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Futaba T8J - Battery Life

Discussion in 'General Discussion' started by DeweyAXD, Aug 29, 2013.

  1. DeweyAXD

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    So I had my first flight experiance with my new T8J (you can see what I said about it in this thread - viewtopic.php?f=4&t=2232).

    What concerned me a bit was the battery life. The pack that came with it is this:
    [​IMG]

    Now I got 2 flights out of this from fully charged. Maximum 25 mins turned on. This was with the back light very low and the Jog shuttle LED set to off.

    So the question - What are other T8J's batt life like?

    I'm assuming this is probably just a crappy pack that needs upgrading/replacing? I know I can power my Fatshark Predator goggles through the TX batt so I can only assume there is an upgrade that will give more 'oomph'?
     
  2. Nwales

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    Like you I will be using fat shark goggles , so I'm interested in more power too .if you find anything let me know :D
     
  3. Gizmo3000

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    Something wrong going on there..

    I use 4 regular rechargeable AA's (Tennergy's , that claim about 2400mah ), and I get well over 10 hours and dozens of flights per charge.

    even in the pic, your battery claims 14-16 hours on the label, so not sure what's going on.
    the T8j also will show you battery voltage on the screen,. and it should say at least 4.8 or higher when fresh batteries are installed.
     
  4. DeweyAXD

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    Thanks Gizmo.
    Yeah I think the pack is shot so I'll see if I can get a freebie from Hobbystores.
    The manual is confusing stating: "The T8J is designed to work with either 4 AA alkaline dry cells or the HT5F1700DB pack"
    I'd love to use AA's but given that the battery bay looks like this....

    [​IMG]

    .... its not really possible?

    I get 5.4v on the charged batt but this drops to 4.8v pretty quick and then the warning goes off.
     
  5. DeweyAXD

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    Well I think found the answer in another thread by good'ol Audaciter (thank you sir if you do see this!): viewtopic.php?t=481

    I have just purchased this which seems to be what others are using and the fitment sounds good:
    http://www.hobbyking.com/hobbyking/stor ... ouse_.html

    Hopefully Hobbystore will send me a replacement for the dud pack so I have a spare too.
     
  6. Gizmo3000

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    I don't quite get it, but it seems that T8J's sold in the UK do not come with AA battery holders.
    (whereas the ones sold here in the states all come with the holder. see page 12 of the manual)
    wonder why?

    I'm sure you could contact Futaba or a dealer to find out about getting the AA adapter. (or you could probably rig one up if necessary, just use the right battery plug.

    on that note, also check page 33 of the manual
    make sure yours is set to 4 cell? (perhaps it was set to 5, which would cause the alarm to go off early!?)
     
  7. DeweyAXD

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    Weird isn't it! Unless the UK dealers remove the pack and sell them!? (I doubt that).

    I set mine to 4cell before the problem and the voltage drop is still way too fast. Interesting that it was defaulted to 5cell too so others that read this be aware of that.

    I might drop Futaba an email as you suggest. I see good things about their customer service on here (sending free de-ratchet kits etc) so you never know. I tend to always have a place in my Phantom Case for 4 spare AA batts so a holder as a backup would also be good. Hell soon I'll have enough for 3 backups!
     
  8. Gizmo3000

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    Cool.
    actually, you should have the parts to de- or re-ratchet your throttle.

    ..but they apparently do send out self-center-sprung kits for customers who inquire about it I've heard.

    good luck!
     
  9. DeweyAXD

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    Yeah not sure if I want the ratchet or not. I've sent an email to Futaba to see if they will send me the spring kit and maybe the AA battery box. I probably won't use either of them but still it'll add a bit of value when I have to sell everything to pay my credit card off :lol:

    Battery life update - I discharged the pack fully and recharged it overnight. It seems the 5 cell setting didn't save for some reason (no doubt it was user error - either that or you have to change the settings, unplug and re-plug the pack).
    I've had it on with timers running for 4hrs + now and voltage drop seems to be much slower (4.7v at the moment with no warnings).
    I'll still use the LifePo when it arrives as I'm sure it will be best for powering the goggles but at least I can fly this weekend without worrying!