nanobiscotte resistor question

[Silver Serpent]

If you have room for it, the 18650 will give you longer runtimes. Both will give you the same brightness.

[psab keel]

Does the Drive parameter yield a consistent current like a typical driver would, or will it fluctuate? In other words, if the LED is set to 1000 mA with the drive parameter, then the current can never exceed feeding 1000 mA to the LED? I guess my questions relate more to how efficient this setting is, vs having a resistor or even a micro puck driver in the design in terms of regulating the LED current.

[Darth Scorn]

I know a p4 red can be ran at 3v max it says in the shop, but would I be asking to much to not have to put in a resistor and run it on the 3.7v?

[Forgetful Jedi Knight]

I know a p4 red can be ran at 3v max it says in the shop, but would I be asking to much to not have to put in a resistor and run it on the 3.7v?

Yes, you would be asking too much... WAY too much. Put a resistor on it, just to be safe. The specs as I remember them had the lower end of the Vf at around 3.1 - 3.2.

[Darth Scorn]

cool thanks better be safe than have a fried led

[whitmers]

my next plan is to rewire the speaker holder to run two 14,500s in parallel so that I can consistently use the same type of power cells as my other sabers. While I am going inside the saber again, has anyone use the nano biscotte's led slot for illuminating a crystal chamber yet?

[jedimastergarcia87]

I'm wondering if a resistor is needed if you do a P4 green and a single 18650. I saw the new pre-wired Nano Biscotte so I may give it a whirl.

[Silver Serpent]

You can get by without a resistor with that setup JMG.

[Captain]

Could I do without a resistor with a white rebel star LED? And if I do not use a resistor will I have to change the Drive parameters?

[Silver Serpent]

If the voltage of your battery pack is equal to, or slightly less than, the forward voltage of your LED, then you will not need a resistor.

With a single li-ion, your battery voltage is 3.7 (up to 4.2 when fully charged). White Rebel has a Vf of 3.1v, so you'll need a resistor. The Seoul P4 green has a Vf of 4.1v, so a resistor is not necessary.

Changing the drive parameter is good for fine tuning, but a resistor is the better way to adjust if you have a significant difference in power between your LED and battery pack.