I greet everyone who looked at the light. The review will focus on, as you probably already guessed, a competent alteration of the power supply of a radio-controlled car from nickel to lithium, taking into account all the previous crutches. This method is quite simple and quite budgetary, so anyone interested, you are welcome under cat ...
Upd, added several options for protecting the electronics of the RU model

The previous version of the limit aka backstory:

A few months ago I posted a little about the rework of the RU model (cop machine) based on the MT3608 step-up converter, TP4056 charging board with built-in protection and one Li-Ion battery. The bottom line was simple: the voltage was raised from the battery using the MT3608 converter to the required level, and the "popular" TP4056 handkerchief allowed charging the battery from any source with USB output. The wiring diagram was very simple:


When soldered and fixed with hot melt, it looked like this:


Charging the car was simple and convenient:


But in the process of operation, some shortcomings came to light, namely, when the current consumption of the switchgear was more than 1.5A, the protection worked out and the power was briefly lost. This mainly concerned serious RU models with more or less powerful engines. In my version, the machine consumed about 0.9A at maximum and there were no malfunctions. But with a significant decrease in the battery voltage, I had exactly the same situation - at the peak of the load, the machine jerked. Since the machine was used infrequently, the capacity of the built-in battery was decent, and it was banal too lazy to deal with this topic, then everything was left as it is. At the first symptoms of "twitching", the machine was simply put on charge. More recently, free time appeared and another method of rework was invented. In terms of costs, it is slightly more expensive than the previous one, but it has some advantages, which will be discussed below.

To begin with, let me remind you of the advantages of lithium power supplies (Li-Ion / Li-Pol) over nickel (NiCd). In our case, the comparison is only with NiCd, because only they can give a high current. For example, let's compare the original car battery and the variant after the alteration:
- high energy density. The machine contains one cadmium battery 5S 6V 700mah, the stored energy is 6 * 0.7 \u003d 4.2Wh, and in the version after the alteration there will be two lithium batteries 18650 3.7V 3350mah connected in series. The stored energy will be equal to 7.4 * 3.35 \u003d 24.8Wh, respectively. As we can see, the stored energy is several times higher, which allows the machine to work much longer. If we compare face to face one NiCd and one Li-Ion / Li-Pol battery, the difference is simply huge.
- no memory effect, i.e. you can charge them at any time without waiting for a full discharge
- smaller dimensions with the same parameters with NiCd (in comparison with the assembly of nickel)
- fast charging time (not afraid of high charging currents) and clear indication
- low self-discharge
The only drawbacks of Li-Ion are:
- low frost resistance of batteries (they are afraid of negative temperatures)
- balancing of cans is required when charging (in the case of 2S or more) and protection against overdischarge

As you can see, the advantages of lithium are obvious, especially for home use, so there is a sense of rework.

Briefly about the converted RU model:

So take two

I did not step on the same rake, so I immediately decided on a diagram of two Li-Ion batteries connected in series using a 2S BMS protection board. The main disadvantages of this circuit are the uneven discharge of batteries, depending on their condition and the low prevalence of chargers for such a connection, as well as possible damage to the electronics of the RU model from an overestimated supply voltage. The BMS fee is required here, because protects batteries from overdischarge, so I recommend not to neglect it. But the situation with the charge to this day has improved somewhat. There are two simple budgetary ways to charge a 2S lithium battery:
1) Wild collective farm in the form of two TP4056 charge kerchiefs for each battery and two power adapters / power supplies for charging them. If the farm has two more or less normal adapters with an output of 0.5-1A, then the option is quite suitable. You will need to spend a little on TP4056 scarves, but again, charging will not be very convenient. If there are no network adapters / power supplies available, then, as they say, the skin of the dressing is not worth it and it is better to abandon this method
2) We use specialized memory for 2S-3S assemblies. There are plenty of them on the sites now, they cost around $ 5. In this case, it can be useful in the future, for example, for the simultaneous charging of various Li-Ion / Li-Pol batteries, for altering a power tool, etc.

