Results 1 to 19 of 19
  1. #1
    RC Racer
    Join Date
    Aug 2008
    Location
    Sherwood Forest, UK
    Posts
    210

    TQI battery pack. Wiring question.

    Can some one please explain this to me, I just don't get it.

    Every battery pack I had in my petrol days has a servo type plug on it. Just like the one in this picture, but without the signal wire of course.



    The traxxas battery pack seems to look the same from this picture.



    So, the center wire is positive & the wire on the opposite side to the tab in negative.
    This makes sense to me so far. When fitted to a receiver, all the red & black servo wires line up with the same colours as the battery pack plug to power them.

    According to the manual, you can plug an RX hump pack into your TQi TX to allow you to use rechargable batteries instead of dry cells. Again, all good so far, 5 x 1.2v batts is the same as 4 x 1.5v batts.

    Now heres the bit I don't get. The plug on my TQi battery pack is wired so that negative wire is in the signal wire hole. Obviously my TQi works like this. I've not seen anywhere that you have to rewire a RX pack before you fit it, so what's going on?

    I know I must have missed something simple, but I just can't see what!

  2. #2
    RC Turnbuckle Jr.
    Join Date
    Dec 2006
    Posts
    4,398
    You're right, Traxxas made a mistake here... If you take a look at these pictures, the negative wire is on the wrong position...





    And, I just checked, the manuals are wrong too... Same pictures on them...

    So, just switch the negative wire to the other position on the hump pack connector and you're good to go...

    But, then you can't charge the pack with an external charger...

    What you can also do is to switch the negative wire inside the TQi connector to the other side, not an easy task really... But, this might void your warranty...

    The right good thing to do here, would be to call Traxxas and have them send you a new TQi...

    And, if you can, email or call them and tell them this, so they are aware of this mistake...

    Last edited by danielhr77; 06-30-2012 at 09:13 PM.
    200, 202, 420, humor 404, 301 to rc10talk, 410.

  3. #3
    RC Champion
    Join Date
    Jul 2007
    Posts
    1,256
    My guess is they did this on purpose as a safety design, and the radio will work with the negative wire in either position. With this design, the external charge jack would be wired to only charge a battery that has it`s negative wire in the proper position, like on the RX pack. By making the dry cell AA holder have the negative wire in the signal wire position, it prevents someone from using the charger port with AA batteries.

    I haven't taken mine apart to look yet but this makes sense, and if I were to design it that's exactly what I would do.
    I need R/Cers anonymous.

  4. #4
    RC Turnbuckle Jr.
    Join Date
    Dec 2006
    Posts
    4,398
    For my, it's clearly a mistake... Both pictures are showing AA and NiMh with the wire on the wrong side...
    200, 202, 420, humor 404, 301 to rc10talk, 410.

  5. #5
    RC Champion
    Join Date
    Jul 2007
    Posts
    1,256
    I just took it apart and I'm correct. The radio will work with the negative wire in either position, but you can only charge through the charge port when it's in the normal position, like on the RX pack. It's preventing you from using the charge port with AA batteries.

    danielhr77, the second picture with the RX pack is wrong, the negative wire should be on the side opposite the tab. The first picture with the dry cell holder is correct though.

    It is NOT a mistake on the TQI though, don't switch any wires around.
    Last edited by RobWilJas; 07-01-2012 at 12:09 AM.
    I need R/Cers anonymous.

  6. #6
    RC poster
    Join Date
    Jul 2011
    Posts
    10
    I'm using a RX pack with my TQI and i didnt swap any wires around and it works fine...

  7. #7
    RC Turnbuckle Jr.
    Join Date
    Dec 2006
    Posts
    4,398
    OK, so I was wrong, but, this design is still wrong to me, why on earth you should go against the basic RC standard in the world?
    200, 202, 420, humor 404, 301 to rc10talk, 410.

