Great Planes ElectriFly Brand Triton Jr. Charger, Discharger, Cycler - RC Groups

Great Planes ElectriFly Brand Triton Jr. Charger, Discharger, Cycler

Jeremy Zorns provides a detailed look at the beloved Triton's new little brother, the Triton Junior.

The Triton Jr.'s bright blue LCD display & membrane keypad.


In my average-size hand, for a size reference.
In my average-size hand, for a size reference.
Length:4 5/8 (118 mm)
Width:3 5/8" (92 mm)
Thickness:1 3/32" (30 mm)
Weight:12.7 oz. (362 g)
Display Size:2 1/2" x 9/16" (62.7 mm x 14.3 mm)
Input Voltage: :10-15V DC

Battery Types, # of cells
LiPo or Li-Ion:1-4
(3.6 or 3.7V cells)
Pb:2, 4, 6, 8, 10, 12V

Fast Charge Current:
(0.1A step, 63W max.)
LiPo/Li-Ion:1C rating (63W max)

Peak delay at start:3 minutes fixed
Discharge Current:0.1-1.0A
(0.01 step, 5W max.)
Cycle count:1 to 5
Battery Memory:one
Available Online From:Tower Hobbies

When it comes to DC chargers and cyclers, for the longest time, the Triton has been the standard, but its typical $125-130 price point was a bit high for many modelers' budgets. There is a demand for a compact but full-featured all-in-one charger similar to the popular Triton, but at a lower price point.

This year, Electrifly has added another member to the family tree, the Triton Jr. It is smaller than the Triton, but retains the most-valued features.

Lets take a look at this full-featured charger, which will easily fit in your field box, or would make a good backup charger so that you can charge more than one battery at a time.

What's Included?

  • Charger with input leads
  • Instruction manual
  • Quick start sheets for each supported battery type

How to Operate the Triton Jr.

Jeremy's Quick Start

  1. Clip the input leads onto a 12 V source
  2. Momentarily press the 'BATT TYPE' button until your battery type is shown on the screen
  3. Momentarily press the up or down arrow until the feature you want shows up. (charge, discharge, cycle, etc.)
  4. Momentarily press 'ENTER/START' to get the value blinking, then use the up & down arrows to set the value.
  5. Press and hold 'ENTER/START' until the charging/discharging starts
  6. That's it!

After I had read the manual and charged a few batteries (of different types) with the Triton Jr., I found that I didn't need to keep the manual on hand any more. This is perhaps one of the strongest things I can say in favor of the logical operation of a computer charger.

I thought the blue backlight was a little too bright. It is actually so bright that it washes out the LCD segments to some degree. I would have liked to see either a way to reduce the intensity of the backlight or to increase the contrast of the LCD segments themselves. As it is, I had to look at the display a smidge longer than I would have liked to to see what was going on. It's not hard to read, by any means, but it could be easier. (I have 20/20 vision, for the record.)

There is a safety timer built into this charger. For nickel-based batteries, fast-charge time is limited to 1.5 hours. For Lithium types, it's limited to 2 hours. I don't mind the timer for lithium type batteries, as there is no advantage to slow-charging them. I was irritated that I could not set a low charge current and charge my NiMH packs at very low rates without having to continually restart the charger or let it go to trickle charge from a higher setting. (Slow charging is how the cells in nickel-based backs balance.)

The bright side of this programming is that if you plug in your LiPo battery pack, but forget to switch the charger to LiPo mode, it can only charge 1.5 hours. This will probably be enough to puff up the battery pack and ruin it, but probably won't be enough to make it burst into flames and burn down your car/house/garage/shop.

Instruction Manual -- First Rate!

Before I used the charger for the first time, I read the instruction manual, cover to cover. I have two other chargers from two other makers, and neither of them has a manual to rival this one. Great Planes/Electrifly has a well-earned reputation for writing clear manuals. I could also tell right away that it was not translated from any other language, but written in English as its first language. This is refreshing in this day and age.

What's so great about it? A fair question. Knowing full well that many of the users will not want to read the whole manual before using the charger, Electrifly put a Quick Reference Guide as the first item after the introduction. Additionally, two double-sided "menu maps" are provided that cover quickly and visually show the user how to navigate the menu for each battery type.

What I recommend is learning enough about the charger to get your first pack charging, discharging or cycling. While that is going, grab yourself a beverage, sit down in a comfortable spot, and enjoy this manual. I'm not kidding, either. The manual not only tells you how to accomplish things, but it gives background information on battery and charging theory.


