iCharger 208B Charger Review

INTRODUCTION



Battery Chemistry Charged: 1-8 cells LiXX, 1-25 cells NiXX, and 1-18 cells lead-acid
Input Voltage: 4.5 to 32VDC, reverse polarity protected
Outputs: Banana jacks and a 9 pin balance port
Output Current: Up to 20A, reverse polarity protected
Output Power: Up to 350 Watts
Internal Discharge Power: Up to 30 Watts
Max Discharge Power: Up to 600 Watts
Balancing Current: Up to 350mA
Balancing Accuracy: Within 10mV
Charge Rate: 5mA to 20A
Data Memory: 16Mbit (36 hours worth)
Size: 143mm x 97mm x 26mm (5.63"x3.82"x1.02")
Weight: 420 grams (15.8 oz)
Warranty: One Year
Available From: ProgressiveRC
Price: $169.99

The iCharger brand of chargers by Junsi (aka HillRC) is a relatively new kid on the block that has been getting a lot of attention for their high powered chargers combined with a small physical size and aggressive pricing. Another reason they caught my eye was their thread on RCGroups where they listen to customer feedback and use the feedback to fix bugs and add features. Prior to this the only other charger manufacturer that I knew of that openly listened to customer feedback was FMA.

As you can see by the picture immediately below, the iCharger 208B is only slightly larger than the FMA Multi4 yet boasts seven times the power and twice the output cell count.


My beloved Cellpro Multi4 charger beside the promising new iCharger 208B.

The PC interface is simply a USB cable which at first glance appears to be a great idea as we all have tons of them around and won't need to store yet another specialized cable, but it turns out that this is a somewhat special USB cable so you still need to keep track of it and only use it on the iCharger.

The iCharger 208B is designed and manufactured in China which in and of its self does not dictate a low quality product, but as will be shown later there is plenty of room for improvement. Should your 208B need serviced or replaced your first point of contact is the retailer that you purchased the unit from. This is one of the reasons why I purchased my 208B from David at ProgressiveRC and recommend others within the USA do likewise. The excellent service and fast shipping from ProgressiveRC is well worth the extra $20 or so you'd save by buying this charger from a big RC retailer in China (including costs for shipping).

My iCharger 208B was one of the earliest released so it has firmware version 3.09 where as current models are shipping with version 3.13. With version 3.13 iCharger has entered a lengthy limbo where the "stable" release stopped at 3.13b some time ago and the "beta" release is now at 3.13f with chargers shipping with versions somewhere in between. The only major addition since 3.09 that I am aware of is regenerative discharging. For this review I will be using version 3.09 as it has worked well enough for me and I am not inclined to mess with something that isn't broken.

FEATURES


  • Multi-chemistry (LiPo, LiFe, LiMn, LiIon, NiCd, NiMH, and lead acid)
  • 1-8 LiXX cells balanced, 1-10 LiFe cells unbalanced, 1-25 cells NiCd/NiMH, and 1-18 cells lead acid
  • 4.5 - 32.0 VDC supply voltage range
  • 350 Watts output power with 18 VDC supply (about 270W with a 12 VDC supply)
  • 30W internal discharge and up to 600W in "expanded" or "regenerative" discharge mode
  • 5 milli-amp to 20 amp charge current
  • 5 milli-amp to 20 amp discharge current
  • Balances cells to within 10 mV (balanced mode only)
  • 350mA balance current
  • Storage charge mode
  • 16Mbit internal memory can store up to 36 hours of data
  • Automatic cooling fan
  • Cell internal resistance measuring mode
  • Special modes such as foam cutting and motor test
  • Temperature probe with configurable high temperature safety shut-down
  • Backlit LCD
  • User configurable charge settings
  • PC interface (includes firmware update capability)
  • Metal enclosure

Safety

The integrated balancer in the 208B gives it an inherent safety not obtainable by unbalanced chargers, even if coupled with an external balancer. However, the 208B does not require the use of the balance tap and can charge the full 20A in unbalanced mode which is no better than the chargers of old. The 208B has access to several safety features but does not always enforce them, so you've got plenty of rope to hang yourself with it if you so choose. For a novice this could be a dangerous combination, but an experienced power user may very well enjoy freedom from being dictated what constitutes "safe" by the manufacturer.

Chemistry support

All manner of lithium batteries are supported, including LiPo, LiFe (A123), and LiMn. Additionally, the 208B can charge NiCd, NiMH, and lead-acid batteries. Lithium packs of 1-8 cells can be charged in balanced or unbalanced mode. Similarly, LiFe (A123) packs of 1-8 cells can be charged in balance mode or 1-10 cells in unbalanced mode. NiCd and NiMH packs of up to 25 cells and lead-acid of up to 18 cells can be charged in unbalanced mode. Basically any cell combination of most any rechargeable chemistry with a termination voltage of 36 volts or less can be charged.

Connectors

Power is supplied to the 208B via 14 AWG wire with banana plugs and removable battery clamps that are ideal for clipping onto a deep cycle lead-acid battery. The battery pack to be charged is connected via 16 AWG output cables with banana plugs on one end and little alligator clips on the other. There is also a 9-pin plug to be used with the optional balance board. Between the output banana jacks and the balance port connector is a 3 pin connector for the temperature probe. The USB connector is on the other end of the charger near the input cables.

If the 208B is being powered from an AC powered power supply then a potential path for ground current between a PC and the 208B exists via the USB cable. The correct solution to break this loop is the use of opto-isolators, but the 208B breaks the loop by disconnecting the ground wire of the USB cable. It is an inferior but less expensive solution to the problem. I have seen a laptop get fried by current through the ground wire of a USB cable so this is not an unnecessary precaution. Do not use a standard USB cable with the 208B.

Power and current capabilities

The power supply to the charger must be capable of supplying 25 amps at >17 volts to get the full 350W output, but a a lower voltage power supply will work fine and will just produce less output power. The 208B can also be set to limit the input current when using batteries or power supplies that cannot supply 25 amps. Basically you can use any power supply you want as long as its output voltage is 4.5 - 32.0 VDC and you set the current limit if needed.

Other features

The 208B has built in 16Mbit flash memory that can be used to record charging data while away from a PC at the field then downloaded later when at home. If you're the kind of person that likes to save all of the plots of each charge then this is an essential feature. Even if you only save every 10th or 20th plot this gives you the ability to record that data while in the field. Another feature not seen in all chargers is a temperature probe that can be used to record pack temperature and even activate a safety shutdown if the pack gets to hot.

BOX CONTENTS


As shown in the picture to the right, the following come in the box:
  • iCharger 208B charger
  • Banana to alligator clip adapters
  • Output cable with mini aligator clips
  • Temperature probe
  • Special USB cable
  • CD with software and manual in PDF format
  • Four rubber feet

The 208B and included accessories

OPTIONAL ACCESSORIES


This really shouldn't be considered optional, the reason that adapter boards are a separate item is that we all use a different one and some people may need two or more types. A variety of them are available from ProgressiveRC for $9.99 each. I have three of the TP kind and am a big fan of them as they have the bulit in ability to connect balance taps in parallel and serial.


Optional balance tap adapter board and Deans style output cable

Also shown in the picture above is a 16 AWG output cable with banana plugs and a Deans style plug. A similar cable with a JST style plug is also available and if you order from ProgressiveRC you can choose from a large range of output cables, parallel cables, and adapter cables. This isn't an advertisement for ProgressiveRC, but since my experience with the 208B includes my purchase and accessories available from that retailer I would be remiss not to at least mention where I got everything shown.

MANUAL


The manual is 33 pages long and reflects its Chinese roots with very poor wording. I am told some native English speakers have helped clean it up a bit and it does show as it is a lot better than some manuals I have read (eg. Turnigy-5011 ), but be prepared for some very unusual choices of words.

