Help with LED light... turns off after battery voltage drops

Discussion in 'The Projects Forum' started by VOMITRON, Jul 10, 2011.

  1. VOMITRON

    Thread Starter New Member

    Jul 10, 2011
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    I have an LED mining lamp... can be seen here: [​IMG]

    The problem I have is after about 6 hours it just shuts off. This is obviously due to low battery voltage because if you let it sit there and dry charge itself, it will run a little while again, then shut off once more. I don't know a whole lot about electronics but since I have other LED flashlights that will run all the way until the light dims to nothing, then this light must have something in it that is shutting it down... any idea's? I would just like to force this thing to run until it fizzles out instead of it just shutting off on me.

    Edit: it is li-ion powered so I don't know if that is significant in any way
     
    Last edited: Jul 10, 2011
  2. SgtWookie

    Expert

    Jul 17, 2007
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    Certain types of rechargeable batteries will become damaged if they are discharged too deeply. The engineers probably designed the circuit so that it would turn off before the batteries were at risk.

    If you managed to disable that feature, your light operating time would not increase very much, but you would risk killing your batteries.
     
  3. #12

    Expert

    Nov 30, 2010
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    In addition to that, nobody can be sure what the answer is without a schematic. So, take it from wookie or post a drawing and probably still get the same answer, "don't do it".
     
  4. iONic

    AAC Fanatic!

    Nov 16, 2007
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    Do you think a switch to 50% power after the first fail might allow a bit more light and still not run into the damage the battery scenario? Either way the batteries have about had it and the best solution would be to have a spare set with you and to practice changing them in the dark!
     
  5. SgtWookie

    Expert

    Jul 17, 2007
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    I missed that it has Li-Ion batteries.

    One of the worst things you can do to a Li-ion battery is to run it out completely all the time. Full discharges put a lot of strain on the battery, and it's much better practice to do shallow discharges to no lower than 20 percent. In a way, this is like people running for exercise— running a few miles a day is fine, but running a marathon every day is generally not sustainable. If your Li-ion powered device is running out of juice on a daily basis, you're decreasing its overall useful lifespan, and should probably work some charging stations into your day or change your devices' settings so that it's not churning through its battery so quickly.

    Also, read up here:
    http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries
    Look in particular at Table 2; cycle life vs depth of discharge.
     
  6. KJ6EAD

    Senior Member

    Apr 30, 2011
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  7. iONic

    AAC Fanatic!

    Nov 16, 2007
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    I'll second the Princton Tec products. I've used the APEX and love it, but it really depends on your intended use.
     
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