Required components for revision:

As you can see, no expensive components are required:


The main brain of the system is the 2S BMS protection board XWS8232FR4, which costs about one dollar:


It is not difficult to guess that it is based on the same Seiko S8232U controller and power mosfet:


The most expensive of all the components is the 2S-3S ImaxRC B3 charger, which costs about $ 5:


It is a copy of the famous SkyRC e3 charger, but with more modest charging characteristics:


I have the original and another option, but on 4S, which I will talk about and compare face to face in future articles. By the way, there are a lot of these copies, at least I saw 3 things, but in my opinion, the circuitry is similar there.
The next important link is the batteries. I used Panasonic NCR18650BF Li-Ion batteries from Xiaomi PB 10000mah, 3350mah capacity each:


In this implementation, it is desirable to use modern high-capacity banks with an underestimated discharge threshold of 2.5V. There are a lot of models (high-capacity Sanyo / Panasonic / Samsung / LG banks), everything above 2800mah usually comes with a 2.5V discharge threshold. Folk Sanyo / Samsung 2600mah are not very suitable for this headscarf. have a slightly "overestimated" discharge threshold in the region of 2.75V. A slight difficulty is soldering the supply wires to the battery contacts. If you have no desire to bother with soldering, then you can attach a single / double-slot holder / holder for a 18650 f / f, for example.
To charge the future RU, the model will need one USB connector (male and female), as well as a 3-pin connector for connecting to the charger. It is often found in CPU coolers. I found these components in my store, the USB "dad" bit off the worst twisted charging cable:


All these components cost a penny and may be found in a closet.

Testing scarves:

A few words about the protection headscarf. The connection is very simple, the only difficulty is that its dimensions are small, so the wires must be soldered carefully. The connection diagram is as follows:


Let me explain briefly: the connections that are responsible for the operation of the board are in green, and the connections to the charger are in blue. It is advisable to solder the outputs from the charger to the battery contacts, in order to avoid additional losses, but if it is impossible to do this, the option of connecting to the protection board will do.
This scarf is the simplest one, so if you need an analogue, then look for it on Internet sites under the name "2S bms" or "2S Li-ion Lithium Battery Protection Board":


The most important thing for me in the scarf was the threshold for disconnecting the battery. For this I made a small stand. Here, the power supply unit Gophert CPS-3010 is used as one battery, for which I recently made a regular Li-Ion battery. By changing the voltage on the regulated power supply, you can find out the exact threshold of the scarf. Second battery voltage 3.8V:


If we set the output voltage of 4.2V on the power supply, then the output will be 8V (4.2V + 3.8V), which can be seen on the left screen. The multimeter here measures the output voltage from the 2S BMS board. If you set 3.8V on the power supply, then the output will be 7.6V (right screen):


Everything works normally. Now we look at the protection operation threshold. When 2.41V is installed, the scarf continues to work and at the output the total voltage from both cans (left screen), but as soon as we lower it to 2.4V, the protection is triggered and the scarf turns off the output voltage (right screen):


In total, the protection response threshold for any of the two batteries is 2.4V. That is why I wrote that "folk" batteries at 2600mah are not very suitable here. There is a blocking, i.e. the scarf does not "recover" itself. Unfortunately, I did not measure the protection current, but it should be around 3A.

Direct assembly:

When all the necessary components are available, you can proceed. The first step is to assemble a 2S Li-Ion battery assembly. This is an option for those who do not like the option with holders for 18650 cans, for example, due to the size. To do this, we glue two strips of electrical tape on each battery. This is necessary to hedge against short circuit protection, since the thermal shrinkage of the batteries is quite thin and can be damaged. Considering the fact that RC models are usually subject to shock, shaking, etc. - there will be no unnecessary reinsurance. After that, we connect the batteries with strips to each other and wrap them with a layer of electrical tape (you can use other insulators):


Then you can start soldering the contacts. I have already described how to do this several times, so I will not repeat myself (there will be a detailed video in the review of the screwdriver alteration). Soldering does not bring much harm, the main thing is not to hold the tip of the soldering iron for a long time, well, and to use an active flux, such as soldering or phosphoric acid. After it, do not forget to wipe the soldering area with alcohol!
Next, we take the wire, if desired, we clean it as in the photo on the left (you can do it with two wires) and solder together the connection of the batteries and the entrance of the scarves. It should look something like this:


I will not dwell here in detail, since there can be many options. The option is closer to me when the batteries and the protection scarf are together, since the losses in the wires are minimal. Next, we solder the remaining wiring according to the same scheme (see above):


This completes the assembly of the 2S battery, but it still needs to be charged somehow. To do this, we will use a ready-made inexpensive charger, which is an analogue of three linear charging controllers with independent power supply for each arm. Since the charger can charge both 2S and 3S assemblies (optimal for a shura), it can be useful in the future not only for charging RU models. To charge the 2S assembly, we need the left connector:


To confirm polarity measurements:


At idle, the voltage jumps a little, but when charging the battery, the limit is exactly 4.2V per bank.
For a convenient connection to the charger, I soldered the adapter from the USB "male" connector and the three-pin connector, insulated the soldering point with heat shrinkage:


Since the wiring is frail, I wrapped everything with electrical tape to increase the mechanical strength:


The USB female connector is for RC model. To do this, we make a corresponding hole and insert the USB connector all the way (at the end, the connector has stops):


For a more reliable fixation, we solder three wires of sufficient length and fix with hot melt glue:


Next, one of the important stages is the connection of the resulting 2S battery assembly with the charger contacts according to the diagram from the "Testing the scarf" section. Here we follow the proverb - measure seven times, cut once. We check the pinout of all connectors and solder the wires. I will not confuse you with my "snot", because they will all be different. Once again, we check and connect everything. If all is well, we put the whole household and assemble the RU model. We leave the battery in the battery compartment. To prevent the battery from flopping, put a bubble or isolon next to it. I got it like this:


We open the car door and connect the charger. If the batteries are discharged, the charger starts charging, while the indicators are red. If there is an imbalance and one of the two cans is charged faster, its charge stops and the indicator changes to green (right screen):


As soon as both batteries are charged, all indicators will be green:


From operating experience, I can say the following that this budget charging is not bad, the charge current per shoulder is about 900ma (at 2S), plus it is possible to charge both 2S and 3S assemblies. For more detailed characteristics and comparisons with other models, see future reviews.
The implementation of charging the car turned out to be the same as in the previous version. To charge, we move the door and connect it, you do not need to disassemble anything:


Now about the consumed currents.

In standby mode, the machine's board eats 56ma:


Normal driving - around 300ma:


Maximum current consumption is about 900ma:


We launch - everything flies. This option is not at all more complicated than the previous one, but the characteristics of the RU model will increase. The only danger is whether the electronics of the toy can handle the 8.4V.
That's all for me ...

Appendix 1:

Since not all RU models are designed for high supply voltage, if desired, you can reduce the voltage with an excellent step-down DC-DC converter:


The only remark is that after adjustment, the trimmer must be fixed with varnish or glue. This converter has a compact size, high efficiency and a decent operating current of about 3A. Other converter options are also available on site. We google "DC-DC step down".

The second option, as correctly noted in the comments, is to limit the operating current with a simple current-limiting resistor. This is to protect the motors from excessive current. Since it seems to work fine for me, I did not redo anything. For those who need it, I suggest a small resistor calculation for my version. To do this, you need to decide on the denominations:
- U (pit) - supply voltage from the assembly. In our case, let it be 8V (two batteries)
- U (electr) - power supply voltage of the machine electronics (RU model). In our case, the standard was 6V (5 consecutive NiCd batteries)
- U (extinguishing) - the difference between the "new" power supply and the "standard" before rework
- I (slave) - limiting current, i.e. maximum for a typewriter. In my version, the machine eats 0.9A at the maximum. To protect the engines, you can set, say, 0.5A
- R (damping) - resistance of the current-limiting resistor (see calculation)
- P (damping) - resistor power (see calculation)

So, we calculate everything according to Ohm's law: I \u003d U / R
U (extinguishing) \u003d U (pit) - U (electr) \u003d 8 - 6 \u003d 2V
R (extinguishing) \u003d U (extinguishing) / I (slave) \u003d 2 / 0.5 \u003d 4 Ohm
P (extinguishing) \u003d I (slave) * I (slave) * R (extinguishing) \u003d 0.5 * 0.5 * 4 \u003d 1 W

Based on the calculations, we need a 4 Ohm resistor with a power of at least 1 W. It is better to take with a margin of 5 W so that it does not overheat:

An overview of a brisk r / y machine with disproportionate control and a story about its transfer to power from a 1x18650 battery. More details ...

