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  1. #1
    chips & bier
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    Fixing my triple shot (electronics for dummies)

    So, I now regret sleeping through the 1 electronics course we had in college...

    Last weekend my CatEye's battery drew its last breath, so I need to fix it pretty fast. Will probably solder a brighter LED in the center as well, but my main issue for the moment is the battery.

    I've taken the original CatEye battery (controller + 10 AA's) apart, and from I what I can see I could get away with ordering a set of 10 of these, reconnecting the mess, and I'll be in business. I'd be short 0.2 Ah in terms of battery life, but that's better than 10 min. of use.

    Are there any other (better) solutions I should look at? I know a couple of people are using camcorder batteries and the like....

    Thanks!

  2. #2
    Homer
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    10 x 3,7 x 2,5 = 92,5WH
    That's 3 times the capacity you have now.
    Those Trustfires are Li-ion in a 18650 package, significantly bigger than AA (14600).
    Apart from the danger or 'challenges' that come with constructing your own Li-ion battery I would't know what the 'Triple will eat in terms of input voltage.
    I'd say NiMH would be the way to go, or a complete/ pre-built Li-ion pack w. compatible charger.

    Can you post some pics of the original battery?
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  3. #3
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    I agree with Brum. It sounds dangerous to me. Stick with NiMH.

  4. #4
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    If the Cateye already uses AA cell's, I would just go out to the store and buy some good AA's and put those in. There is no protection circuitry on those Lion batteries, I'd be a little nervous.
    I build packs out of store bought AA all the time and you can get them up to 2800mah now.
    2650's for Duracell off the store shelf last week, 4 pack was $14. No worries about overcharging issues, like a house fire.

    Eric S

  5. #5
    chips & bier
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    Here's a battery pic.

    I realise Li-ion cells are pretty intolerant of over(dis)charge, but things are still on the drawing board for the moment.

    The local DIY electronics shop sells NiMH AA's like the original unit is made of, but as I said: I'd like something lighter if possible.
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  6. #6
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    Can you post the photo from the second side - to see how cells are connected ?
    Or simply, are they all in series to get 12V ?

    If that so - you can use Li-ion 11,1V protected battery pack without any hesitation - the voltage range for 10 NiMH's is 11-14,5v for 3xLi-Ion(3,7) = 10-12,6. You should also check if it can handle 14,4V Li-ion pack (max 16,8V) if yes, then you should choose 14,4V battery pack or replace driver in this small plastic box on the cable for bFlex i.e.

  7. #7
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    Yup, all connected in series. Those are some interesting ideas. I do want to be able to use my light for racing as well, plus I carry my battery in my backpack. These are the main reasons I'm being a weenie about the NiMH weight. If I can find a decent solution paying significantly more for good Li-ion packs isn't an issue for me. Thanks!!!

  8. #8
    Do It Yourself
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    Quote Originally Posted by eric
    Are there any other (better) solutions I should look at? I know a couple of people are using camcorder batteries and the like....

    Thanks!
    It depends on how good of a solution you're looking for. You definitely don't want 10 x 18650 though unless you're wanting to build multiple packs. Also, I wouldn't use those protected 18650 cells unless you're using it a single cell flashlight. For battery packs, you need to wire the cells together and you can't solder them directly. You want tabbed cells like these:

    http://cgi.ebay.com/Four-18650-Li-Io...QQcmdZViewItem

    And I wouldn't buy loose cells unless you get a really good circuit protection. If you want a really good controller board, the bFlex from TaskLED. It has multiple light levels, and excellent circuit protection (low voltage warning, temperature controls, short, reverse polarity, etc). With this controller, you can use raw Li-Ion cells. However, with a less robust controller, you'll need another protection circuit so I would recommend getting a pack already built with protection like this one:

    http://cgi.ebay.com/Lithium-Li-Ion-1...QQcmdZViewItem

    I would highly recommend upgrading the LEDs to U-Bin SSC. I did my Double Shot and it's so much better. You should be able to get near HID brightness out of the Triple Shot.
    Long Live Long Rides

