built on the ATmega32 uses a not very accurate reference voltage source of 2.5 volts on the base TL431. Its stability can be slightly increased by soldering an electrolytic capacitor with a capacity of 10 µF between AREF and ground.

supporter in the upper left corner

I will describe in part about flashing, calibrating and activating the artificial noise mode.

UDP: As correctly noted Loll Ol in the comments, the TL431 is very critical of the output capacitor capacity. Zones of stable operation are marked in red: 0.001mF - 0.01mF and 10mF.

TL431 stability chart

If you are into electronics, you may have a smart charger Imax B6 (mini). The kit does not include balancing connectors and a box for installing batteries. Of course, craftsmen are starting to make them with their own hands from scrap materials or ready-made purchased spare parts. Some people do it better, and some don't. In this post I’ll tell you in detail and show you how to do it.

To make it I needed:

1. Boxing 2×18650;

2. Boxing 4×18650;

3. Balancing connectors 2s 3s 4S 5S 6s;

4. Wires AWG18;

5. Banana probes;

6. Screw terminal blocks 2EDG-5.08-4P + 2EDGV-5.08-4P - 2 pcs.;

7. Foil fiberglass.

And so, we need to make a printed circuit board

Made in Sprint Layout, . Download PCB, lay6 format

After etching the board, we assemble and solder everything.

Below in the photo the connector is connected to 5 five cans. We will not use the sixth compartment of the holder, since we are charging 5 batteries.

Connection diagram to the balancing connector Imax B6

It doesn’t matter what kind of charger you have, the original is not the original, they all have five sockets for balancing up to 6 lithium batteries. To connect to the balancing socket, connect all the banks in series, then the 1st wire (red) of the connector goes to the plus of the assembly, and the last wire to the minus of the assembly, the connections between the banks go to the intermediate wires of the connector. On ( + ) first can and ( — ) last, you need to solder the banana probes. Below is a diagram for connecting the maximum number of batteries.

In this example we see the maximum connection of batteries, 6 pieces. To connect five, four... do the same, do not forget to observe the polarity.

I bought a relatively cheap universal amateur device for charging most common types of batteries. Unfortunately, the device turned out to be unsuitable for its intended use, although it was completely corrected. The problem is poor or incorrect implementation of literally all of its functions.

I won’t go into the details of how the Imax B6 actually works; a user manual is available online, and the charger is so popular that you can easily find many reviews on it. I will only describe the features of this fake.

I chased the cheapness and got the corresponding result. Although now you can easily get exactly the same thing for 30-40 bucks, the Chinese have mastered this type of counterfeit well. The recipe is simple - install your own Nuvoton microcontroller, sometimes upgraded to Atmel, and put in a microprogram that is as similar in appearance as possible to the original one. The problem is that this program is only visually (in the menu) similar to the original, but the implementation of the functions is disgusting.

Let's look at the device from all sides and look inside.

Perhaps in the far left corner there should be a chip responsible for connecting to the computer. It’s funny that instead of paths, this entire place was left as a single polygon, but they forgot to remove the silk-screen printing with the mask. The option of connecting to a computer is not provided here initially. The microcontroller is located under the display.

Nickel discharge (NiCd, NiMh)

When discharging nickel, the voltage is measured under load. I don’t know about others, but even my good (but old) batteries have a fairly high internal resistance. As a result, when discharging with a high current, the process may not even begin due to a strong drop in battery voltage. In principle, this is normal. In this mode, you can select the discharge voltage and compensate for this drawdown.

Lithium discharge (Li-Ion, Li-Po, Li-Fe)

The programs for all types of lithium are identical, only the threshold voltages differ, upon reaching which the discharge stops. This voltage cannot be set manually; it depends on the set charge voltage, which is also hardwired and depends only on the selected battery type.

For lithium, the program reduces the current at the end, but due to some problems with measurements it cannot complete the process; it sucks out the last drops for hours, and the lower threshold is very often ignored. The charger can easily drive the voltage below a safe level, which damages lithium batteries.

When connecting a battery assembly, only part of the cells may be severely discharged; the device does not take into account the possibility of such an outcome; the balancing connection is not used to assess the condition of individual cells. You can quickly ruin an expensive one even if the entire assembly is discharged to a safe level. In the only attempt to completely discharge the assembly to measure its capacity, the cell voltage spread at the end of the discharge turned out to be 2.5-3.6 V, with a safe level of about 3 V.

After overdischarge, the charger itself can no longer charge the battery back, giving a “low voltage” error.

The original Imax B6 had a 5W discharge power limit, here that limit is raised to around 7-8W. This is probably why the device gets very hot when the batteries are low, there is no fan inside, all cooling is done by transferring heat to the case. But I have not held the original B6 in my hands, it may have the same problems at 5 W.

Charging Nickel

The manufacturer claims charging with high currents, 1-2 C up to 5 A. But in this fake, in most cases, you can risk setting only 0.2 A. If you set a higher value, then with a high probability the device will consider that several cells are connected in series and will supply increased voltage, which will damage the batteries. Moreover, the excess voltage will not be supplied immediately, but after a small recharging and re-evaluation, i.e. you can connect the battery, see that everything seems to be in order, go off to do other things and return to the burnt house.

The end of charge according to Delta Peak is implemented incorrectly, or not implemented at all, which is why the battery is often undercharged. Even when starting the program, errors like “short circuit”, “insufficient voltage” and “excessive voltage” appear; you have to restart it several times until it works.

Lithium charging (normal, fast, storage)

Charging a lithium battery is usually divided into two stages. At the first stage, charging occurs with a constant current of a given value; here charging can produce up to 5 A, and there are no problems with this. At the second stage, the battery is recharged with a voltage source.

And for some reason this second stage works very slowly, sometimes delaying the process for hours, I have not found any reason for this. This probably has something to do with the erroneous final voltage for some batteries. If you charge a 4.2-V bank to 4.1 V, then charging always occurs within an acceptable time frame.

The device has three separate charging programs - normal, fast and storage. I did not find any significant differences between them in this version of B6. The storage mode in the original charger should bring the battery to 3.85 V, discharging or charging it, here this mode always simply charges the battery to the maximum, but in the options of this mode there remains a limitation from the original program - the charge current cannot be more than 1 A. In general , draining the battery for storage is a bad idea. And you can charge up to 100%, although a level of 3.85 V is probably more preferable; it’s not for nothing that batteries come from the factory charged to approximately this voltage.

Lithium charging with balancing

Even more nonsense occurs when charging with a balancing cable connected. The fake B6 actually knows how to balance cells, but only if one of the cells does not exceed the maximum permissible value, for example due to charging in another charger with a b O higher final charging voltage. In this case, this “B6” begins to slow down, probably due to the fact that it simply does not know how to discharge an overcharged cell in such cases, which is why the balancing process simply stops. Solution to the problem: discharge the entire battery a little, and then start balancing again.

Balancing here ends when the voltage difference reaches no more than 0.01 V, for example, after balancing the 4S assembly at 16.8 V (4.2 V per cell), the voltage of all cells will be in the range of 4.19-4.20 V. Correction: If the battery, wires or contacts are in poor condition, you can end up with a much larger spread.

As with single-cell charging, reducing the charging voltage to 4.1 V noticeably speeds up the process.

Some more features

I have not tested working with lead batteries. This function was originally made on the “if only it was” principle, and I’m not going to spoil expensive batteries for the test, especially considering the tendency of this charger to discharge the battery below the safe threshold, which is as important for lead as for lithium.

The voltage shown on the display during charging or discharging has little to do with the voltage on the battery. This is some kind of internal evaluation value that is in no way interesting to the user. If capacitance is measured on the basis of such incomprehensible values, then this function does not exist either. Perhaps the problem is bad wires and contacts.

The power supply is not included; you need an 11-18 V unit with an output of at least 50 W. If you want to take a model with a power supply, look for the B6AC. I used a 16V/4.5A (72W) power adapter from an old laptop and it worked great. The kit includes cables with crocodile clips for power supply from a car battery.

The original B6 can be connected to your computer using . This fake does not have such a function or a corresponding menu item. I was also really looking forward to this feature. Also, unlike the original, this fake does not have a calibration function.

Sometimes letters from previous messages remain on the screen.

Original Imax B6

Since in this fake all the functions of the original B6 are copied as accurately as possible, you can get some impression of the original device.

The charger has non-switchable protection functions against short circuit, low and high voltage. In practical use, this protection only gets in the way, being only a weak implementation of protection against a fool running, for example, a program for lithium on nickel. With problem batteries, protection also complicates the work, for example, you have to keep another charger on hand to recharge the batteries to an acceptable level if they were overdischarged. But there is also a useful type of protection - stopping when the circuit breaks, and it also works for all inputs of the balancing connectors.

Switching between lithium types is done as a custom setting, for which you need to go through the entire device menu. Very uncomfortable. Also, when working with lithium, there is no way to indicate the charge and discharge levels yourself. There is no possibility of charging up to 4.35 V.