Has long been eyeing the monitored machine. First of all, I was attracted by a more or less decent size, because I am wary of tiny cars for their health when they fall into the hands of children. I also wanted to try the pistol-type control panel (or as it is also called professionally - "equipment"). I somehow did not bother with proportional-disproportionate control, because I am not spoiled, and now, finally, I decided to order this machine until the dollar rate rose to today's heights.
I will not talk about the relationship of mail to parcels, everything is visible in the photo. After being removed from the mail package, I somehow thought, "that's it ... the end of the machine," but no, it carried ...

Some pictures of pictures from the box

The machine with all the accessories was securely "imprinted" into the cardboard

And in addition to the standard wires, it is additionally tightened with special screws with a wide head

Contents of the box: the actual sports car, remote control with antenna, battery, battery charging cable and instructions (not shown in the photo)

The miracle did not happen with the battery and it turned out to be a "whole" 400 mAh with an output voltage of 3.6 volts

The battery charging cable allows you to charge both from the USB port of a computer and from a wall charger with a corresponding connector. I charged with a phone charger. There is a microcircuit on the cable from the port side, apparently controlling the charging process. During charging, a red LED lights up inside the translucent case, after charging is complete, it goes out.

The remote has small (versus professional) dimensions and a screw-in metal telescopic antenna

Powered by 2 AA cells

The length of the antenna in combat condition is 52 cm

No "on / off" is provided on the remote control - put the batteries in and go.
Remote control modes:
- pull the trigger - go forward
- pull the trigger - go back
- wheel forward - turn right
- wheel back - turn left
The trigger and wheel are spring-loaded and automatically return to the middle (non-working) position; a red LED is provided on the remote to indicate signal transmission

Finally, we turn to the typewriter. According to the racing class, I would class it as a buggy.

Large wheels, shock absorbers, cockpit fairing, spoiler - everything speaks of the explosive nature of this car

True, round headlights spoil the picture a little and refer us to the class of retro cars

The battery compartment is located at the bottom

The compartment lid is fixed with such a latch, but for special cases you can additionally play it safe and screw the screw into a special place on the lid

The compartment has a wiring with a connector for connecting the battery

It is not entirely clear why the size of the battery compartment is decently larger than the size of the battery - apparently there is some sacred idea ...

Although the shock absorbers are not oil, the springs are working, the front ones, by the way, are a little softer than the rear ones

Rubber - summer soft front

On the back there is a winter stud, also soft

The headlights in this car are not fake at all, but quite workable - they glow when driving, everything is as in the rules, both day and night

Superficial disassembly of the car showed that under the plastic body there is a small board through which all components and assemblies are connected.

Instead of the national domestic blue electrical tape, Chinese designers used a high-tech innovative adhesive tape made of nanopaper to tighten the accumulation of wires

At the site of the intended placement of the racer's head, an antenna is glued, again presumably

In the assembled state, there is practically no space left under the plastic, this is what I hoped before disassembly that it would be possible to shove an alternative energy source here, but no ...

Several photos of the race in street conditions

The size of the remote control for a child of 7 years old turned out to be just right - and not small and not large

Race in the arms of the same child

The above photos on the street were taken as part of the first test drive. The car seemed quite fast, but only when driving on a flat surface such as asphalt, tiles, etc. For driving on gravel or grass "health" was not enough ...

I attach a small video of the rides (at the end - a short episode through the eyes of a rider :)

Before the test drive, the battery was pre-planted and charged again. On a full charge, the car skated about 20-25 minutes, which, frankly, was a surprise for me - I expected that it would be enough for 10-15 minutes (according to the experience of a similar machine from offline)
Expecting that in the future the standard battery will spend most of its time on charging, even at the ordering stage, an idea arose about the possible conversion of a car to a battery with a larger capacity, for example, type 18650.
Upon receipt of the car, the desire to carry out what was conceived only intensified against the background of the fact that the standard battery produces 3.6 volts versus 3.7 for the 18650, i.e. no alterations for lowering / raising the voltage were required, it was only necessary to find a suitable place to place the "can". In the end, the idea was fully implemented and the result was achieved; in time, the whole process took about an hour (if you do not rush).
Anyone who is interested in alterations ala "crazy hands" with elements of hardcore - please under the cut

Conversion of a car to a lithium battery type 18650

So, an unprotected Samsung battery from an old laptop battery was chosen as the new power source for the race. Its capacity is not known to me, but I think that it is more than 2000 mAh.

