iCharger 206B - The 300W lipo charger that fits in your shirt pocket

Review last updated: May 10th, 2011
Thanks to David Gray over at ProgressiveRC for sending me an iCharger 206B to use, review and show off.

We live in a great time. Every couple months we see a new, more powerful lipo and for less money than the previous model! This has changed all of electric rc. It has not only made for fantastically powerful electric models but it has also allowed the average hobbyist to gain access to large electric models, something totally unforeseen by most.

Ok so lots of normal guys are flying big electric models now but many have discovered a problem. They have the big models, they have the big packs but their old charger is just too limited for their needs. These pilots need a powerful charger to support their new big models and it needs to be affordable. Well we are in luck, as there are iChargers to be had and they are not only some of the most powerful chargers on the market but they are also well priced and very well featured.

The iCharger line consists of 5 chargers as of the writing of this review and the 206B can be considered a newer, more powerful version of one of the earliest iChargers, the 106B. In short the 206B is likely to be the favorite in the lin-up for most hobbyists.

What makes iChargers special among chargers
The iCharger line of chargers is very special when compared to other chargers on the market. Below are just some of the things that make the iChargers stand out among all the other chargers out there.

Efficiency of 90%+

The iChargers are some of the most efficient chargers sold today. Why would a charger's efficiency matter? Let me give you two examples where this increased efficiency is useful.

Most times efficiency losses result in energy being lost to heat. Since the iChargers are so efficient, they do not need large heat sinks to dissipate heat and this allows them to be housed in very small and tidy enclosures. But even though iChargers are very small, they still run cooler than most other chargers.

Since less energy is wasted by the charger, smaller power supplies are needed to supply the iChargers. The difference may only be 10% but that can make a valuable difference. For example this can be very helpful when using a generator to charge, as the power losses are additive. Having the charger use 10% less means the power supply will not only need to output 10% less but then its own losses will be lowered.

Simple and well designed
When you take an iCharger out of the box for the first time you will not only be struck by how small it is but you will also notice that it is also a simple rectangular metal box, and not some space ship of an enclosure like some chargers. This makes the iChargers very easy to pack and store. The screen is recessed to keep it safe and the buttons are actual buttons. The input lead is on the left side and all the outputs are on the right side, just like they should be. This arrangement makes lots of sense and helps keep things neat and clean. Also the 6s chargers have 2s-6s connectors built right into the side to make connections even simpler and cleaner.

iChargers are designed to use JST-XH for balance connectors. These are not only the most popular connector in the battery world but they are also the most straight forward in terms of wiring layout. This makes it very easy to buy/make special adapters for advanced charging methods like serial and parallel charging.

Manufacturer support and firmware updates
The manufacturer of iChargers is a company named Junsi. Junsi participates on RCGroups on a regular bases to help solve problems as well as get feedback from owners. This collaboration allows Junsi to tailor the iChargers to the needs and wants of the owners. For example over the past few firmware updates, many new features have been added. This includes the addition of cell count auto-detection in lithium balance charge mode and the ability to adjust settings during charge cycles. In the near future  regenerative discharging should be added to the entire iCharger line. I have yet to find another company puts as much effort into making their product match the needs of the owners as Junsi does.

First impressions
I have owned an iCharger for almost 2 years now so I was not too surprised by the size and feel of the 206B. I have a 208B and with the exception of the lack of balance ports on the side, the 206B simply looks like its little brother. When most people first see a 206B (or 106B+), they are blown away by just how small iChargers are. They are more familiar with other large units and can't believe that the 300W 206B will literally fit in their shirt pocket.

The tiny 206B!

The 206B ships with everything you need to use it. It comes with a USB cable for updating it and logging charges, it comes with a temperature probe for Nixx charging, it has a full set of JST-XH balance connectors on the side and it comes with a set of output leads. All that you will need to do is put the correct connector on to match your battery leads.

What's in the box. (Note: I have modified the main
output leads. They come with small alligator clips
from the factory.

There are a few accessories for the iChargers. They include the P350 power supply and several awesome balance boards for all types of balance connectors.

The ultimate charger setup! The parallel charging
wiring adapters are available at ProgressiveRC.