For the price of the original B6 there could be a much more advanced display here. The monochrome display of two lines of 16 characters in such a complex device looks simply ridiculous. The device’s firmware is also not very informative and produces mostly useless information.

conclusions

I didn’t use the device for long, but I already realized that out of all the programs, you can only use 1-2, and even then only if you don’t have a normal device at hand and you have a lot of free time.

Since this type of counterfeit based on the Nuvoton chip is already very popular, there is a chance that they will come up with alternative firmware for it, as was done with the original B6 and more accurate copies. The main thing is that the hardware allows you to do all the things that the original device does.

What did I want from this charger? A little bit of everything and in working order: nickel fast charging, balancing charging, capacity meter, connection to a PC, storage charging function. Of all this, I only received balancing charging, and even that with a significant limitation and a very long operating time. The fake is not even worth the $19 spent on it.

I don’t really care about the fact that instead of a well-known microcontroller, some little-known other one is installed, as long as it works, but alas, this is not the case. It is possible that the alternative microcontroller has worse characteristics, and it is impossible to write a program similar to the original one for it, but it is more likely that a specific programmer is to blame. In general, the replacement looks more interesting, at least with the greater accuracy of the ADC (12 bits versus 10 for the ATmega32 of the original), but there is no exact data yet, the datasheet could not be found even on the manufacturer’s website, the data on the ADC was taken from the general description of the M051 series.

Of all the functions, only charging with balancing turned out to be really useful, but only if you charge the batteries up to 4.1 V (select the lithium type LiIo in the settings). I will charge it. For this battery, I first planned to buy a separate 1 A balancing charger, which would have cost me about $12. This charger, taking into account a partial refund during a dispute with the seller, cost me even less, and the charging current here can be up to 3.3 A (for battery assemblies with lower voltage up to 5 A).

If you want to try to find an original charger, try searching for the key phrases “genuine imax b6” and “original imax b6”. After purchase, it is better to open it and make sure that there is a microcontroller from Atmel inside, and you need to check not only the markings, they can be interrupted, but also the pinout of the chip. (I’m not sure that all originals from all years of production will have the same microcontroller) It’s better to buy on eBay, where they fight counterfeits harshly. I took an item on AliExpress with a large number of orders and a lot of positive reviews, and I bought it.

Update dated October 5, 2015

In one of the photos above you can see that the power and balancing connectors are a little crooked. If this does not cause problems with the power ones, then the balancing ones can accidentally be inserted not completely, so I decided to correct them. The balancing connectors are soldered to a separate small board, which is inserted into the main slot and soldered to it there. To correct the position of the connectors, I had to forcefully pull the board out of the slot, which reduced the soldering area on the back side, which somewhat reduced the strength of the connection. The very principle of such fixation seems very unreliable; the soldering fastening can be damaged if the connectors are used frequently.

I also had to completely remove the main board from the case, and a couple more problems immediately appeared. Unlike the top side, the back of the board is all stained with flux residues; it had to be washed. The power transistors are pressed against the body through a gasket and a layer of thermal paste. The problem is that the thermal paste was already all dry, so I had to clean it all off and lubricate it again.

The protective film was not removed from the screen during assembly. It looks very clumsy (see photo above), since it is glued not to the screen itself, but to its frame. I removed this film and put a new one, but only on the surface of the screen. The film will definitely not be superfluous here, since the device can be used in field conditions.

I charge the lithium-polymer assembly with a maximum voltage of 4.2 V with balancing to 4.1 V (Li-Ion mode). This way the process is completed quite quickly, although the battery is not fully charged. I also charge my other batteries to 4.1 V. Due to the relatively high charging current, this charger does this faster than older ones that try to push the battery to 4.25 V, regardless of its capabilities.

I checked the operation on a lead-acid car battery. Charging behavior is about as inadequate as in the case of nickel. For example, I was charging a half-discharged battery, the final voltage showed something like 13.8 V. For my battery, such a voltage will not even cause the electrolyte to boil. Having connected the almost charged battery, the charger showed that it would bring the battery up to 14.5 V (I don’t remember exactly). It’s not critical, but you already have to keep an eye on the bubbles. Then I connected the charger again, and the final voltage rose to 15.5 V (approximately), the current voltage also increased, to approximately 14.5 V (again, I don’t remember exactly), which led to the electrolyte boiling. In general, you can charge, but only under supervision, as is the case with any regular car charging, there are no advantages here. The maximum charge current is 4.2 A, which is not enough.