  8. #8
    RC Champion
    Join Date
    Jul 2007
    Posts
    1,256
    To prevent someone who doesn't know any better from using the charger with AA batteries. This was a smart design IMO.
    I need R/Cers anonymous.

  9. #9
    RC Turnbuckle Jr.
    Join Date
    Dec 2006
    Posts
    4,398
    So, if I lost the battery holder and I want to use a battery holder from another truck (from a T-Maxx), I wil be able to charge the AA with a charger... So I guess this battery holder has a new part number?
    200, 202, 420, humor 404, 301 to rc10talk, 410.

  10. #10
    RC Champion
    Join Date
    Jul 2007
    Posts
    1,256
    Yes you could use a normal dry cell holder, like from the T-Maxx and you could then charge the AA's with the charge port.

    If you notice the connector on the TQi's dry cell holder is yellow instead of red, as with normal ones. Obviously it should only be used with the TQi.
    I need R/Cers anonymous.

  11. #11
    RC Turnbuckle Jr.
    Join Date
    Dec 2006
    Posts
    4,398
    Well, I could be wrong one time... .. But, you know why this happens? Because there's absolutely no information about this feature, about the sensors, how to mount them, not even a single instruction sheet, nothing, they are getting sloppy... If you want to install the sensors, you're on your own... Parts used to come with some instruction sheet before...

    Last edited by danielhr77; 07-01-2012 at 01:26 AM.
    200, 202, 420, humor 404, 301 to rc10talk, 410.

  12. #12
    RC Champion
    Join Date
    Jul 2007
    Posts
    1,256
    Yeah I agree, they need to document it or there's going to be a lot of confusion. Also you're right they need to have some directions for the telemetry stuff, as a lot of people aren't going to know how to install it. Another thing that really bugs me is there's no mention anywhere that the speed reading from the RPM sensor will not work right with a Nitro model. There's going to be a lot of people upset about that one.


    Edit: In case anyone reads this and is wondering what I'm talking about with the speed not being accurate on a nitro. The traxxas app calculates your speed from the RPM reported from the sensor. On a nitro the RPM sensor is reading the RPM of the flywheel, which is still spinning as the engine is running even when the vehicle is stopped. So, the app is always going to be reporting a speed even with the vehicle is stopped as long as the engine is running. It also doesn't account for clutch slippage when giving it very little throttle. Then if you have a 2 speed it's even worse. It will only calculate your speed correctly while in 2nd gear, so any speed readings while the vehicle is in first gear are going to be way off.
    Last edited by RobWilJas; 07-01-2012 at 01:41 AM.
    I need R/Cers anonymous.

  13. #13
    RC Turnbuckle Jr.
    Join Date
    Dec 2006
    Posts
    4,398
    Yes, I agree, I discussed that nitro issue on my forum... But, if I'm not wrong, it's the same for electric trucks, the XO-1 doesn't have a slipper, so, speed is accurate, on any other truck, isn't because the slipper will slip... And what about a 2 speed electric truck? Same thing... I guess, we will have to wait until year 201X when they will release the expansion module and the GPS module to have an accurate speed measure...
    Last edited by danielhr77; 07-01-2012 at 02:09 AM.
    200, 202, 420, humor 404, 301 to rc10talk, 410.

  14. #14
    RC Racer
    Join Date
    Aug 2008
    Location
    Sherwood Forest, UK
    Posts
    210
    Thanks for the replies guys. I guess that makes sense now.

    It's a little bit odd though that there's no mention of it in the user manual.

  15. #15
    RC Champion
    Join Date
    Jul 2007
    Posts
    1,256
    Quote Originally Posted by danielhr77 View Post
    Yes, I agree, I discussed that nitro issue on my forum... But, if I'm not wrong, it's the same for electric trucks, the XO-1 doesn't have a slipper, so, speed is accurate, on any other truck, isn't because the slipper will slip... And what about a 2 speed electric truck? Same thing... I guess, we will have to wait until year 201X when they will release the expansion module and the GPS module to have an accurate speed measure...
    Well if it's adjusted properly the slipper is only going to slip for the first foot or so that the vehicle moves, so that's really not an issue. I hadn't thought about the 2 speed electrics though. I haven't looked at one to see where the RPM sensor is getting its reading from. It depends on where it's reading RPM on whether it will be accurate in both gears or not. I'll have to look at one.