On the page that tells about discharging NiCd and NiMH batteries, there is a five-step process that is outlined. But off to the side is the nice little notes section.

One of the notes says: "To determine the condition of a battery, compare the final capacity measurement the battery delivered during discharge to the capacity rating listed on the battery's label. If a battery provides less than 70% of its rated capacity it may need to be replaced. Additional cycles can be attempted to try and revive the battery, but if capacity measurements fail to improve, the battery should be replaced."

There are lots of other nuggets of useful information packed into this manual. It's worth keeping, as it's like a Cliffs Notes version battery & charging theory. Maybe I am stressing this a little too much, but such good manuals are extremely rare these days, and it is one feature that you cannot get an idea about by reading the specs.

Build Quality


I was impressed with the build quality of this charger from the get-go. There are a lot of nice little details.

  • The main chassis is of extruded aluminum with a lot of ridges. The ridges give more surface area, which dissipate heat more effectively than a smooth surface. There are also ventilation holes directly above the main heat-dissipating components, the FETs. (see photos below)

  • There is a strain relief bushing on the input leads, which will protect the internal connections in case the charger should accidentally hang from its leads. (not recommended)
  • The membrane buttons are extremely durable, and do not let dirt in around their edges, like conventional buttons do.
  • The 10 A automotive-type fuse will be easy to replace in case you do manage to blow the fuse.

  • The brushed finish will not show minor scratches and dings like a non-porous finish would.
  • The battery clips are actually big enough to clip onto the terminals of a full-size automotive or marine battery. Kudos!
  • Attractive and easy-to-read color scheme
  • Super-loud beeper can be heard from the other side of your house in case of a fault or when the batteries are done charging.
  • Charger carries the 'CE' Mark. This is a self-declared safety mark in the European market. In order to declare this, the manufacturer needs to have test data proving that the unit was actually tested to certain standards. A certain level of build quality is necessary in order for the unit to comply with these requirements. In the American RC hobby market, safety marks are optional. I'm glad to see that some companies are taking it seriously.


There's really nothing significant here to point out. As a UL employee, I'm fussier than most about electronic design.

These were my two minor nitpicks...

  • The banana jacks are a nice beefy type that are hard to miss. However, the leads interior to the charger that are soldered to these jacks are only tack-soldered. The better way would have been to make the connection mechanically before soldering. This will never become an issue unless the charger suffers a lot of vibration and shocks; however, if it does, those connections may break loose. As a UL engineer, I would prefer to see a mechanical connection made before the solder connection.
  • There are a couple of spots on the solder side of the printed wiring board where solder connections were made without cleaning off the soldering flux afterwards. Soldering flux can degrade the connection over time. Most high-end electronics are washed clean of all soldering flux before final assembly.

To be fair, I'm sure there are a great many chargers that have either or both of these slight deficiencies. Probably all of mine, hehehe.


I found the accuracy of the built-in meter to be very good. The voltage, current, and mAh readings were right on the money, when checked with my professional-grade Fluke 79 multimeter.

For the record, I conducted all testing alternating through the following battery packs:

  • An 8 cell, 3600 mAh NiMH pack
  • An 8 cell, 700 mAh NiMH pack
  • A 3S2P 4200 mAh LiPo pack
  • A 3S1P 1570 mAh LiPo pack

    The only real discrepancies between the actual value as measured by my Fluke 79 and the displayed value as shown by the Jr. were due to truncating and rounding errors. The Triton Jr. didn't care what type of cell chemistry it was working with, it was equally accurate between each type that I tried. (I tried every type except Lithium Ion and NiCd, as I don't have any of either type of battery)

    Note: The basic DC accuracy of my Fluke 79 DMM is 0.3%.

    Mode:Value displayed by Triton Jr. Value as measured with Fluke 79 DMM Percent Error
    Discharge:0.4 A 0.488 A 22% (truncated decimal/rounding)
    Discharge:10.48 VDC 10.50 VDC 0.19%
    Charge:5.0 A 4.93 A 1.4 % (bad rounding)
    Charge:10.53 VDC 10.51 VDC 0.19%

    The mAh readings are calculated from the time and current measurements. I suspect it uses more decimal places than are displayed on the screen. The truncating and rounding errors noted above are probably only because the display only has enough room for so many characters. It's preferable to truncate the precision of certain readings in order to show more readings.