  9. #9
    Homer
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    Quote Originally Posted by Homebrew
    It depends on how good of a solution you're looking for. You definitely don't want 10 x 18650 though unless you're wanting to build multiple packs. Also, I wouldn't use those protected 18650 cells unless you're using it a single cell flashlight. For battery packs, you need to wire the cells together and you can't solder them directly. You want tabbed cells like these:

    http://cgi.ebay.com/Four-18650-Li-Io...QQcmdZViewItem

    And I wouldn't buy loose cells unless you get a really good circuit protection. If you want a really good controller board, the bFlex from TaskLED. It has multiple light levels, and excellent circuit protection (low voltage warning, temperature controls, short, reverse polarity, etc). With this controller, you can use raw Li-Ion cells. However, with a less robust controller, you'll need another protection circuit so I would recommend getting a pack already built with protection like this one:

    http://cgi.ebay.com/Lithium-Li-Ion-1...QQcmdZViewItem

    I would highly recommend upgrading the LEDs to U-Bin SSC. I did my Double Shot and it's so much better. You should be able to get near HID brightness out of the Triple Shot.
    The bFlex might protect the total pack from overdischarge, but thats no good.

    You need protection for each cell, and temperature protection for the entire pack. bFlex can't provide either, perfect driver nonetheless but it has nothing to do with Li-ion pack protection systems.
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  10. #10
    Dr Gadget is IN
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    Here are some examples of the circuit protectors which are HIGHLY RECOMMENDED to prevent "ejection of burning debris" from your battery. One DIY'er I read stated that a simple touching together of battery leads on his bench lead to a smoking hole - overdischarge just wastes money. Overcharge or excessive load lead to excessive excitement as well as loss of battery, hand, house, etc.....

    http://www.all-battery.com/index.asp...S&Category=178

    The issue with changing out a cateye battery while keeping the same controller would be max voltage. IIRC the buckpuck will take 32V max.
    I'm running these: http://www.all-battery.com/index.asp...OD&ProdID=1578 $60
    driving a 1A buckpuck,
    http://www.ledsupply.com/buckpuck.php $15 + harness $5
    and a simple charger: http://www.all-battery.com/index.asp...ROD&ProdID=478 $23

    Oh, and SSC P4's in the housing:
    http://www.dealextreme.com/search.dx/search.seoul%20p4 $6/ea

    By the time you go to the trouble to get one emitter out - might as well replace all of them. That's the cheap part.
    This isn't a "you're doing it wrong" topic.

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  11. #11
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    You can get li-ion protection circuits from batteryspace:
    http://www.batteryspace.com/index.as...S&Category=711

    I've built several batteries using li-ion notebook battery cells using these circuit boards.

    As far as getting the light working, just use ni-mh cells, and then consider getting another light. By the time you get li-ion cells, protection circuit, a charger, a controller, and a new led, what have you got left of the original light?

  12. #12
    Homer
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    The USA-based battery companies are no good for us europeans, they either don't ship overseas or they charge ridiculous carriage fees.

    The Li-ion protecion PCB's can be also be had through Ebay.
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  13. #13
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    Quote Originally Posted by brum
    The bFlex might protect the total pack from overdischarge, but thats no good.

    You need protection for each cell, and temperature protection for the entire pack. bFlex can't provide either, perfect driver nonetheless but it has nothing to do with Li-ion pack protection systems.

    You're right, getting a pack with protection built in is the only way to go. It eliminates the issue with the protection and the soldering tabs. Although, I don't really think some of the "protection" circuits are worth a flip as they could allow the cells to go all the way down to 2.3V. I'd like the see it stop closer to 3V even. Check the specs before you buy.
    Long Live Long Rides

  14. #14
    Dr Gadget is IN
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    Quote Originally Posted by qdave
    By the time you get li-ion cells, protection circuit, a charger, a controller, and a new led, what have you got left of the original light?
    Well, you've got a very nice housing with a good mounting system - which you can upgrade with better emitters as available.
    This isn't a "you're doing it wrong" topic.

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