The standard battery compartment was chosen as the location for the "can". Unfortunately, the width of the compartment turned out to be only 2-3 mm less than the length of the 18650, so we had to consider the possibility of diagonal placement.

In this position, if necessary, you can shove in a protected 18650, but it seemed to me that there would not be enough space for placing the contact pads. It would seem that everything turns out beautifully and cool, but as always, a "small nuance" was drawn - the thickness of the 18650 turned out to be slightly more than the depth of the compartment, as a result of which it was impossible to close the lid even with effort

The simplest solution would be to cut the required hole in the compartment lid and thereby bring the excess thickness of the battery out, but knowing the fear of lithium to any blows, I decided not to risk it and go a more complicated but less dangerous way - to go deeper into the inner underbody space.
With the help of improvised tools, the required size window was cut, while the control board located above this place was previously unscrewed to avoid damage

The distance to the board elements located above the battery was about 5 mm.
It turned out, of course, not very aesthetically pleasing, but the result was achieved, the battery shifted a little inward and ceased to rise above the battery compartment, allowing itself to be closed with a lid.

It was planned that the battery will be charged with a desktop charger, so it was necessary to implement some kind of a contact pad for inserting a battery into it.
As always, the necessary raw materials were found among the "necessary spare parts", which was the lower part of the outdated musical clock

To fix the battery and compensate for small distances at the corners of the compartment, two corners were cut out of the packaging "foam" from the router

To which the contact pads were then glued

Contact wiring was brought out into the "underbody space", and corners with contacts were glued to the appropriate places in the compartment

The battery fits perfectly - nothing dangles and does not fall out, the contacts are laid down as planned

In conclusion, the wiring from the contacts was soldered in the same places as the wiring of the standard battery connector

Oddly enough, but the whole structure worked the first time, which is extremely rare or almost never :)
The new battery was fully charged and the machine was tested for an hour until it just got bored. After all this, there were no signs of battery discharge. Also, for several days before writing this review, the machine was driving 20 minutes a day and until it was discharged, so I am completely satisfied with the result, in addition, I managed to retain the possibility of using a regular battery - the connector remained in the battery compartment ...
As for the running characteristics, though not significantly, they have increased. I checked it on gravel - if on a regular battery the machine did not drive on it at all, then on a new one it drives - worse than on asphalt, of course, but it does.

In conclusion, I'll tell you about the machine as a whole.
Drives briskly, in the dark with headlights it turns out quite interesting.
The control is not proportional, i.e. regardless of the angle of rotation of the control wheel of the control panel, the wheels of the machine turn to the extreme position.
When the wheels are turned, the power of the machine decreases, because part of the energy is spent on holding the wheels, if you release the control wheel, the wheels of the car return to the straight-line direction automatically.
The front and rear bumpers are quite solid and protect the car well from frontal impacts at full speed, but you need to try not to hit the front wheels, because the swing mechanism is practically unprotected.
The remote control antenna, although metal, requires careful handling.
The radius of the "defeat" of the console with the extended antenna is approximately 40-45 meters.
There is no need to talk about the super-reliability of the mechanisms, since all of them are mostly made of plastic and will begin to wear out and rotate over time, but this is a direct consequence of the cost and orientation towards children - they will still break :)

Thanks for attention.

I plan to buy +22 Add to favourites Review liked +46 +82

Good afternoon!
I bought a r / y machine for my child But I ran into one problem. Good batteries cost decently, and given that there are 5 of them in a car, their replacement with an active game is comparable to the cost of refueling a real car. It was decided to find a suitable Li-Ion or Li-Po battery for installation in the battery compartment of the car.