The 3 most popular balance boards.
(JST-XH, TP and Hyperion)

Using the iCharger 206B
Instead of covering all aspects of the 206B, I will be outlining a few of the things I do on a regular basis with my iCharger and then I will be expanding on the 206B's requirements, capabilities and other cool features.

Please read through the very informative manual for a full explanation of the capabilities of the 206B.

Charging a lipo
Start by getting the charger out and plugged into the power supply. Then turn it on and let it boot up. The screen shown after boot-up is the last thing that was done on the iCharger, which is almost always charge a lipo. Next connect the pack. The charger will auto-detect the cell count in "LiPo Balance CHG" mode, so all that may need adjusted is the charge rate. If the charge is acceptable, then just press and hold "Start" for a second to begin charging. If the charge rate needs adjusted, press "Start" twice to to highlight the charge rate and then use "Dec" and "Inc" to adjust it. Once the charge rate is adjusted to the appropriate value, press and hold "Start" to begin charging.

Once charging has begun, the screen displays very useful information including the charge mode/# of cells, charge current, battery voltage, mAh replaced and time elapsed. Pressing "Inc" displays the cell voltages. Pressing "Dec" cycles through several settings and info screens including end charge voltage, capacity cutoff, safety time-out, temp cut-off, measured temps, and measured input voltage.

One very cool feature of the iChargers is that most of the settings related to the current charge cycle can be altered while charging. Pressing and holding "Start" at the main charge screen allows for the charge rate to be adjusted while charging. Simply adjust the charge rate and then press "Start" again to accept it. The charger will immediately adjust to the new setting. Likewise when while viewing one of the settings, pressing and holding "Start" will allow you to modify that setting. Again pressing "Start" again will accept the adjustment.

When a charge cycle is started the current ramps up very quickly. The fan will run as needed, but much of the time it can remain still. Once the lipo has reached 4.2V per cell and the current has dropped to the specified value (adjustable in the settings), the charger signals the end of the charge cycle with a "Done" in place of "LiPo" in the left corner and by sounding an alarm (alarm type is adjustable in settings).

Using "test mode"
One of the most handiest features of an iCharger is what is referred to as "active test information" in the manual. Simply put it is a set of information screens that let you view the input voltage, pack voltage, temperatures, cell voltages and internal resistance of both the pack and individual cells. I use this "test mode", as I call it, to check my power supply voltage, see if packs are charged, check their balance and measure the pack's internal resistance.

To use "test mode", start by getting the charger out, plugging it into the power supply and powering it on. The charger will boot up and eventually display the last screen used, the LiPo Balance Charge screen in my case. From here press and hold "Stop" for 3 seconds to enter the test mode. The initial screen shows the input/output voltages and int/ext temps. Pressing "Dec" will measure and display the internal resistance of the pack. Pressing "Inc" will show you the individual cell voltages.

As a note you do not have to have a pack connected to enter the test mode. In fact once in test mode you can connect and disconnect as many packs you would like to check them. This is very handy as it allows you to run through all your packs in a short amount of time in order to note both their charge state and their health.

Input requirements of the 206B
Like many of today's powerful chargers, the input power requirements for the 206B can be a bit confusing. So let me try to explain the requirements clearly. The charger will function on a variety of inputs voltages from 10-28V but for maximum output an 18V input must be used. See the chart below for an idea of the output wattage given different voltages.

Estimated output on different input voltages
Input voltage
estimated output
12.0V 227W
13.8V 261W
15.0V 284W
17.0V+ 300W

The iCharger P350, 15V 350 power supply, is a suitable choice for most 206B owners but understand that it may limit output slightly. For those planning to use the full output of the 206B on a regular basis, I would recommend a 24V power supply with a minimum output of 350W.

Output capabilities of the 206B
The 206B is rated for charging 1s-6s lipos at up to 20A or 300W, whichever comes first. Below is a chart showing the real world charge rates that can be achieved with the 206B.
Maximum lipo charge rates for the 206B 
(assuming a proper power supply is used)
# of Cells
Initial charge rate (3.7V per cell)
Final charge rate (4.2V per cell)
1s 20.0A 20.0A
2s 20.0A 20.0A
3s 20.0A 20.0A
4s 20.0A 17.9A
5s 16.2A 14.3A
6s 13.5A

I regularly parallel charge 2x 6s 2600mAh packs at 13A, so I can confirm that the 206B is indeed capable of outputting its full 300W, and with relative ease.

Adding an external load for greater discharge rates
The 206B will allow for an external load to be added in order to increase the discharge capabilities of the charger. In this mode the charger acts as the controller while the external load does the discharging. This allows the charger to monitor the pack while discharging, as well as terminate the discharge when the appropriate voltage is reached.

Soon regenerative discharging will be an option. This utilizes a deep cycle battery as a load and charging it in order to discharge. This is a great way to cycle batteries as it allows for fast discharges but does not waste all the energy.

Wide variety of adjustable settings
Unlike most chargers, almost everything in the 206B is adjustable. Let me give you a few examples and how they can be useful.

The lipo termination voltage can be set manually. It defaults to 4.20V but lowering it can speed up charges and help the batteries last longer.

The lipo balance charge termination charge current can be adjusted. The default is I/10. This means that the charger will stop charging when the current drops to the set charge rate divided by 10. So for example if you were charging a 2200mAh pack at 2.2A, it would stop charging when the charge rate reached .22A. The other options are I/5 (this will raise the value to speed up charging) and I/40 (this will greatly lower the value to increase the accuracy of the charge).

The capacity cut-off can be set to anywhere from 100-99900mAh. Being able to adjust this is very handy when parallel charging.

In conclusion
The iCharger 206B is a popular choice these days and it is not hard to see why. It offers a large feature set, a respectable amount of output and all at a very reasonable cost.
Specs - Features - Photos


Input voltage range 10 - 28.0VDC
Charge current range 0.05 - 20.0A
Discharge current range 0.05 - 20.0A
Maximum charge power capacity 300W @ input voltage > 18V
Maximum internal discharge power capacity

Maximum external discharge power capacity 500W @ 25V/20A
Current drain for balancing <350mA
Balance accuracy <10mV
Lithium (LiPo/LiIo/LiFe) battery cell count 1 - 6 series (In non-balance mode, expand LiFe to 8s)
NiCd/NiMH battery cell count
1 - 17 series
Pb battery cell count 1 - 12 series (2 - 24V)
Log Files storage 16Mbit (36 hours)
Battery setup memories 10
Intelligent temperature control Yes
PC Connect USB Port
Weight 350g
Dimensions (L * W * D) 134 * 83 * 25mm   
(5.28" * 3.27" * 0.98”)

  • High power, high current, high-performance power conversion circuit. The iCharger series uses advanced Synchronous buck-boost DC/DC converter technology with an output conversion efficiency that can reach over 90%. This not only saves power and reduces heat build up but also makes the charger more compact and conveniently mobile.
  • Input power with 4mm bullet connectors (25A) butt-welded alligator clips and wide input voltage ranges from 10V to 28V. The output power can be adjusted to align with the available input power, thus preventing input current overload and protecting the DC source.
  • The iCharger series can be used with three types of Lithium batteries - LiPo, Lilo, LiFe - and has a fully integrated cell balancer.
  • Internal temperature sensor and temperature controlled automatic cooling FAN controls the internal temperature and provides intelligent protection. When the internal temperature is over 60℃(140 oF), the output power is automatically reduced by 25%. If the temperature exceeds 65℃(149 oF) the charge cycle is stopped.
  • Convenient set of 10 battery profile memories that can be saved and loaded by number.
  • 2x16 backlit LCD screen that provides rich information including active mode, current, voltage, total charge (mAh), charging time and temperature etc.
  • Various charging/discharging settings and cycles to meet a wide range of customer needs. For Lithium batteries: balance charging, normal charging, fast charging, storage, discharging, ext-discharging, charge/discharge cycling, and battery monitoring. For NiCd/NiMH batteries: charging-auto, charging-manual, discharging, charge/discharge cycling and forming charge. For Pb batteries: charging and discharging.
  • Unique Lithium battery expanding discharge program. When you connect the external capacity resistance, you can use it as the maximum discharge power capacity—500W (@25V/20A).
  • Unique Lithium battery Monitor program. When you use other equipment to charge or discharge a Lithium pack, you can use the iCharger to monitor the per-cell voltages, battery temperature and process time. If any individual cell appears over-charged or over-discharged or the pack is too hot or the process has gone on for too long, the iCharger will generate an alarm sound and the related information will blink.
  • Electric motor test mode can be used to run-in electric motors, test motor parameters and performance, check tolerances etc.
  • Foam-cut drive. In this mode, the charger acts as a convenient power supply for a hot wire foam cutter.
  • Battery internal resistance measurement. The iCharger can not only measure the internal resistance of the battery pack, and also can measure the per-cell internal resistance (only available for lithium battery).
  • Perfect protection. The iCharger has protection for reversed polarity (input or output), low input voltage, battery temperature, charging capacity and time overrun.
  • iCharger 206B has a 16Mbit flash storage, which can log offline charge and discharge data in 36 hours.
  • Support upgrading the hardware program by USB port. The iCharger also support the “LogView” software and can display, plot and analyze the charge and discharge data by it. (See detail information about LogView in the following website: http://www.logview.info)
Future additional feature: Regenerative discharging is coming for all iChargers. There is currently a beta firmware that supports the feature but it has not been fully tested. The final release should be coming soon.