The 208B menus and manual layout echo many of the popular chargers so there is a good chance you may already be familiar with the layout and will quickly catch on. For me this was my first charger with this kind of menu so I had to refer to the manual a lot and I felt like the information was very disconnected and I would often have to reference 2 or 3 sections of the manual just to figure out how to change a specific setting. Over all I rate the manual a "B" as all the information seems to be there and is fairly understandable, but it still has room for improvement.

PICTURES



Top view

DC power input cables and USB connector

Output banana jacks, temperature probe jacks, and balance port

Charging a 3S LiPo battery using a TP to CellPro adapter board

The front of the 208B circuit board

The back of the 208B circuit board

CHARGER MENU


The 208B menu may be familiar to some due to its similarities with some other chargers, but it may be new to some folks so I'll try to explain how to look at this map. When you turn on the charger you are usually in a selection in one of the right four columns of the map shown below. Pressing "Stop" will cause you to move up a level to the "PROGRAM SELECT" menu which is shown by the left column of the map. Pressing "Inc" or "Dec" button will then cause you to move up and down it (note the blue text indicating this). Pressing the "Enter" button causes you to move right again. The other four columns are all part of the secondary menu level so you press "Inc" and "Dec" to move between. Once you've had a few moments to practice navigating it is really pretty simple to understand and get around. Once you get to the setting you want, such as "LiPo Termination Voltage" press "Enter" to modify the setting, press the "Inc/Dec" buttons to change it, then press "Enter" again to accept your change. Note that the regenerative discharge feature is shown in this newer version of the manual even though it isn't available in my older firmware.

Each of those boxes in the right four columns is repeated in the following pages in the manual with directions on what can be changed and what effect it will have. You'll want to become familiar with the differences between the various LiPo charge modes as there are no less than 8 variations. Some require the balance tap to be connected while in others it is optional. If the balance tap is required to be connected then the balancer is active while in the other modes the balancer is not active and connecting the balance tap simply allows you to monitor cell voltages. Not to worry, there is a nice table that describes it all in detail.


The menu map shown in the manual

BATTERY CHARGING EXAMPLES


Charging Safety

The safety rules for charging your batteries are probably no further away than the labels on your battery packs, some of these rules are as follows:
  • Do not charge a battery unattended
  • Do not charge near flammable objects
  • Do not exceed the rated cell voltage for your ambient temperature (typically 4.25 volts when above 32F)
  • Do not charge a damaged battery pack
  • Stop the charge if anything unusual occurs, including but not limited to excessive heat and puffing of the cells

Connection order

With small packs of 2 or 3 cells the voltages are so small that no sparks are seen or heard so not much attention is paid to connection order. But once you start to connect an 8S LiPo to your charger you may be startled by the loud pop and spark that result. To help combat this spark and potential damage to connectors the 208B has a recommended order of making connections; it is:
  1. Connect the power source to the 208B and turn it on (if applicable)
  2. Connect the balance tap (if applicable)
  3. Connect the positive connector of the battery to the charger then the negative lead (you can do this with the banana plugs)
  4. Perform charge or discharge operation
  5. Disconnect balance tap and main lead from the battery then power down the charger

Quick Start

The 208B manual does not provide a "quick start" guide in the manual which often leaves new users asking the most basic question of how one goes about initiating a charge. Therefore I offer two quick start examples in order to demonstrate a typical usage. For these examples assume that the charger settings are adequate and do not need adjusted. Even if your power supply would normally require you to limit the 208B input current or set an input watt limit we can safely ignore that for now simply by choosing a very low charge current that won't stress the power source.

The first example assumes that the last battery charged was not a LiPo and none of the charge parameters are correct and they will all need changed. The second example assumes the last battery charged is identical and all of the parameters are correct so nothing needs changed.