    Edit: Yeah it's reading the RPM of the Spur so it'll only be accurate in one gear.
    Last edited by RobWilJas; 07-02-2012 at 01:42 AM.
    I need R/Cers anonymous.

  16. #16
    Marshal ksb51rl's Avatar
    Join Date
    Nov 2006
    Location
    Northern NJ
    Posts
    15,878
    Quote Originally Posted by RobWilJas View Post
    ...Edit: Yeah it's reading the RPM of the Spur so it'll only be accurate in one gear...
    Wouldn't there be a direct conversion from one gear to the other? Yes, this is a bit of a hassle, but the only way I see this working for a 2-speed is mount the sensor and magnet at a wheel. That is a cumbersome thing to do with this scale vehicle and certainly puts the whole setup more at risk for damage and/or loss.

    Perhaps if there are other suggestions or issues, RobWilJas & danielhr77, they can be addressed in separate thread? The two matters above should have their own threads so neither gets "lost." Thanks for the constructive criticism.
    Alt-248 on the number pad =

  17. #17
    Traxxas Employee Nitro Chicken's Avatar
    Join Date
    Jan 2001
    Location
    Chicken coop
    Posts
    6,192
    Quote Originally Posted by RobWilJas View Post
    My guess is they did this on purpose as a safety design, and the radio will work with the negative wire in either position. With this design, the external charge jack would be wired to only charge a battery that has it`s negative wire in the proper position, like on the RX pack. By making the dry cell AA holder have the negative wire in the signal wire position, it prevents someone from using the charger port with AA batteries.

    I haven't taken mine apart to look yet but this makes sense, and if I were to design it that's exactly what I would do.
    Wow!!! You are one smart cookie! This is exactly correct. It is a safety feature that prevents people from charging AA batteries in the TQi which can cause them to explode. It is not a mistake and you should NOT modify the TQi pack.

    It does look like the picture is wrong for the RX pack just as you stated.
    Last edited by Nitro Chicken; 07-02-2012 at 11:08 AM.
    "Fortunately son, I says fortunately I keep my feathers numbered for just such an emergency!"
    Foghorn Leghorn

  18. #18
    Traxxas Employee Nitro Chicken's Avatar
    Join Date
    Jan 2001
    Location
    Chicken coop
    Posts
    6,192
    Quote Originally Posted by RobWilJas View Post
    Well if it's adjusted properly the slipper is only going to slip for the first foot or so that the vehicle moves, so that's really not an issue. I hadn't thought about the 2 speed electrics though. I haven't looked at one to see where the RPM sensor is getting its reading from. It depends on where it's reading RPM on whether it will be accurate in both gears or not. I'll have to look at one.

    Edit: Yeah it's reading the RPM of the Spur so it'll only be accurate in one gear.
    That is unfortunately true. GPS or a sensor in any output yoke or even in the tranny would be required for 2 speed nitro (Or any vehicle with a centrifugal shift hub). If it has a manual shift the APP should be able to read that and take it into account.
    "Fortunately son, I says fortunately I keep my feathers numbered for just such an emergency!"
    Foghorn Leghorn

  19. #19
    RC Turnbuckle Jr.
    Join Date
    Dec 2006
    Posts
    4,398
    Just a little piece of advice, if you start playing with the basic RC standards, please, put a sticker on the battery holder or around the wires saying that's only intended to be used on a TQi... If some who doesn't know any better uses that battery holder on a nitro truck, they will damage their receiver... A yellow plug does not say much about this feature as I've seen black, white, brown and red plugs...
    200, 202, 420, humor 404, 301 to rc10talk, 410.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •