Graupner SJ Polaron EX Charger - Review - RC Groups

Graupner SJ Polaron EX Charger - Review

Editor Matt Gunn takes a close look at this unique smart-charger.

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Introduction

Product:Graupner/SJ Polaron EX
Retail Price:$319
Max output:800w
LCD screen:3" touch screen
Input power:12v - 24v
Available from:OpenHobby.com

The Polaron EX from Graupner SJ is an 800w 2-port smart-charger with a unique vertical case design and touch screen interface. The Polaron EX has a number of features aside from charging that make it appealing to hobbyists in different segments; from servo testing and battery and tire warming, to esc programming and motor break-in cycling, the Polaron EX is truly the jack-of-all-trades of microprocessor-controlled chargers.

In this review, we will explore some of the various functions, screens, and go through a standard charge cycle with a 3s 1300mAh LiPo. Let's take a closer look at the Polaron EX charger.

What's Included

The Polaron EX is one of the more unique designs I've seen; the case stands vertically and has a smaller footprint than the majority of chargers available, making it great for smaller workbenches or setting up in the pits where your space can be limited. Although the Polaron has that metallic look to it, the entire case is plastic and feels quite sturdy.

There's plenty of connection points on the Polaron EX, so lets start with the back. In the middle of the case, between the two fans, are a pair of banana plugs for 12-24v dc input. In the left side of the case are another pair of banana plugs. These plugs are an additional 12-24v input and are designed for the 12v power supply that has the same form factor. Since I dont have it and I love my Titan PS from RCAccessory.com, I'll be using it in this review. Moving up top, there's a mini usb port for firmware updates or using the computer software that can monitor charge operations.

On the right side of the Polaron's case are four connection points. At the top right is a 5v 2.5 amp usb port for charging or powering equipment that uses a usb. At the bottom left is an telemetry hookup for programming esc's with telemetry capabilities. Next is a motor sensor port for break-in and testing of brushed motors. Last on the list is an output for testing servos.

The front face of the Polaron EX houses a 3" touch-screen LCD display, two pairs of female bullet connectors for charging, and two balance ports. In the middle of the face is a blue back-lit button that switched between channel 1 and channel 2. At the bottom of the face are two servo-style connectors for using the included temperature sensors.

Graupner SJ has included with the Polaron EX two pairs of output charging cables with alligator clips, two temperature sensors, two balance boards (up to 7-cell), a usb cable, and a positive/negative cable with bullet connectors for supplying power from your power supply to the Polaron. The first thing I did was remove the alligator clips and install some XT60 leads... my connector of choice.

For charging in the field and using a car battery, a pair of large alligator clips are included as well.

Touch Screen Interface, Options & Features

The Polaron EX is quite easy to use once you take a few moments to explore its functionality and order of operations. I'm coming off of an Hyperion EOS 0610i Duo II charger so naturally I compared the Polaron's usability, navigation, and functionality to the Hyperion. Both take a few steps to initiate a charge, but the Polaron has one or two extra required button pushes, depending on what you're doing. I really like the 40 model memory and the ability to name the charge preset, a function not offered on the Duo II. I do have a couple of minor issues with a few screens, but we will discuss that below. Let's examine the 3" color LCD screen.

The color LCD screen is touch sensitive and contains eight apps; anyone with a smart phone should instantly feel at home with the layout. Pressing any of the square apps will take you into that application and allow you to make adjustments and use the app. For instance, pressing the Profile app will bring you to a battery profile page. You can scroll through the profiles, select one, and change parameters. Press the Misc. app, and you will go into the additional features offered by the Polaron such as tire warmer, servo tester, etc. At any time, you can move to the next available screen within each app my pressing the up or down arrows, or return to the homepage by pressing the back arrow.

The screen takes up as much real estate as it can on the face of the Polaron EX, but it's still a 3" touch-screen display. This means that if you have fat fingers, chances are you will press the wrong button from time to time. Luckily, a plastic interface pen is included and snaps into the right side of the case at the top. It's functions the same as a touch-screen pen at a checkout or a smart tablet.

Channel 1 and channel 2 work independently of each other, and each channel has the full eight apps; select between the two channels by either pressing the blue back-lit button in the middle of the face, or choose the desired channel at the bottom of the LCD screen.