This does not mean homemade, but ready-made Chinese. On the one hand, there are quite a few outlet adapters on sale with a compartment for 4 AA or AAA elements. On the other hand, lithium batteries are being used more and more in gadgets and electronic toys, so you need to choose with an eye to the future. In general, after much thought, I settled on the universal programmable memory imax b6. There are original ones on sale, and there are Chinese copies. It’s hard to say how they differ, but my colleague bought a copy and has been successfully running it for almost a year now. The choice has been made.

Features of the imax b6 charger

• Controlled by a microprocessor
• Separate balancing of each bank
• Compatible with Li-ion, LiPo and LiFe batteries
• Compatible with Ni-Cd, Pb and NiMH batteries
• Wide charging current range
• Charge/discharge to battery storage voltage
• Charging time limit function
• Input voltage monitoring
• Storing up to 5 sets of battery parameters in memory
• Storing the battery commissioning date and service life.

Specifications

• Input voltage: 11~18v
• Maximum charging power: 60W
• Charge current range: 0.1~6.0A
• Discharge current range: 0.1~2.0A
• Ni-MH/NiCd: 1~15 cans
• Li-ion/LiPo: 1~6 cans
• Pb battery voltage: 2~20v
• Dimensions: 133x87x33mm
• Price: about 1500 rub.

This charger is not suitable for those who are used to sticking it in, pressing it, and then removing the batteries after several hours. Firstly, it requires an additional adapter (mains power supply) for 12-18 volts, and secondly, it does not have a battery connection compartment - only two crocodiles, which we hook to where needed. Therefore, to work with conventional 1.5 V AA batteries, you need to get a cassette box. But this is not a problem - they cost pennies.

Although the kit includes several other different cords with connectors - maybe someday they will be needed.

Instructions for use

We connect the power, the screen with the inscription SkyRc Imax-B6 immediately lights up. There is no on/off button for the device. After this we get to the main menu.

You can navigate through it using the "Stop" and " buttons.<". В главном меню находятся: выбор программы зарядки в зависимости от типа аккумулятора, меню настроек. Вот алгоритм управления:

As well as points for saving and loading user settings. You can select an item by pressing "Enter". Here, for example, is the Li-Ion charge menu item:

By pressing "Enter" again, we go to the parameter editing mode. The parameter being changed flashes at this time. You can change the maximum current and voltage. It's the same with nickel-cadmium.

Protection works at every stage. Charging will not start if: the battery polarity is reversed, the voltage is too low or too high, the voltage does not match the type of battery or the number of cells, etc.

It is possible to set the discharge and charge current, as well as the number of these cycles - this is a procedure for restoring tired batteries. After setting all the parameters, you can start charging by long pressing “Enter”.

Example of designation on the screen: NiCd - nickel battery. 0.1 A is the current charge current, 3.02 V is the current voltage, DHG is short for Discharging, charge. 000:35 - time in minutes and seconds from the start of the program, 00000 - “capacity” in milliamp-hours “poured” into the battery during charging, or received from the battery during discharge. Naturally, the second number will be smaller, and this is what you should be guided by when measuring the battery capacity. Description of the process in the photo below.

For more details, read the instructions supplied with the device or download this Russian-language manual.

A few more words about BP. In principle, any power supply will do, not necessarily a 5-amp one (unless, of course, you need to charge something very powerful). For most batteries, the charging current rarely exceeds 0.5 A, so the first 12 V, 1 A unit that came to hand turned out to be the last - the imax b6 has been working with it for the second month.

Diagram and details

What about without disassembly? Like a real radio amateur, the first thing I did was unscrew a few side screws and look at the diagram. Here you can see a buzzer, a standard LCD display, several planar microcircuits and other random items. I have no doubt that some craftsmen will reproduce this device without any problems, but for most it will be justified to buy a ready-made one, especially since 30 dollars is not that much money - buying parts will already eat up half the amount.

Charging day

Immediately after the purchase, I arranged a charging day for myself - I collected all the batteries, of which I had accumulated a couple of dozen, and assigned 3-5 discharge-charge cycles and began to restore them. At the end of the cycle, a melodic sound signal is heard, and the approximate battery capacity is shown on the screen. It makes sense to copy it with a marker onto the battery housings so that in the future you will know what you can get from them.

Yes, it won’t even undertake to charge bad banks - feel free to throw them away. In general, a cool and convenient thing, after which you will no longer want to use conventional chargers! Bye everyone, the material was prepared specifically for the site Radio circuits .

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