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SKYWLKR said:
since it's regulating voltage...(there is only a certian avaiable amount of amps in a series battery setup..)
do you get more run time and/or brightness from a 4cell D vs a 2 or 3 cell?
how bout a 6 cell.
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If you look at my table, I saw 3 steps of brightness (not measured). Mine needed 3.8V to start at the highest level, but could drop to about 2.9V and maintain this visual level. Since it appears to be trying to regulate current to the Luxeon and since the Luxeon will have a fairly constant voltage drop across it, the everLED could be thought of as a constant power drain when running at these voltages (what I did in the calculation). The power formula is P (power in watts) = I (current in amperes) * V (voltage in volts). Oversimplifing it, a battery could be thought of as a device which supplys a certain amount of power for a given time: Watt / hours. Because power is current times voltage it doesn't matter if you have the same number of cells in series or in parallel, the watt/hours are the same. With the everLED if the voltage is above 3.8V the power drain rate is nearly constant, so that runtime is increased nearly proportional to the number of cells added. Six cells should run about twice as long as three. In the real world batteries are not perfect and the everLED does vary in its power usage. And dropping out of the higher regulated state things get more complicated than I care to think about. When running two cells you will be drawing less power but you also have fewer watt/hours available and producing less light. To me this is comparing oranges and grapefruit, yes they're both citrus but not the same. By now I'm sure everyone has reached the point of MEGO.