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  1. #1
    mtbr member
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    Light Trauma- New L&M battery or new 3 x cree homebuild

    Having a bit of a trauma and I thought I'd ask the mtbr massiff's thoughts

    My brother has a L&M HID that the NiMH battery appears to be on its way out, he's getting less than an hour of light which is next to useless

    Problem is that the L&M 10.8 volt NiMH batteries are 90 quid.

    We went out for a ride on the Marin on Friday night and it was the first time I'd had chance to see how my 3 x CREE led cutter kit build faired up against a HID. TBH it was just as good.

    I reckon I could build a light up from scratch for pretty close to the cost of the battery alone

    30.00 Lumicycle Can inc bracket (http://www.lumicycle.com/Product/pro...ALO_UNIT&dep=5) (25 for Cateye ABS housing)
    45.00 for the cutter kit (maxflex)
    12.95 for a 7.2 volt 3700mAH battery (http://component-shop.co.uk/html/large_packs.html)
    13.50 for a 500mA/1000mA charger (http://component-shop.co.uk/html/radio_control1.html)
    10.00 for glue, heat compound, bits of wire, connectors and shrink wrap

    ---------

    101.45 Total

    What I haven't seen cheaply is the ideal 14.8volt NiMH + charger to suit a bflex

    The other option would be to get a 10.8 volt battery built (9 cells) but I cant find a charger that would charge 9 cells. The L&M battery has a completely non standard connector and temp sensed charging.

    Question I have is if the battery is dying, how much life is the HID bulb likely to have.

    Any thoughts?

    Ian

  2. #2
    mtbr member
    Reputation: heatstroke's Avatar
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    Jul 2003
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    I suggest you buy a couple of NIMH battery packs and rebuild your L&M NIMH battery pack - Temp electronics and all.
    Or you can try ebay for a 10.8V battery pack, get you own connectors and spend 25 quid on a smart charter. (or batteryspace has the nimh charger for about 23USD)

    The problem with the lumicycle can is that you still need a decent heatsink behind the led and good thermal path to the can. just a bit of artic silver aint going to do it.

    The maxflex/fatman should be thermally connected to the casing if you're running close to 1A. CPF has info on this. I think the Bfex option is preferable.

  3. #3
    Singletrack Daydreamer
    Reputation: rockymtnway's Avatar
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    Nov 2004
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    346
    Agreed that the jury is still out on some of these triple cree homebrew can lights, as to whether the questionable heatsinking will burn them up with time. If you can, it might be cheaper to go the Achesalot homebrew design and you'll have a much better chance at getting the cooling you need.

    Unless you can get a really solid and reliable conduit to get your heat from the back of the LEDs to the housing, you're likely to cook your LEDs and electronics in the next year or two. Otherwise, I'm all in favor of binning the L&M and moving toward the LEDs. Heck, you could recover a fair bit or your costs by selling the L&M. If you go with the Achesalot design, you can go with a cheaper BuckPuck (dimmable preferred), too, if you get a 13.7v-14.4v Nicad/NiMH. Overall, the project would likely come in around 90-120 quid, given typical overruns (your current estimate seems pretty low, given the start up costs for your first project (wires, switches, solder, shrinkwrap, Arctic Silver must all be purchased if not already on hand and each item might cost 2-10 quid)).
    Train 'til you puke. Cheat to win. Party like a rockstar. We miss you, Jan!

  4. #4
    Do It Yourself
    Reputation: Homebrew's Avatar
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    Jan 2004
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    I'm not sure about a UK source for cells, but I'm sure you can rebuild the pack for much less that 90 quid. The cells are 4/3A cells and the thermister is just taped to the side of the pack (i.e. easy to affix with a new piece of tape). And even if you don't want to rebuild the pack in the same configuration, you can always reuse the connector cord. It's not to hard to figure out which wire goes where.

    I agree with the others and don't think the Lumicycle can and Cutter kit alone are a good solution. That really doesn't properly heat sink the lights. Just my 2 cents (actual value declining by the day).

    Additionally, if your bro decides to sell the Arc as is, let me know.
    Long Live Long Rides

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