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  1. O

    4000mah?

    Can we actually buy cheap 18650's that even _approach_ 4000mAH? I recently bought some "4000 mAH" 18650 cells. They were on the fleabay price scale. When one died quite fast I did a discharge to 3V /charge to full cycle on my smart charger and found that the charge cycle stopped at 1450 mAH...
  2. O

    Bulging batteries

    Thanks for that. Boy these batteries are a bit drama queen aren't they? I have certainly not done anything to either of these. I did badly under discharge another one, though and it's fine! Shrug
  3. O

    Bulging batteries

    I have maybe 1/2 dozen LiPo batterties. Two of them have bulged. Neither of them has had hard use or charging. They have both sat for maybe 3-4 months unused innside the house at a max temp of 30-32 C. Same as the others. But they have bulged. One is a Turnigy and the other is a Chinese-bought...
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    Strip LEDs: Series or parallel

    Yeah there are many LED bulbs that are not dimmable, because the driver circuit in them is already a constant current device, and also if you try to use PWM to dim them, it will just conflict with the output pulses of the driver already in the globe. Changing the voltage should not affect a...
  5. O

    Strip LEDs: Series or parallel

    No I actually am dimming them. I was just puzzled how they kept going down to such a low voltage. However see my embassing results.
  6. O

    Strip LEDs: Series or parallel

    Yeah it is PWM. Now I do feel silly. The multimeter would read narrow pulses as low voltage. Thanks for jogging my ageing grey matter into activity:oops:
  7. O

    Strip LEDs: Series or parallel

    I assumed that the 3 LEDs per mini-section are in series. However, I was using a dimmer on one and reading the output voltage of the dimmer showed 5.2V just before extinguishment of the LEDs. I may be making a twit of myself, but how do 3 series LEDs keep going down to 5.2 volts total?Thanks for...
  8. O

    Soldering protected lipo 3.6 cells

    OK. Thanks for that. It's what I feared. I will have to find an alternative.
  9. O

    Triangular AA battery holders

    I need these holders to power my HyBoccum Earth Little Part Seeking Travel Machine:sssh:..it's a work in progress.....
  10. O

    Triangular AA battery holders

    Tried the search...no luck. South Hill, VA, is a LONG way from Perth, WA (Western Australia) :D
  11. O

    Soldering protected lipo 3.6 cells

    Does it work? Or am I at risk of damaging the protection circuits? I am not sure where they are physically on batteries, but I can see where they may be, waiting to die from soldering heat.... Thanks for any help.
  12. O

    Triangular AA battery holders

    Thanks for the replies. Tried the DAGS for 3S AA round holder and ....mmmm... $15 for the holder! That is more than the torch I bought to convert!...and the AA Lipo cells. Well about as much as both, for a bit of wire and plastic. Seems I need to look at alternatives.
  13. O

    Triangular AA battery holders

    ...like the AAA ones that many small LED torches have on.y for AA. I want to put 2 lots of 3 AA's into a torch barrel. Thanks for any help EDIT: To clear things up, I do not want the AA->D converter. I want the cells in series to drive 3 LEDs.
  14. O

    Cell count vs LED count XM-LAWT

    OK. Thanks. I will certainly take that on board. 3 of these guys at 3A will put out a LOT of light, so they will not always be at that current, but there will be times, and I also want them for permanent lighting, where coolth is paramount. Luckily there, size and weight do not matter much.
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    Cell count vs LED count XM-LAWT

    Thanks for that. I had another look and realised my question is probably not needed :o. The XMLawts have a very low FV, and a cell per LED is plenty. Sounds like a bit heavier stock or more heatsinking is in the pipeline!
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    Cell count vs LED count XM-LAWT

    WOW! None too good. I was expecting better from here.....
  17. O

    Cell count vs LED count XM-LAWT

    I am organising some Cree XM-L LEDs, and also buying lipo batteries to drive them. It _looks_ to me as if I can drive the LEDs on a one-to-one basis with the batteries, just using a buck current regulator. I want to run 3 in series, with a 3S pack. I can see an obvious safety factor there, but...
  18. O

    Poorman Mutli-Lux setup method

    Just OOI, is there _that_ much extra work to be done? As I see it (may be brain fart day) if the voltage were half (4:2), there would only be a bit extra.....unless the chips are rtight at their limit at 2.8A. At 2.8A should the chips not be heatsinked anyway?
  19. O

    10A Buck Switching Regulator

    Interesting thread indeed. It's the regulator you need to match, and let it take care of the LED (??) How about using a trimpot in parallel with the thermistor, as well as the one in series? Then you could set for as little voltage drop or as much as required (???), within reason. Use the...
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    Poorman Mutli-Lux setup method

    Hah! Well found and well fixed download. When I read the reply in my email I read only the first couple of lines, and I was going to say that maybe it was the circuit/wiring rather than the actual chip.....but there you have gone and done it. I have made little progress. I bought a new camera...
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