    I found that after charging about 3 batteries of different types & sizes, I had the operation of the charger and its menus memorized. The menus are laid out in an intuitive manner, and I suspect most users will find this to be true. Especially noteworthy is the fact that in order to start charging or discharging, the user has to hold the ENTER/START button down for a full second. What this means to the user is that he can fiddle around and push buttons until he has taught himself how it works. As long as he doesn't hold the ENTER/START button down or reverse the polarity of the input leads, no damage can be done. There was no need for me to run and get the manual every time I forgot a key sequence. I could just fiddle a bit until I "remembered" how it was done. I suspect many of us do our best learning in this manner.

    The charge or discharge settings are all shown on the screen before operation can begin. If one makes a habit of double-checking this information before pressing and holding the ENTER/START button, one will never damage any battery packs. (Watch the video attached below, and you will see what I mean. There were a couple times during its making that I was talking too long, and it saved a setting I didn't want. It was only a matter of a second or two before I was back in the menu, fixing everything for the example.)

    The other day, I was flying my planes while I had two other batteries charging back at the car, some 40 paces away. When the battery on the Triton Jr. was done, I could hear the beeps. This is no small feat on a flying field with lots of glow planes! My other charger, (a Multiplex LN-5014) though it sounds loud enough at home, could not be head at this field.

    This is really an ideal field charger. It does everything that's needed, in one small package.


    One of the things that makes this charger lighter and more compact than its bigger brother is the fact that it does its job without a cooling fan. So naturally, I was curious as to how well the little aluminum chassis would dissipate the heat, and how hot to the touch it would get. The worst-case scenario is when the charger is set to charge at more than 63 W or discharge at more than 5 W. (Yes, 5 W; this is not a fast discharger, just a fast charger!) In either case, the charger's microcontroller will limit the power by reducing the current until the power is at its maximum. Also in either case, the charger body got hot enough that you quickly notice that its on the hot side of warm. I measured it to be 113F (45C). At first, I was a little surprised at this, but then I realized that the designers of this charger chose the power limits based on how hot the chassis would get. It is warm enough that I noticed, but not even close to warm enough to burn me. If you're really in a hurry to discharge, an experienced RC modeler can surely think of non-harmful ways to discharge batteries quickly, right?

    This is the main reason that the Triton or Triton 2 will charge and discharge to higher power levels. The cooling fan makes the difference. However, they are bigger, heavier, louder, and more complex, so choose your charger based on your own priorities.

    I cycled my two big 8 cell, 3600 mAh NiMH packs for a couple hours at a time, to see how the charger would stand up to continuous operation at its power limit. It didn't miss a beat. It sat there, nice & warm, but never shut down.

    Error Detection

    The Triton Jr. will detect a reverse polarity battery pack plugged into its output. It will then warn you by of very loud beeps and a text message on the display. (see video)

    If the circuit is opened during charging, either because a cell went bad, a connection was broken, or a balancer opened the circuit, the Triton Jr. will let you know.

    If the input is hooked to its 12 V source in reverse polarity, the automotive cartridge fuse will blow; there is no electronic polarity protection for the input. These fuses are easily found at hardware and auto parts stores for cheap. I don't consider this a drawback, since it is typically a mistake that is only made once.

    Comparison Table: Triton Jr. vs. Triton 2

    Triton Jr. Triton 2
    Input Voltage: 11-15 VDC 10-15 VDC
    Input Connections:- Banana plugs w/ mating alligator clips
    Number of Outputs:1 1
    Battery Types, No. of Cells:1-14 NiCd/MH, 1-4 LiPo/Io, 2, 4, 6, 8, 10, 12 V Pb 1-24 NiCd/MH, 1-5 LiPo/Io, 2, 4, 6, 8, 10, 12 V Pb
    Fast Charge Current:0.1 - 5.0 A NiCd/MH (63 W max); 1C rating for LiPo/Io (63 W max) 0.1 - 7.0 A linear NiCd/MH; 1C rating for LiPo/Io; 0.1 - 7.0 A for Pb (90W max)
    Fast Charge Termination:"Zero DeltaV" peak detection (NiCd/MH), "CC/CV" for LiPo, LiIo, Pb "Zero DeltaV" peak detection (NiCd/MH), "CC/CV" for LiPo, LiIo, Pb, optional thermal cutoff for all battery types
    Peak Sensitivity:NiCd: 8 mV fixed, NiMH: 5 mV fixed NiCd: 5-20 mV, NiMH: 3-15 mV
    Peak Delay at Start:- 0-60 minutes
    Trickle Charge Current:Charge Current / 20 (NiCd/MH only) 0-250 mA (NiCd/MH only)
    Fast Charge Safety Timer:NiCd/MH: 1.5 hours, LiPo: 2 hours 0-990 minutes
    NiCd/NiMH Max Charge Capacity:100 - 5000 mAh 100 - 9900 mAh
    NiMH Top-off Charge:- 0 - 1000 mAh
    Thermal Cutoff:- 50 - 150 F w/ optional thermal probe
    Discharge Current:0.1 - 1.0 A (5 W max) 0.1 - 3.0 A
    Cycle Count:1 - 5 cycles (NiCd/MH only) 1 - 10 cycles (NiCd/MH only)
    Cycle Time Delay:0 1 - 60 minutes
    Battery Memories:- 10
    Programming Controls:4 membrane pushbuttons modified job dial, 2 pushbuttons
    Display Type:2 x 16 LCD w/ blue backlight 2 x 16 LCD w/ blue backlight
    Displayed Info:Output voltage, charge & discharge capacity, currents & time, errors Input & output voltage, peak voltage, average discharge voltage, charge & discharge capacity, currents & time, data for 10 cycles, errors
    Audible Indicators:Beeper 10 melodies, on/off
    Output Connections:banana jacks banana jacks
    Case Material:extruded aluminum extruded aluminum
    Cooling System:chassis as heatsink built-in cooling fan
    Current Overload:solid-state solid-state
    Case Size:4.7 x 3.6 x 1.2" (118 x 92 x 30 mm) 6.2 x 4.0 x 2.0" (157 x 102 x 51 mm)
    Weight:13.1 oz. (371 g) 16.4 oz. (466 g)
    Street Price (as of October 16, 2006):$90 $125

    A brief list of menu displays (and what they mean, when not obvious)

    Display Meaning, if not obvious
    Pb Charge Charges Lead-acid type batteries, such as field batteries
    Pb Discharge -
    NiCd Charge -
    NiCd Discharge This menu is reached by pressing the 'DEC' key from the NiCd Charge screen
    NiCd CHG to DSCH Cycles the pack, finishing in the discharged state. The number of cycles, charge, and discharge currents are also selected on this screen. Press the 'DEC' key from the NiCd Discharge screen to get here.
    NiCd DSCH to CHG Cycles the pack, finishing in the charged state. The number of cycles, charge, and discharge currents are also selected on this screen. Press the 'DEC' key from the 'CHG to DSCH' Discharge screen to get here.
    NiMH Charge -
    NiMH Discharge -
    NiMH CHG to DSCH same as is described in the NiCd row above
    NiMH DSCH to CHG same as is described in the NiCd row above
    LiPo Charge Press the 'DEC' key from here to get to 'LiPo Discharge' and 'Lithium Type' screens
    LiPo Discharge -
    Lithium Type Once here, press 'ENTER' then 'INC' or 'DEC' to choose the type of lithium cell you'll be charging. Most of us will just leave it on LiPo and never look at this menu again.



    This is a full-featured computer charger in a pint-sized package. It is truly a portable size and will fit in most small field boxes. It seems about 50% thinner than the original Triton. Note that the original Triton has a cooling fan, so it will support faster discharge rates than the Triton Jr. The trade-off is that it's bigger, noisier, heavier, and has moving parts that can eventually fail. This is a solid little computer charger, which is easy to use. It should be quite reliable.


    • A great size
    • A great price
    • Tons of features


    • No charge lead or banana plug is included. Electrifly cannot predict what type of plugs we all use on our batteries. But it would've been nice for them to at least include a couple of leads with banana plugs on one end that would plug into the charger. The end user could then solder his own choice of plug at the other end to mate with this battery packs.
    • The beeper is super loud. This can be either bad or good. Bad, if you're charging batteries in the next room while the family's trying to sleep. Good, if you charge your batteries in a noisy environment.

    Editor's Note: For safety reasons, it is ALWAYS best to stay near your batteries while charging, to watch for problems that could arise.

    Last edited by AMCross; Nov 15, 2006 at 02:18 PM..
  • Thread Tools
    Nov 10, 2006, 05:02 PM
    Test your IMAC!!
    sun.flyer's Avatar

    Nice work on the review!! Excellent detail on what this charger is capable of. Thanks

    Nov 10, 2006, 05:14 PM
    dave49749's Avatar
    Nice job I have a brand new JR. Thanks
    Nov 11, 2006, 12:39 AM
    Registered User
    Excellent review! The info presented is a great help.

    Greg S

    <edit> update - bought one today - review was deciding factor </edit>
    Last edited by SundayFlyer; Nov 11, 2006 at 05:20 PM.
    Nov 11, 2006, 01:39 AM
    Registered User
    Looks like the old fma direct charger... only this one says GP

    Good review, thanks for whipping out the Multimeter.
    Nov 11, 2006, 05:33 AM
    The Lipos cost how much?!
    pumi's Avatar


    Looks like they took a normal triton and threw it into the old FMA SuperNova case....

    Pretty nice though.

    Nov 11, 2006, 11:25 AM
    Senior User
    Jeremy Z's Avatar
    Originally Posted by lvmike
    Looks like the old fma direct charger... only this one says GP
    I am seeing a LOT of chargers that I suspect have nearly identical electronics. My first charger was a Multiplex LN-5014, which also looks the same. The Multiplex has a green backlight which is just slightly easier to read, smaller, electronics style alligator clips for the input, (not good for clipping onto car battery terminals) and the beeper is only half as loud. The styling is also half as loud. It also doesn't limit the charge time.

    The Hyperion clone of this charger doesn't support LiIo batteries; not a huge deal for most of us, but worth noting. I don't know if it has the charge timers.
    Nov 11, 2006, 01:48 PM
    Molon labe
    Red Scholefield's Avatar
    Great job on the review, one of the best I've seen. I wish someone would do an honest one on the MRC 989 just out. The one in RC Flyer (Jan-07) is nothing more than a rewrite of the manufacturer's promo material. Nothing of any technical substance.
    Nov 11, 2006, 04:47 PM
    Registered User
    Probedude's Avatar
    Thanks for the review and ESPECIALLY for the internal pictures on its construction/board layout!

    Given the CE marking, can you tell if this unit is RoHS compliant? (since Europe is ahead of us in this area)

    Edit: Just looked at the HobbyLobby website and they have another charger that looks the same as this one. Scroll down to the Simprop
    Last edited by Probedude; Nov 11, 2006 at 07:43 PM. Reason: Question on UL #
    Nov 12, 2006, 09:11 PM
    Senior User
    Jeremy Z's Avatar
    Originally Posted by Red Scholefield
    Great job on the review, one of the best I've seen. I wish someone would do an honest one on the MRC 989 just out. The one in RC Flyer (Jan-07) is nothing more than a rewrite of the manufacturer's promo material. Nothing of any technical substance.
    Red, I was curious about that too. I just saw a one page "review" in Quiet Flyer myself. It talked about the capabilities of the charger, some of which were interesting. I wouldn't mind reviewing it myself, if it becomes available for review.

    Some previous MRC chargers had gotten a reputation for not being suitable for charging LiPos. I'd like to see if they've got that problem licked.
    Nov 14, 2006, 01:38 AM
    Suspended Account
    scratchandbash's Avatar
    On the "weakness" issues, concerning internal bananna jack soldering:
    The one thing that always gets me, is when they won't twist the wires before tinning and/or slodering to the connector. They always miss this with voltmeter leads too. A little bit of repeated motion, and all the wire strands eventually break.

    I guess it adds a second or so of manual effort to the assembly process, after stripping wires.

    As for "what they mean by, but not obvious", I found that when I was working in technical writing, that I had to proof my material a day or so later, and attempt to "dumb down" my mind, as If I had no prior knowledge of the product. Amazing how you can actually fail to understand your oun literature, when looking at it in this light. Helps a lot in the editing process.

    Like giving directions to folks, 90% of people are simply telling themselves how to get there, which they already know.

    As for Electrifly:
    I finally used my GP balancer with my Power Series 3s-2100. Seems to work fine in conjunction with my vintage Kokam charger.
    Last edited by scratchandbash; Nov 14, 2006 at 01:45 AM.
    Nov 14, 2006, 06:40 PM
    Registered User
    Kev71H's Avatar
    I love my TRITON Jr!!!!!!!!!!
    Nov 15, 2006, 01:41 PM
    dave49749's Avatar
    Excellent review and presenting of the information on the JR
    I just returned to the hobby and purchased a JR and for my RX and smaller Lipos it performs great.
    Nov 17, 2006, 01:24 AM
    rpage53's Avatar
    I didn't see the SJ on the board but a lot of these chargers (Simprop Intellicharge, FMA SuperNova, Graupner Lipo4, Polycharge, Ripmax, Swallow, ...) are made by Sung Ji in Korea so they share similar features. I assume this one is too.

    Nov 26, 2006, 07:00 PM
    Registered User
    How do people use this charger when indoors? Do you hook the clips to the ends of the transformer wires? That seems sort of cludgy and potentially dangerous, so Im thinking about adding a connector between the clips and the charger so I can switch between the clips and transformer.

    Has anyone done this? Any reason not to use a transformer as input?

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