Flat top 18650 flash lights

TxWelder35

WELDERAT0R
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Minuteman
  • Oct 17, 2018
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    Looking for flashlights and IR lights that will accept a flat top 18650 battery. I know a lot of flashlights can take the regular 18650s but these batteries are 1/4” shorter than those. Wanted to see if there was any flashlights out there that will work with these. I have a bunch of em so I would like to buy some more stuff to make use of them.
    C95B7CDF-3A5C-4721-97BB-54CBC1ADBA55.jpeg
     
    The difference in length, in addition to the button top, is the lack of a protection circuit.
    The INR cell is in the middle of safe type cells. IMR, INR, ICR.
    IF your application is a "safe" device you could use a spacer or current limiter (shown at top of photo).
    View attachment 8538115
    What exactly is a “safe” device? My thermal is what uses these and got a bunch of em for it. What does the circuit protection actually do?
     
    The circuit protection circuit board at the neg end of the cell and a connection to the pos end has an overcurrent/short circuit cutoff, an over discharge limit, an over charge limit.
    If your device has these built in protections then a protected (longer) cell might not be needed.

    The protection boards are designed for low, med, high current drawing devices.
    Each Mosfet switch on the board will have a continuous rating of "about" 2, 4, or 6 amps.
    Short term maybe a little higher. HIGH current like drill motors, saws use unprotected cells in packs with built in protection.
    ProtectionBoards.jpg

    3mosfet-board.jpg


    I could say "IF your device has this or that safety features" then you could use unprotected cells and not worry.
    But I won't. Consult the manufacturer for cell recommendations.
    SOMETIMES long battery compartments are INTENDED for longer cells with protection.
     
    Last edited:
    This might help with a hint as to what the manufacturer intended for protected vs unprotected.
    If a protected cell is too long,
    If the positive contact is flat, button top required.
    Tail switched flashlight needs insulation without nicks or tears.
    If the device has a raised positive post a flattop is indicated.
    P1110703.jpg

    P1110696.jpg


    If a stack of 18650 cells is needed, button top. Might take long (Protected) or shorter (Unprotected).