Balance charging a LiPo pack (assuming all last pack was not a LiPo and all settings need adjusted)
  1. Power up the charger
  2. Plug in the battery to be charged (in the proper order listed above)
  3. Press "Stop" once to enter the "PROGRAM SELECT" menu if not already there
  4. Press "Inc" till "Lithium Battery" is shown
  5. Press "Start"
  6. Press "Inc" as needed to reach "LiXX BALANCE CHG"
  7. Press "Start" then if needed press "Inc" to select "LiPo"
  8. Press "Start" then if needed press "Inc" or "Dec" to set a suitable charge current
  9. Press "Start" then if needed press "Inc" or "Dec" to select the pack's cell count
  10. Press and hold "Start" for more than 3 seconds till the charger screen changes to "BATTERY CHECK"
  11. When prompted, press the "Start" button to verify the cell count
  12. While charging press "Inc", "Dec", and "Start" to view the various information available
  13. To terminate the charge press "Stop"
Balance charging a LiFe pack (assuming last pack was identical to this one)
  1. Power up the charger
  2. Plug in the battery to be charged (in the proper order listed above)
  3. Visually verify the screen says "LiFe BALANCE CHG" and that the charge current and cell count are correct
  4. Press and hold "Start" for more than 3 seconds till the charger screen changes to "BATTERY CHECK"
  5. When prompted, press the "Start" button to verify the cell count
  6. While charging press "Inc", "Dec", and "Start" to view the various information available
  7. To terminate the charge press "Stop"


Data displayed on the LCD while charging

Depending on the preset being used the following may be displayed on the LCD screen while charging:
  • Chemistry and cell count
  • Pack volts
  • Charge current
  • mAh charged into the battery (or discharged)
  • Elapsed time
  • Cell voltages
  • Termination voltage
  • Capacity safety cut-off point
  • Safety timer cut-off point
  • Temperature cut-off point
  • Internal and external temperature
  • Supply voltage

Pressing "Start" will always cause the initial screen to display which contains the first five items that are listed above. Pressing "Inc" will cycle through the cell voltages while pressing "Dec" will cycle through all the other items listed.



Canceling a charge

If at any time you wish to cancel the charge simply press the "Stop" button. Some don't like how easy it is to bump this button and accidentally terminate the charge, but from a safety standpoint it is refreshingly quick and easy. One complaint I have is that if you have button beeps turned off you won't get a beep acknowledging the cancel so you have to go off of the data displayed on the screen to verify that the charger halted the charge.

Error messages

If there is a problem during the charge an error message will be displayed. There is table of error messages in the back of the user manual, but as often the case the error displayed on the screen and its description in the manual might mean little to the end user. In the case that the message doesn't help you find the cause of the problem it is useful for asking others what could cause that message to pop up or in determining if repairs need to be made.

SOFTWARE


The 208B uses two software programs, one for plotting data and another for updating the firmware in the charger. If you don't care to plot your data then you may very well not use any software unless you decided to update the firmware to get a new feature or bug fix (such as the new regenerative discharge feature). The firmware updating utility is created and maintained by Junsi, but for plotting the data they use a third party application called LogView that is free to use.

Graphing

The Logview software enables plotting various information depending on the charge type. This is typically individual cell voltages, pack voltage, charge current, power, charge (aka capacity), and temperature. Pages 30-31 of the manual (pages 29-30 of the old version) describe the basics in how to connect the 208B to LogView so I won't repeat them here.

Before I show pictures of 208B charging plots displayed in LogView I should mention that while LogView has a English language setting, much of the German that the software writers use leaks through all over the place. I'd hate to support two languages in my software so I don't begrudge the software authors, but make sure you know how to find the meaning of words like "Ja", "Nein", and "Abbrechen" as you won't get very far into using LogView before encountering them.

Below and on the left is the default view you'll see when you load new data into LogView. Not only does it look extremely cluttered, it is nearly impossible to use like this so you'll want to uncheck the boxes at the left to remove plots that you are not currently interested in viewing. The picture below and to the right shows what this looks like if you just wanted to view the six cell voltages in this pack. Notice that cell 4 was lost in the noise but now we can instantly see that it is bad and needs replaced. The voltage range for cells 1-6 are all shown and they can be scaled individually or as a group. This can be very useful if you are trying to "zoom" in on an area of the graph. Having identical scales shown to the left and the right for each of the six cells is a bit annoying as you would probably never want to view them on different scales. If there is a way to combine then to a single scale I don't know how and don't believe there is a way to do so. This is the drawback of having a generic plotting utility that does not know how the data is associated with each other.


