GREAT PLANES TRITON
A versatile computerized peak charger, discharger and cycler that's LOADED with features!
Review by John Tracey RCEFLYER@jtinct.rchomepage.com
Distributed by Great Planes
Suggested retail: $129.99
Great Plane’s Electrifly division released the Triton last year just about the time the new lithium polymer batteries hit the market. It has been time tested for over a year now and is still one of the best selling chargers on the market. After reading this review you will understand why.
The Triton Charger has the highest number of features for the lowest cost as compared to other chargers of this type. The Triton’s most notable feature is that has the ability to charge four different battery chemistries including Lithium ion polymer and the lead acid batteries we usually use a primary batteries. This charger also is capable of NiMH and NiCd charge/discharge cycling and can memorize the results of up to ten of these cycles. The Triton is more of a battery manager than just a battery charger.
The features of this charger are so abundant that it is easiest to categorize them in their uses and then list the features.
Now that I have listed the features of this charger I will continue my review by describing the mechanics of the charger, the instruction manual and how a few of the functions are used as I go into detail about how specific batteries are charged. I think that an understanding of how different types of batteries are charged is important to gain the most from all of the features of this charger.
The Triton charger connects to the primary source with large clips and uses banana jacks for the connection to the battery being charged. The triton has a two line LCD that displays data relevant to the menu you are in. There are two push buttons labeled Menu and Battery Type and a dial jog shuttle push button. These easily allow you to access and navigate through the menu structure to change any of the settings needed for your battery requirements. The Menu button allows you to access different sections of the main menu. The Battery Type button allows you to access each of the four battery types, plus the 10 user programmable memories. The jog shuttle dial allows you to dial through each setting in each menu and make changes. The controls on this charger are the easiest to use and find my way around in of any of the highly featured chargers I have used.
The instruction manual is not difficult to follow but there is a lot to understand. One thing I have come to realize is that the more features you get in a charger the more complicating it is to learn and to use. The manual does a pretty good job of sorting out the different functions of the charger and describing how to use them. The first page of the manual is quick reference guide for easy access to key information. Five pages of flow charts also help to learn the specifics of the charger. The manual goes into detail on how to charge each type of battery and describes how to use each of the functions. A trouble shooting section is included at the end to aid in any trouble you find yourself in. The full instruction manual can be downloaded from the Electrifly web site here. MANUAL
The Triton charges four different battery types. Different types of batteries have different chemical make-ups that cause them to function differently. In most cases the discharge of these different battery chemistries are very similar except each battery type can only be discharged to a certain number of volts per cell. The lithium batteries in particular will not recover from a discharge of more than 2.5 volts per cell. The method of charge for each of these battery chemistries is also different. The charge methods for Lithium are very different than NiMH or NiCd. Improper charging of lithium cells can not just ruin the cells, it can be VERY dangerous.
I will start with the two currently most common battery types, NiMH and NiCd, and explain how they are charged. The Triton uses a delta peak method of charging. This method uses a predictable characteristic of these two battery chemistries to determine when the battery is charged. This characteristic is a delta voltage peak that happens when a cell reaches the top of it’s charge. As the battery charges, the voltage of the battery slowly increases. Once the battery becomes almost fully charged, the voltage increase stops and will slowly start to decrease. This is the delta peak. The Triton charger senses this peak and goes from fast charge to trickle charge. (Top-off for NiMH) At this point the rate of the trickle charge is automaticlly set by the Triton’s programming. This is determined by the rate of the initial fast charge rate. The trickle charge rate is different for either NiMH or NiCd. Refer to the tables on page 9 of the manual to see the trickle charge rate for the initial fast charge rate.
There are a number of features that can be used and parameters that can be adjusted for each of these two batteries.
Lead acid batteries are probably the easiest and most foolproof batteries of them all. These are normally used as primary batteries, power for glow igniters, fuel pumps and glow engine starters. I use the Triton with a power supply to charge my 7 Ah 12 volt battery for the few glow planes I own. I also use it for the large car battery that I use as a primary battery when indoor flying.
The charge method the Triton uses to charge these types of batteries is a constant current /constant voltage method. The voltage (6, 12 or 24 volts) and the current (0.1-5.0 amps) of the battery is selected by the user. The charger then constantly charges at the current setting until the battery reaches the proper maximum voltage. Then, the charger stops delivering constant current and now starts delivering constant voltage. At this point, the output voltage of the charger and the battery voltage are close to equilibrium and so the battery will only take the remaining amount of current that it need to become fully charged. .In discharge mode the charger discharges to a predetermined voltage for each of the three battery voltages.
The Triton charges both the old type lithium and the new lithium ion polymer cells. These new polymer cells, often referred to as LiPo cells, have had an incredible impact on the concept of electric power flight as a whole. This new type of battery chemistry has evolved very quickly and is still evolving. The first LiPo cells were introduced at the end of the summer of 2002. This was right about the time that Great Planes introduced the Triton charger. Great Planes had the foresight to design their charger to be compatible with the new technology LiPo battery in every way. The Triton is still the most advanced charger to include lithium capability anywhere near it’s price range. The only change I would like to see is if they could increase the maximum charge current to above 2.5 amps for large capacity, parallel pack configurations.
The charging method and use of lithium batteries is different than any of the other types. There are a few things to understand about lithium batteries and how charge/discharge rates are determined that I want to take the time to explain before I discuss how the Triton charger works in lithium mode.
First I want to be sure everyone understands what C means. C is the number of amps that a specific battery will deliver for exactly one hour. The mAh rating comes directly from the C of a specific battery or cell. For example a cell in a 1200 mAh battery has a C rating of 1200mA. If one were to charge this cell, from a complete discharge, at 1200 mAh (the same as 1.2 Ah) it would take 1 hour to charge. If one drew 1.2 amps from this cell it would take 1 hour to completely discharge it. So, if one drew twice that current, 2.4 amps, the time to discharge the cell would be cut in half. It would be 1/2 an hour. Discharging at 2 times the C rating is 2-C. If one discharges the cell at 3-C it would discharge in 1/3 of an hour or 20 minutes. 4-C would take 15 minute and so on.
Charging a cell works the same way. The C rating is read the same whether you are charging or discharging a cell. Just for reference, trickle charging is commonly done at 1/10-C. A 1200 mAh cell would charge at 120 mAh for 10 hours.
Okay, now that we all know what C ratings are, let’s discuss lithium batteries. Lithium batteries are different from NiMH and NiCd in their nominal voltage. Where NiMH and NiCd have a nominal voltage of 1.2 volts per cell, lithium cells have a nominal voltage of 3.6 volts per cell. The voltage of a typical lithium cell will range from 4.2 voltages at maximum charge down to to 2.5 volts at maximum discharge. It is CRITICAL that these voltage specifications are not exceeded. Battery packs built from lithium cells have voltages that follow 3.6 volt increments. The Triton is capable of charging four of the cells in series and an unlimited number in parallel.
The original lithium cells were not capable of delivering a very high current. The first LiPo cells were capable of delivering 3-C (3 times their capacity). Because these new cells were so light the packs were often built with the cells not only in series but they were put in parallel too. This not only doubled the capacity of a battery pack but it allowed the pack to deliver double the current. This configuration is commonly seen labeled as XSYP or 3S2P ect…. where X is the number of cells in series and Y is the number of cells in parallel. A 3S2P pack built from 1020mAh cell would have a nominal voltage of 10.8 volts and a capacity of 2,040mAh. The newer light weight LiPo technology is now delivering cells that are capable of delivering currents of up to 20-C!
This revolutionary new technology has brought electric flight to a new level, but not without cost. Many modelers over the past year have learned the hard way to respect the unique chemistry of the LiPo battery. History of these cells has shown us that they will catch on fire if they are charged incorrectly. Charging these cells correctly is not difficult but it takes full attention. I cannot stress enough the importance of double and then triple checking your charge settings. Accidentlly charging at too high of a voltage WILL cause the cells to catch on fire. I always charge my lithium cells in a Pyrex™ container and NEVER charge them unattended. I also NEVER charge in my vehicle. Yes, at first glance this type of battery can appear to be a dangerous choice, but with proper education about how to handle and store these cells, the performance and duration of future electric flights will be unmatched.
Electrifly has taken all of mechanical safety precautions available in designing the lithium mode of their Triton charger. The charger can charge up to 4 cells in series at a rate of 0.1 amps up to 2.5 amps. Lithium cells do not peak! The charge method the Triton uses is Constant current / Constant voltage, delivering constant current until the battery reaches a specified voltage (~ 4.1-4.2 volts per cell) and then a constant voltage charge until the cell voltage is in equilibrium with the charger output voltage. During this constant voltage charge the current is determined by the difference in voltage between the charger and the battery. As the voltage difference gets closer to equilibrium, the current naturally drops. When the current reaches a value lower than 0.1 amp, the charger stops charging. The Triton will discharge the lithium cell to 3.0 volts per cells.
It is important to note that the Triton has two voltage settings for each cell count. Lithium-ION cells almost always have a nominal rating of 3.6 volts per cell. Lithium-POLYMERS, however, almost always have a nominal voltage rating of 3.7 volts per cell. As such, if the voltage setting of the battery is based on 3.6V per cell, Triton understands this to be a lithium-ION cell and will automatically set the maximum charge voltage to be very close to 4.10V per cell. However, if the voltage setting of the battery is based on 3.7V per cell, Triton understands this to be a lithium-POLYMER cell and will automatically set the maximum charge voltage to be higher than 4.10V per cell, but slightly lower than 4.20V per cell (for safety). So, keeping in mind how voltage sensitive lithium batteries are, charging a lithium-polymer cell at lithium-ion voltage wouldn't be dangerous (slight undercharge), but charging a lithium-ion at a lithium-polymer voltage would be a slight overcharge. Being as this is a difference of only a tenth of a volt per cell for the lithium polymers and lithium cells have been known to come out of balance, (cells in a pack have slightly different voltages), I recommend using the lithium ION setting (3.6 volts/cell)for both chemistries. This would ensure the greatest safety.
I was very impressed with features on this charger. It does everything I could want a charger to do. One neat feature that I like is it’s 10 battery memory. This can be used for quick setting your most frequently used batteries. Another is the optional thermal probe. This will shut down the charger if the temperature you select is exceeded. I recommend using this when charging LiPo cells. What a great safety feature! One warning I have, applies to all chargers in general. If you use Deans connectors, you will have two exposed leads on the charger. Be careful not to short them! This may ruin the charger.
In my opinion the battery charger is the central piece of an electric modelers flight box. It is the tool that you will use the most and rely on the most. I personally have three chargers I use all the time and a few on my bench I use once in a while. The choice you make when buying a charger should be well thought out. I recommend getting the best charger you can afford. The price on the Triton is not the lowest but the versatility cannot be beat. I can’t think of a better choice for an ALL-IN-ONE charger than the Triton. I highly recommend the Electrifly Triton if you a looking for a mid priced charger. I am sure you will be happy with your choice and the ease of use.---John Tracey