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Thread: Greatly improve your TM11's negative contact

  1. #1

    Default Greatly improve your TM11's negative contact

    It's been only a few hours since I got my TM11 v.1.12 from GS (Amazing deal) and I have encountered a big "Flaw", a problem perhaps never seen on flashlights before: Batteries are too short. Using my Panasonic 3100mah NCR unprotected cells, soldering tabs to the positive end wasn't enough, the battery is simply too short and wobbles inside the battery holder. Same with the 2xCR123 setup, they wobble and loose contact.

    Lifting up the thin copper plate wouldn't do the job neither, and I dont particularly trust magnets/spacer for high drain applications like this. So I broke down 4 battery holders I got from ebay and extracted the spring. Then carefully "screwed" them to each of the contacts until they would stay in place. The spring rises the battery about 2mm. There is no need for this mod if you plan to use the TM11 only with protected cells.



    Now my unprotected Panasonic and Sanyo 2600mah work perfectly in the TM11. Soon I will be using LG 4.35v 3000mah cells.


  2. #2
    Flashaholic* LitFuse's Avatar
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    Default Re: Greatly improve your TM11's negative contact

    It's hard to tell for sure from your picture, but those appear to be some small gauge springs. I think you could run into a problem where they might get "cooked" when the TM11 is run on high or turbo. High amperage and narrow gauge wire is a recipe for resistance and rapid heating.

  3. #3

    Default Re: Greatly improve your TM11's negative contact

    The springs definitively looks thinner than they are. Well I test ran these battery holders by hooking up a 3S1P setup to power a 35w HID drawing about steady 4.1 amps while using 18awg cable. The springs did just fine, the cable did got a little warm. I highly doubt these will get cooked in the TM11, since the contact surface is good and distance short between the base plate and the battery. I always ensure to run 4 cells in parallel, because I've noticed these NCR cells do not perform great under high drain.


  4. #4
    Flashaholic Pandorum's Avatar
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    Default Re: Greatly improve your TM11's negative contact

    Nice mod.
    I don't understand why Nitecore couldn't be bothered to have springs there in the first place.

  5. #5

    Default Re: Greatly improve your TM11's negative contact

    Quote Originally Posted by Pandorum View Post
    Nice mod.
    I don't understand why Nitecore couldn't be bothered to have springs there in the first place.
    Possibly greater contact area with the current arrangement? Just speculation...

  6. #6

    Default Re: Greatly improve your TM11's negative contact

    In many applications, the leaf springs used in the TM11 offer less electrical resistance than the coil springs. I personally prefer the protected cells in the TM11. You really would not want any of the cells to get reverse-charged by the other cells. Due to the way the batteries are connected, (4 parallel cells) this is something that could easily happen. You could quickly have a $260 pipe bomb with lots of thick aluminum shrapnel.

  7. #7

    Default Re: Greatly improve your TM11's negative contact

    Parallel cells would be nearly impossible to reverse charge. It's series cells you have to watch like a hawk. Should a parallel battery have a cell that drains completely, what'll end up happening is the stronger cells would just end up charging the weaker cells maintaining the same voltage.

  8. #8

    Default Re: Greatly improve your TM11's negative contact

    Point taken. All the things you learn every day!

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