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  1. #1
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    Battery help for iBlaast

    I need some electrical help here. I have just ordered an iBlaast. I am planning on using 2 sets of batteries that I currently have. They are 7.2v 4800mAh. Batteryspace told me I could run those in a series but I would need to "figure out what is the initial current load of your light by calculation below.

    (Wattage of light x 3) / 12V

    If the initial current drian was greater than 10A, you may change the PCB to 9A for each 7.4V 4800 module for the 18A Max discharge current 14.8V 4800 mAh pack." It looks like the iBlaast is runs 3 4 watt LEDs for a total of 12 watts. Do I need to order another PCB or will the one that came with it be fine. It is an older battery but here is a link to the one listed currently on their site http://www.batteryspace.com/index.as...OD&ProdID=2950. I am a electrical nube so please help.

  2. #2
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    I'm pretty sure the iBlast uses a bflex 'buck' driver to drop the voltage down to the required level

    OK then I'll try and explain something I've only recently learnt

    The 3 led's in your light will draw about 3.5 volts each. The different levels of light produced by the iBlast is done by changing the current. max is typically 1000mA (or 1 amp)

    So the led's will be drawing approx 10.5 volts at 1 amp = 10.5 x 1 = 10.5 watts

    The batteries wired in series need to produce the same wattage at 14.4 volts = 10.5 / 14.4 = 0.727 amps or 729mA

    So basically you'll have 0.7 of an amp coming out of each 7.2volt battery to drive the light

    You won't have a problem with the battery protection circuits as they are from what I can see

    I hope this helps

    ian

  3. #3
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    Thanks Ian.

  4. #4
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    The battery in your link has a 7-amp polyswitch protecting it for overdischarge. The iBlast should only draw ~ 1 amp max, more like 750 mA, so no problem.
    In series, the battery voltage is the sum of the two or 14.4V. The mAh is still 4800, so about 4.8 hrs. at the max light.

  5. #5
    my dog's Frisbee launcher
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    Rob...I will start a new Thread this might derail your Question.
    Last edited by befoot; 12-17-2007 at 11:26 AM.
    Darwin was an Optimist

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