The Apps:

Profile

The Profile app is where you chose the battery charge preset. As with most microprocessor controlled chargers, you can choose between battery type, voltage, and capacity in milliamps. You can also name your battery preset. Missing from this page is a charge rate selection in amps. This is because the Polaron defaults to a charge rate equal to the packs amp-hours, or it's 1c rating. This is pretty standard stuff; if the pack is 1300mah, or 1.3ah, then it will start the charge out at 1.3 amps. Once charging, you can adjust the c rating as we will see below.

Charge

The Charge app opens to the last selected preset in the Profile app. From here, a single push of the right arrow at the bottom of the screen allows you to select what type of charge you want to start. Since we are using a LiPo battery for the review, you can choose between the following charge types:

  • CC/CV (constant current, constant voltage): The standard for charging LiPo batteries.
  • FAST: similar to CC/CV, the charger first charges with a constant voltage, then a constant amperage to quickly top off a pack.
  • N-STORE: Normal charge/discharge for long term storage.
  • Q-STORE: Quick charge/discharge for long term storage.
  • CV-LINK: Used to connect multiple packs of the same voltage and amp hours in series.

When you've chosen your charge type, the next screen allows you to adjust maximum cell voltage, charge current (defaults at 1c), maximum cut-off temp (if using the temp sensor), maximum capacity, the safety timer, and if you are storing the pack, the storage voltage. Pressing the arrow button from here initiates the charge sequence, verifies the cells and correct voltage, and begins charging.

Discharge

The Discharge app and the N-STORE (storage) option in the Charge app are very similar; they will both discharge your pack to a preselected voltage per cell. The difference is that if the pack is below the preselected voltage, N-STORE will charge it up to the preselected voltage. Discharge will not. I have not used the Discharge app but to test it only. If I'm ever discharging a LiPo pack, it's for storage, so I use the N-STORE selection in the Charge app.

Cycle

The Cycle app will benefit NiMh and NiCd batteries that can develop a memory from incomplete charge/discharge cycles. LiPo's don't develop a memory, so this function will not be tested in the review. However, for NiMh and NiCd, they procedure is similar to what is described in the Charge app above; initiate the cycle by pressing the arrow on the bottom right, and the Polaron EX will charge and then discharge the pack.

Balance

The Balance app does exactly what it says: balance LiPo, Lilon, LiFe packs. At any time while in the app, pressing the right arrow will initiate a balance procedure and bring all cells to the same voltage without fully charging the pack. There are 3 screens to chose: screen 1 shows the current state of the pack (number of cells, average voltage, gap voltage, high and low cells), screen 2 shows the cell voltage and internal impedance values, and screen 3 displays cell voltages in a bar graph reading.

Data

The Data app consists of 3 screens. The first screen shows a real time display of the input/output voltage, temperature, resistance of battery. The second screen displays cycle data after cycling a battery. The third screen shows data similar to the first page, but in graph format.

Misc

The Misc. app has four functions, mostly designed for rc vehicles and racers. The servo tester function however, is great for anyone wanting to center a servo before installation in an airframe or chassis, and testing the end points of a servo. The second function is a brushed motor tester and conditioner. For those running stock classes such as the Tamiya TCS Mini series, where brushed motors are utilized, this function can help break-in a motor and bed in the brushes. The next function is a tire and battery warmer. You'll need to supply your own battery/tire warmer bag as it's not included. Finally, an esc programmer function allows you to adjust the parameters of an electronic speed control with a telemetry port. Unfortunately I don't own a brushed motor, lipo heater, or an esc with telemetry. I do have plenty of spare servos, and I'll go over this tester in the video portion of the review.

User Set

The User Set app contains all the adjustment points for the Polaron EX's operations. The first screen allows the adjustment of charge-complete tones, length of the tone, beep on/off, LCD brightness, temperature scale, and volume. The second screen allows you to change the maximum watts per input and output. For instance, you can allot almost all of the available 800 watts to one output channel to charge at higher c ratings than you would if the wattage was split between both channels. The third screen has date/time adjustment and two alarms. The alarms could be handy to alert you of a scheduled heat race or event when in the pits. The fourth and final screen in the User Set app adjusts the user name and language, and a button called Option. However, there seems to be a bug in this page because all buttons take you to the user name function only.

Charging Cycle

The photos below are a progression of a typical LiPo charge session. Please watch the video portion of the review where I explain the process in detail.

Conclusion

The Polaron EX from Graupner/SJ is a dual port charger with enough output power to charge large packs quickly and safely. The 3" LCD screen is easy to use without too many accidental hits; fat-fingered users will appreciate the included push-pen to keep accidental hits down to a minimum. The navigation and order of operations to initiate a charge is very easy to get through. I do like the vertical design of the Polaron EX, but I'm still looking for a charging case that can accommodate its design without having to lay it down sideways.