Plots of a 12A balanced charge of a 6S2P 2300 mAh LiFe pack.

You can plot data from the 208B as it operates (if plugged in via the USB cable) or you can download saved data from the 208B flash memory. Once you've got the data loaded into LogView you can save it to a file on your PC.

Firmware updates

The manual includes a set of directions on updating the firmware on page 29 (or page 28 in older versions of the manual). It is a simple process:
  • Install the iCharger 208B USB driver (directions for this located on the same page)
  • Run the upgrader program that came on the CD or website location given in the manual
  • Connect the USB cable provided with the charger
  • Select the 208B in the device list
  • Click the "Open" and select the new firmware file (optionally follow the directions on how to download the firmware)
  • Click "Update..."

USER FEEDBACK


Junsi maintains a thread on RCGroups for the iCharger line of chargers and uses it to communicate with their customers. In the 2.5 years that the thread has been active customers have used it to report bugs and request new features or modifications to how the charger behaves and the messages that are displayed on the screen. These suggestions and bug reports have been accepted with amazing open mindedness by the manufacturer, including adding the foam cutting feature as suggested by one of the forum members. This has not been without its drawbacks though as opinions vary on how the charger should behave so sometimes you get someone requesting a modification and someone else asking for it to not be changed. Overall it works fairly well though and Junsi always has the final say on everything, as you would expect.

ACCURACY


I am a stickler for details and accuracy, when I see a product like the 208B I want to know just how accurate it is. The charger may say it just charged my cells to 3.19 volts at a rate of 3.1 amps, but I want to know what the voltage and current really is. The 208B manual states that it balances cells to within 10mV, but offers no other indication of how accurate it should be. My reference for checking voltage and current accuracy is a Fluke 87-V which has a DC voltage base accuracy of 0.05% and a DC current base accuracy of 0.2%. All measurements were performed using a charge scenario chosen to minimize that rate of change of the parameter being measured. I have also included a few measurements from my Watt's Up meter as a point of comparison. The numbers in the parentheses are the percent error as compared to the Fluke 87-V DMM.

Fluke 87-V DMM 208B Watt's Up meter
Cell Voltage (V): 3.167 3.17 (0.1%) -
Pack Voltage (V): 9.410 9.36 (0.5%) 9.36 (0.5%)
Pack Current (A): 3.108 3.1 (0.26%) 3.08 (0.9%)
Charge (mAh): 4043 4083 (1.0%) 3972 (1.8%)
Watts (W): 30.7 29.2 (4.9%) 30.6 (0.3%)
Temperature (C): 27.3 26 (4.8%) -

Let's take a look at how the 208B measures up. In the first row we can see that the cell voltage is displayed very accurately and the pack voltage in the second row is also quite accurate. The charge current is very accurate, even beating out the Watt's Up meter. Measuring power and charge with the Fluke 87-V is not a direct process and requires the product of two measurements, voltage and current for power, and current and time for charge. Since these additional measurements are error prone I use them as a basis for comparison only. The measurements for charge are fairly close across the board, but the 208B measure of power and temperature have nearly 5% error. With the exception of the low indication of power and temperature these results are very good.

The 208B is advertised to balance cells to within 10mV. To test this claim I charged a 3S LiPo pack in balance mode and measured the voltage shortly after the termination of the charge. A typical result is shown in the table below. As before, the number in the parentheses is the percent error. Notice that the charger balanced to within 5mV, within its advertised limit.

Fluke 87-V DMM 208B
Cell 1 (V): 4.193 4.19 (0.07%)
Cell 2 (V): 4.185 4.19 (0.12%)
Cell 3 (V): 4.191 4.19 (0.02%)

HARDWARE ISSUES


One of my concerns with purchasing and using the 208B was the quality of the hardware. Thanks to postings on RCGroups I knew the predecessors to the 208B had a clearance problem where a coil in the charger's power supply would rub against the metal case and could short out.

Right away I noticed that the cooling fan was very noisy and had a mechanical sound to it. After several hours of use the sound was slightly better but still very bad so I took the charger apart to investigate. What I found was that the fan was of such poor design quality that the stator was not held securely in place which allowed the spinning fan blades to move into contact with the housing. A little epoxy between the stator and housing and on the power wires held everything in place allowing the fan to run much more quietly and at a tolerable sound level.


Fan stator and wires held fast with some epoxy.

Since the case was now open the next item to check was that inductor coil clearance problem present in the iCharger 106B+ and 1010B+ had indeed been fixed. The manufacturer had promised a fix so I was shocked to discover that instead of fixing the problem they added some tape to the case where it presses against the coil. If you closely examine the pictures below you'll see that the tape was completely ineffective and looks to be worn through or soon will be and it is already starting to work on a hole in the wrap around the coil. My solution was to remove the tape and grind away some of the case material with a Dremel tool till there was plenty of clearance.


The patch job with the tape didn't help one bit and it is only a matter of time before a short is created.

Miffed at finding the design flaw still existed despite a promised fix I posted my findings on RCGroups and Junsi soon after responded with a picture of a new LCD screen that would allow repositioning the coil slightly away from the case. Now that really ticked me off, the promised fix was available when I received my new charger but yet I still get sold a flawed design and they knew it (Ford Pinto anyone?). I have no idea if they still make the 208B with this design flaw or not so buyer be warned.

Now that I was alerted to the use of tape in an attempt to rectify design flaws I looked around and quickly discovered another application. Here the tape is being used to keep the metal body of the capacitor from shorting the leads of the FET. Everywhere I've ever been employed this wouldn't be permitted and the product would be revised.


Tape used to keep the capacitor body from shorting out the FET pins.

I found these hardware issues disconcerting but was able to rectify them fairly easily once the case was opened. I didn't see any other signs of design flaws or shoddy soldering so I am confident that my modified 208B will last many years. My genuine hope is that the iChargers will continues to improve over time and with each new model as there is clearly room left for improvement.

CONCLUSION


Junsi has continued to improve on their earlier iCharger designs and has created the 208B which represents a lot of charging power in very small package at a fair price. It is very feature rich with the ability to charge or discharge nearly any battery that you own and several useful modes such as IR measurement and foam cutting. While the design quality leaves much to be desired, it doesn't appear to be a major problem and other users have reported satisfaction with the warranty service. I have no problem recommending the 208B to people looking for 8S charging and 350W at the $170 price point as long as they are aware of the potential hardware issues discussed in this review and how your choice of retailer determines how easy it is to get warranty support.

Pluses

  • PC interface cable is included with the charger (but don't use it on anything else)
  • Backlit LCD is easy to read in a wide range of light conditions and viewing angles
  • Good use of significant figures doesn't give a false sense of accuracy
  • Not requiring the use of safety features can be enabling for experienced users
  • Multiple battery chemistry support
  • Access to the manufacturer and a large and knowledgeable user base at RCGroups
  • A good value of watts per dollar (about 2 Watts per $1 USD)
  • Built in 16Mbit data memory
  • A wide range of very useful adapter boards and cables are available for the 208B

Minuses

  • User manual is difficult to read and understand (but not as bad as some)
  • Not requiring the use of safety features can be hazardous for novice users
  • Hardware issues that required opening the case to resolve
  • Plotting software is very generic and has a severe language barrier.
  • IR measurement is a separate function so it cannot be saved along with other plotted data

DISCLAIMER


I am in no way affiliated with iCharger or Junsi. I purchased my 208B from ProgresiveRC at full retail and do not stand to benefit monetarily from positive comments, nor do I risk losing monetary benefits by posting negative comments. I reserve the right to update this review as needed to correct mistakes and update information that may come to light later or is changed by firmware upgrades. Rather than allow this review to quickly become outdated by firmware updates I will endeavor to keep it up to date and accurate.

COMMENTS?


If you have any questions or comments regarding this review please feel free to do so on my RCGroups blog.