I already had a charger for such batteries (IMAX B6) and there will be no problems with charging. After poking around on Aliexpress, I stopped at the Dualsky XP08002ECO, its size was ideal for installation in a typewriter. I only had to make two simple improvements. The first is to bite out the rather tall partitions between the AA elements. The second is to solder the tail with the JST connector to connect the Li-Po battery. I ordered a tail with a JST connector.
Photo cars


Battery compartment with batteries (Li-Po tail is already soldered)


Battery compartment with bitten baffles


Li-Po connection using a temporary tail (no standard connector, there is a possibility of polarity reversal)


Li-Po rechargeable battery in battery compartment


The machine works great.
Battery capacity is as stated.
I bought two batteries at once for quick replacement during a walk.
The battery pack contained 4 stickers with the logo of the battery manufacturer. The child did not want to stick them on a new typewriter. I pasted two on an old Toyota Corolla.


Until I put the standard tail with the original JST connector, I will change the battery myself, otherwise the child may confuse the polarity. When discharged to 7V, this machine becomes sluggish and therefore the likelihood of over-discharge of the battery is small.
I do not give technical characteristics, they are on the product page. The operating time of the machine from the battery too. It will depend both on the implementation of the electronics of a particular r / y model, and on the underlying surface on which you drive. Yes, and the weather has not been happy lately, but this model is too big for a home.

This is my first review, don't kick too much. I welcome criticism.
The product was bought for your own money.

Radio-controlled models (cars, ships, aircraft or military equipment) need a source of electricity - a battery. If your model is equipped with an electric motor, you will need a power battery, if your model is powered by an internal combustion engine, you will still need a battery to power the radio, servos, gyroscope or other electronics.

For radio-controlled models, nickel-cadmium (NiCd), nickel-metal hydride (NiMh), lithium-polymer (LiPo), lithium-iron-phosphate (LiFePO4) batteries are used.

Main characteristics of batteries:

1.Capacity - measured in milliampere-hours, (mAh). The capacity of on-board batteries for equipment and servos can range from 200-300 mAh to 2000 mAh. Power batteries for electric motors can have a capacity of over 5000 mAh.

2. Cell voltage - it depends on the type of battery, for NiCd and NiMh it is 1.2 V. LiPo cells have a voltage of 3.6 V.

3. Battery voltage - total voltage of cells (cells in batteries are connected in series). Is there a linear relationship? The higher the output voltage of the battery, the higher the maximum current that the battery can deliver.

4. Battery mass - depends on the type of battery and its capacity. One of the most important indicators of batteries is the capacity to mass ratio (specific capacity). The higher this indicator, the more significant the battery power reserve.

5. Current output - the ability of a storage battery to deliver a certain current under load. This value has a designation like "* C", where * is a numerical value, multiplying it by the battery capacity, we get the current that the battery can give. Power accumulators for radio-controlled models can have a current output of 10C or more.

6. Internal resistance - its value determines the current output of the battery. The lower its value, the higher the current output.

Nickel-cadmium batteries

These batteries are often installed on radio-controlled models as power (running) ones. NiCd battery cells have a cylindrical shape, for which they were called "banks". Nickel-cadmium batteries are not cheap, but they also "work out" their cost: such batteries are capable of delivering significant currents for a long time, have a long service life, and a significant number of cycles (charge-discharge).

Metal hydride batteries

NiMh batteries have similar shape and characteristics to nickel-cadmium batteries, but have more "elastic" performance and lower cost. Power NiMh batteries can last from 500 to 1000 charge-discharge cycles and from three to five years. With such batteries, the so-called "memory effect" is less pronounced than with NiCd batteries.

Lithium polymer batteries

LiPo batteries are a fairly recent development in the field of power supplies. Externally, these are rectangular plates with a nominal voltage of each element of 3.6 V (when fully charged - 4.2 V).

Their capacity can be quite high (an indicator with a specific capacity of almost three times that of NiMh batteries). LiPo-batteries are more efficient, they are successfully used in modeling. Such batteries require careful and careful handling.

Lithium Iron Phosphate Batteries

This is the "youngest" type of storage battery used in modeling. Such batteries have a capacity comparable to LiPo batteries, while at the same time they are unpretentious and reliable batteries like NiCd. The cost of such batteries is high and they are not widely used in modeling.