One area that needs attention is a couple of bugs in the software. The Profile app has two instances of the battery profile on the same page and really only needs one. The fourth screen of the User Set app has three buttons, and all of which take you to the same "name" screen to customize your name in the charger. Lastly, I was hoping for a percentage of charge display somewhere in the charger as I have become a bit spoiled with my Hyperion Duo-II charger and Sentry battery checker that show the batteries current voltage as a percentage. This last statement is a personal opinion of mine, and I realize other users are fine without the percentage being shown.

Aside from a few interface issues, I'm perfectly happy using this charger over my trusty Hyperion Duo-II which has served me well for years. Thanks for reading my review, and happy charging!

Last edited by Matt Gunn; Sep 08, 2014 at 09:39 AM..
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Sep 08, 2014, 10:30 AM
God is Good
TMAC4123's Avatar
Looks very nice!
Sep 08, 2014, 01:51 PM
urs
urs
Registered User
a bit too much money ...agreed its good well thought out but I prefere to get a cheaper, just as powerfull one and buy some lipos with the spare cash....hey I love flying .
urs------switzerland---
Sep 08, 2014, 04:01 PM
Registered User
So you can't program or setup charge and discharge cycle for LiPo break in? Typically do 3 cycles at 1C to break in a LiPo. No sure if it works but seen others recommend breaking in a LiPo that way.
Sep 08, 2014, 04:21 PM
Registered User
I'm with you on seeing a percentage; if it's accurate, that's what I like to go by: but I'm not a techie, and can never remember what the required voltages are!
Sep 08, 2014, 04:47 PM
RCGroups Editor
Matt Gunn's Avatar
Quote:
Originally Posted by RyanFromYEG
So you can't program or setup charge and discharge cycle for LiPo break in? Typically do 3 cycles at 1C to break in a LiPo. No sure if it works but seen others recommend breaking in a LiPo that way.
Yes, you can easily cycle LiPos with the Polaron.

I just spoke of the NiMh benefit in the review. I've never really cycled LiPos and read many places that it doesn't benefit the packs.
Sep 08, 2014, 06:56 PM
Recon 7
swollencranium's Avatar
Holy crap that thing is Sexy !!
Sep 09, 2014, 10:46 AM
Registered User
JustPlaneChris's Avatar
Matt, can you clarify something for me?

You mention that the charge rate is by default set to 1c when you configure a battery profile. Is there no way to save a 2c charge rate without "lying" to it about the battery size?

Thanks!

Chris

PS: I thought of another question: From the pictures it looks like the balance board plug is non-standard (not like the plugs on the popular parallel charge boards for example). True?
Last edited by JustPlaneChris; Sep 09, 2014 at 10:58 AM.
Sep 09, 2014, 03:01 PM
Autopilot no control
I concur the sexiness of this device! I just want one as desk decoration.
Sep 10, 2014, 09:14 AM
RCGroups Editor
Matt Gunn's Avatar
Quote:
Originally Posted by JustPlaneChris
Matt, can you clarify something for me?

You mention that the charge rate is by default set to 1c when you configure a battery profile. Is there no way to save a 2c charge rate without "lying" to it about the battery size?

Thanks!

Chris

PS: I thought of another question: From the pictures it looks like the balance board plug is non-standard (not like the plugs on the popular parallel charge boards for example). True?
Hi Chris,
you can change the charge rate before you start the charge easily, no need to trick it. After pressing the charge app on the main screen, just press the current button and chose your amperage, then commence the charge.



Yes, the balance leads are proprietary where they go into the charger.

Matt
Sep 11, 2014, 09:09 AM
Electric or Bust!
skyjet's Avatar
Great review Matt! I read every word and watched the video. I have 3 EX chargers and have one issue that drives me crazy that no other charger I've ever owned has done. I would love your feedback because you also have used Hyperion. I copied and pasted this from another thread.


I thought I would check in here and update my thoughts on the Polaron EX. I've been using three Polaron EX chargers for the last 3 months along with a Hyperion EOS720i Super Dou 3 I've been using for a couple of years. I use my chargers almost every day. Both chargers charge the batteries the same but it takes several more inputs to get the batteries charging on the Polaron EX. I can get my batteries charging in about a quarter of the time with the Hyperion. With this said, I do still recommend the EX because of its "cool factor" and it doesn't take up as much room on the work bench and I'm sure the problems can be fixed with a firmware update. It doesn't seem that Graupner is working on updating the EX but is just releasing updates for their radio line.