The iCharger 206B comes in a well padded box and includes a CD, USB cable, temp sensor, charge leads (with small alligator clips), large alligator clips for input leads.

Here is a link to the user's manual for more info. The iCharger manual is one of the more detailed manuals I have come across.

Stock photo

Additional photos

The setup for measuring the 206B's output capability.

The setup for measuring the 206B's input needs.

I always splice in some bullets on the input leads to
make things more versatile and simple to pack up. This
does not void the warranty on any charger I know of. 

iCharger 206B vs its big brother, the 208B.

206B vs 208B

206B vs 208B

Testing the 206B
Below are several tests of the 206B. They include max output at various input voltages, input needs for several outputs, the estimation of the 206B's DC-DC efficiency, etc. A G.T. Power Watt Meter was used to measure the input and output current, voltage and wattage in each test.

First to test the maximum output capabilities of the 206B at different voltages. A power supply with an adjustable output of 12-17V was used for the input. All measurements were done with the watt meter. A 6s pack was used as it offered the most load on the charger.

Measured output on different input voltages
15V 304W
17V 312W
24V 312W

Input current and wattage for various situations
6s charge rate selected
5A 12V
5A 17V
10.3A (12V max)
13.3A (17V max) 17V

Charger efficiency in various situations
119W 11W
241W 26W
268W 242W

333W 312W
328W 312W
16W 95.1%

So what does all this mean? Well I see that it backs up all the specs of the iCharger 206B and shows that most are actually slightly conservative. For example the manual estimates the output wattage on 12V to be 227W but I measured 242W. Even more surprising the manual estimates the output wattage to be 284W on 15V but I measured 304W, or more than the charger's overall rating on paper. This means that a user can indeed get a full 300W off a 15V input voltage like that of the iCharger P350 power supply. In fact that power supply seems almost perfectly sized for the 206B, like it was made just for this purpose ;)

The iCharger line shows the best efficiency of any charger I have met or read about. Most fall into the low 80% range when charging a 6s pack off 12V. Good job!

Note: There is some error involved with all these measurements. The meter is not 100% accurate but should be close enough for these needs. The pack being charged was at slightly different voltages for each test due to state of charge and charge load. An average voltage of 23V was used in the calculations.

Additional info and updates
  • May 7th, 2011 - I had a mishap concerning the balance ports and a loose banana plug. It was my fault and in order to fix it, I opened up the charger. Normally I open up everything to see how it is made but for some reason I just used the 206B and never opened it, until now. What did I find? An extremely well laid out and simple design. I was very impressed. Here is a pic
  • Dec. 9th, 2010 - Finally got the charger tested on 24V. I used my DIY 24V 47A PS for the tests and have added the new numbers above.