When choosing a battery for a radio-controlled model, one should take into account its capacity (the capacity should be enough to ensure the full operation of the model for a certain time), voltage, dimensions, the ability to charge an existing charger. The shape of the battery is also important: it must be suitable for your model. The shape is determined by the layout of the battery cells.

Battery charging

Rechargeable batteries for radio controlled models must be charged. To do this, there are various chargers: from the simplest, designed for "your" type and capacity of the battery, to universal chargers that work with all types of batteries and provide any modes of charge, discharge, balancing each battery element.

Simple chargers are not expensive, but the "quality" of the charge they provide is not the highest.

Simply put, these are “fixed” charges for batteries of a certain type and capacity. Such chargers do not adapt to the changing characteristics of used batteries and are not recommended for use with batteries of different types and capacities. And increasing the number of charges, having its own charger for each battery, is not the best move. Therefore, sooner or later modellers come to the need to purchase high-quality multifunctional charging, for example or ... Of course, such a Z / U costs significant funds, but this is a reasonable and even necessary investment.

The main point for the modeler to understand is that each battery lasts longer and more efficiently when it is provided with full charge and discharge cycles.

Recently, all inexpensive radio-controlled models began to be equipped with Ni-Cd batteries (nickel-cadmium batteries), or rather, assemblies of these batteries. Batteries of this type have a low market value and there are a number of reasons for this.

Relatively simple and cheap manufacturing technology

Have a memory effect

Small number of recharges

Small specific capacity

Sooner or later, your favorite toy stops turning on, the battery becomes unusable, and the question arises where to find a new one. But where to find the size you need, and most importantly with the same type of battery connector ?!

You don't have to look for anything if you have a soldering iron, a pair of wires, a heat shrink tubing, and 30 minutes of free time.

So, let's say you have a toy powered by a 7.2 V Ni-Mh or Ni-Cd rechargeable battery, 400 ma / h. Naturally, we want not only to bring the toy back to life, but also to extend the playing time on one charge. Therefore, we will increase the capacity of new batteries several times!

By turning the old battery in your hands and cutting its shell, you can easily make sure that it is assembled from conventional AA-grade AA batteries by the serial connection method.

Therefore, we need, in our example, this:

6 rechargeable batteries Ni-Mh class AA, each battery 1.2V, respectively, to obtain 7.2V \u003d 1.2V * 6, Of the same capacity!

· Heat-shrink tubing

Soldering equipment: soldering iron, flux, solder

File / skin

Copper stranded wire about

You may have noticed that the batteries in the old battery are not soldered. And this was not done in vain, because with strong heating it is possible to damage the battery, but, as they say, "everything is good in moderation." We will connect the batteries by soldering, but using a certain technology.

In order for the solder to quickly "stick" to the contact surface of the battery, first clean the surface with a file. When processing with a file, irregularities and scratches are also created that will create conditions for reliable contact.

Personally, I use ordinary rosin or soldering fat as a flux, and ordinary tin-lead solder, the temperature of the soldering iron is 450 degrees.

We will tin the contact pad. If the solder does not "stick" it is not necessary to heat up the battery pad for a long time, this can lead to its failure. In this case, add flux and solder and try again.

I do not recommend using insulated wires to connect the battery, because they will greatly change the size of the battery, in some cases this is a very important factor. Therefore, I usually strip the insulation and make a kind of flat connecting plates by tinning the bare wire.

Since we tinned the contact pads of the battery in advance, it will not be difficult for us to solder the connecting plate.

We connect the battery in series, that is, "+ " one battery is connected to "- " another, and so on. The positive contact of the first and the negative contact of the latter, respectively, will give a total output voltage equal to 7.2 Volts.

Having connected all the necessary wires, including the charging connector, we put the assembly in a heat-shrinkable tube and heat it (you can use a regular hair dryer).

Let's summarize. You were the owner of a weak battery with a supply voltage of 7.2V, a capacity of 400ma / h, which was based on 6 rechargeable Ni-Cd batteries. Taking the connector from the old "dead" battery and doing all the work described above, we got: a battery with a capacity of 1800 ma / h, supplying voltage 7.2 volts, Ni-Mh without memory effect.

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