This is an example of what needs to be updated. All chargers that I've ever had would always stay on the last memory used when you turn them off but the Polaron EX always goes back to a default memory when you turn it off. The default is different on each charger. I fly RC airplanes and only charge LIPOs. The day I fly, I charge up the batteries that I plan on using and as soon as I get home I put all of the batteries on a storage charge. When I get home and start my Hyperion I just have to push 3 buttons to put my batteries on storage charge but with the Polaron EX, I have to push as many as 16 buttons to get the batteries on storage charge. I find I use the Hyperion more often because it is easier to use.

I'll explain: Say the chargers default memory is 1 and the memory I'm going to charge and store my batteries at is memory 10. After I charge on memory 10, I turn off the charger and go fly. When I come home to put the batteries on a storage charge I turn it on and it defaults back to number 1. So in order to start that same battery on storage charge I counted 16 button pushes to do the same thing that 3 button pushes does on my Hyperion or any other charger I've ever owned. I'm sure that could be fixed with a firmware update and hope to see one by the end of the year.

Also on my wish list that would help speed up the process is if the EX had a button on the main page for "Storage" charging that would also bypass some of the button pushing.

Thanks for reading!
Sep 11, 2014, 09:37 AM
Suspended Account
Hi.. what is the maximum and minimum voltage I can adjust per cell.. IE.. 4.20 volts
at this price I would hope a brushless motor tester would have been in this do you know if its in plans or future upgrade ?
Sep 11, 2014, 12:54 PM
Graupner USA's Avatar
Quote:
Originally Posted by skyjet
Great review Matt! I read every word and watched the video. I have 3 EX chargers and have one issue that drives me crazy that no other charger I've ever owned has done. I would love your feedback because you also have used Hyperion. I copied and pasted this from another thread.


I thought I would check in here and update my thoughts on the Polaron EX. I've been using three Polaron EX chargers for the last 3 months along with a Hyperion EOS720i Super Dou 3 I've been using for a couple of years. I use my chargers almost every day. Both chargers charge the batteries the same but it takes several more inputs to get the batteries charging on the Polaron EX. I can get my batteries charging in about a quarter of the time with the Hyperion. With this said, I do still recommend the EX because of its "cool factor" and it doesn't take up as much room on the work bench and I'm sure the problems can be fixed with a firmware update. It doesn't seem that Graupner is working on updating the EX but is just releasing updates for their radio line.

This is an example of what needs to be updated. All chargers that I've ever had would always stay on the last memory used when you turn them off but the Polaron EX always goes back to a default memory when you turn it off. The default is different on each charger. I fly RC airplanes and only charge LIPOs. The day I fly, I charge up the batteries that I plan on using and as soon as I get home I put all of the batteries on a storage charge. When I get home and start my Hyperion I just have to push 3 buttons to put my batteries on storage charge but with the Polaron EX, I have to push as many as 16 buttons to get the batteries on storage charge. I find I use the Hyperion more often because it is easier to use.

I'll explain: Say the chargers default memory is 1 and the memory I'm going to charge and store my batteries at is memory 10. After I charge on memory 10, I turn off the charger and go fly. When I come home to put the batteries on a storage charge I turn it on and it defaults back to number 1. So in order to start that same battery on storage charge I counted 16 button pushes to do the same thing that 3 button pushes does on my Hyperion or any other charger I've ever owned. I'm sure that could be fixed with a firmware update and hope to see one by the end of the year.

Also on my wish list that would help speed up the process is if the EX had a button on the main page for "Storage" charging that would also bypass some of the button pushing.

Thanks for reading!
Points well taken and valid. Those and many others have been placed on the R&D request list.

I always smile when being compared with Hyperion
Sep 11, 2014, 01:16 PM
Electric or Bust!
skyjet's Avatar
Quote:
Originally Posted by Graupner USA
Points well taken and valid. Those and many others have been placed on the R&D request list.

I always smile when being compared with Hyperion
Thanks for the reply. Any word on when we can expect a firmware update?
Sep 11, 2014, 01:19 PM
Electric or Bust!
skyjet's Avatar
Quote:
Originally Posted by Graupner USA

I always smile when being compared with Hyperion
These changes will have the EX pass up Hyperion!
Last edited by skyjet; Sep 11, 2014 at 02:28 PM.


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