Ultrasound 2.5 LED Wiring Question

[ForeverAJedi]

I have a saber that I built a few years ago running a blue Luxeon K2, an Ultrasound 2.5, and a 4AA battery pack. I would like to convert this saber to a rechargeable saber using this battery pack:

http://www.thecustomsabershop.com/74v-Li-ion-1050mAh-14650-Battery-Pack-P759.aspx

When doing a little digging on the Ultrasound 2.5, I found that the max voltage for the board is 9.6V and for a K2 LED the max voltage is 7.2V, according to the manual for the board (http://www.fx-sabers.com/forum/index.php?topic=19915.0), though 6V is recommended.

My question is: should I run a resistor between the LED and the soundboard to bring the voltage down to 7.2V from the 7.4V coming from the battery (is that even needed?) or should I bring down the voltage to the 6V?

[Kouri]

Lithium-ions are alternately rated 3.6-3.7v, so serial packs wind up with a rating of 7.2-7.4v, so I wouldn't worry too much about a resistor to drop 0.2v.

Beyond that~ I don't really know. I don't have any technical specs on the board to go off of - you'd need to do some old digging comparing old LED specs to current offerings and see what fits best.

[ForeverAJedi]

Thank you Kouri. Taken from the online manual found here: http://www.fx-sabers.com/forum/index.php?topic=19915.0

Installation specifications and requirements.

LED choices:
1. Luxeon 3 all colors white/blue/green (1000mah)
2. Luxeon 3 red/amber/red-orange (1400mah)
3. Luxeon 5 (850mah)
4. Luxeon K2 (1500mah)
5. Luxeon 3 Overdrive (1200mah)
IMPORTANT! (be sure to select the correct LED type installed in your saber)

Battery input voltage:
Maximum for board = 9.6V
Minimum/Maximum for Luxeon 3, K2, P4 = 4.5V / 7.2V (6V recommended)
Minimum/Maximum for Luxeon 3,P4 Red/Amber = 4.8V / 6.0V
Minimum for Luxeon 5 = 7.2V
IMPORTANT! (be sure to use the correct voltage/power with corresponding LED type)

I think I'll be OK, but I wanted to post here to make sure.