Overdriving a resistored light with another cell

[Rebus]

If I overdrive a light that is
probably resistored back (it uses 4 cells)
by using 5 cells what will the effect be
on the circut and led (overheat resistor)?
How much voltage will get to the led?

I have a light that I don't care that much
about reducing led life, I just want to make
an area light that is brighter.

-Rebus

 

[star882]

If you think LEDs are sensitive, look at my "overclocking a red laser pointer" thread in the LEDs, electrolumescent, and lasers category.

 

[Steelwolf]

Should be alright.

I was calculating the voltages based on ratios and if the light you're talking about is typical, then you'd be expecting the following.

Total source voltage:
(4 cells) 6V
(5 cells) 7.5V

Voltage across LEDs:
(4 cells) 4V
(5 cells) 5V

Voltage across resistor:
(4 cells) 2V
(5 cells) 2.5V

The last part is to look at the Nichia LED specs to see the current expected at those voltages and multiply that by the number of LEDs in the array. This will tell you how much current will be drawn and therefore how much current passes through the resistor.

Knowing that resistors come typically as 1/8W, 1/4W, 1/2W, 1W and so on, you can get an idea if the increase is still within the resistor's capacity.

Good luck.

 

[sunspot]

You might try to lower the resistor value that is already in your light. That way you get a brighter light without adding a battery.