What do I need?

[pudly]

I'm planning on doing a single color cree xp-e2 led MWS module and a latching led av switch. Also there will be no sound. Can someone tell me what type of battery back I will need?
Hopefully I can go as far as I can with none-to-minimal saudering and just use jst connectors.

Any help would be great.

-Pud

[BZWingZero]

For something like that, you could use 2xAA batteries and a resistor, but you wouldn't have much runtime.

Your best bet is a single 18650, which runs at 3.7v. You'll still need a resistor. Exactly which one will depend on which color LED you choose.

[pudly]

I will be getting the green cree led MWS module
EDIT:
Ok, with the Ohm's law and a calculator I'm getting this:
6v(4xAAA) -3.58 Vf Green Cree LED at 1000mA = 2.42 ohm resistance
and
2.42 ^2 = 6w

So rounding up I should use a 2.7 ohm 10w resistor...
Is that about right?

[Silver Serpent]

Your wattage calculation is incorrrect. It should be R * I^2. 2.42 * 1^2 = 2.42. A 2.7 ohm 3 watt resistor is fine. The 10 watt will work, but it's really really big.

[pudly]

oh yeah, you're right! I was thinking it was R squared, but it's not its I squared. Thank you, My bad. The only resistor the shop has is 2.7ohm 10w, unless I get it from somewhere else.

[darth_chasm]

Why not use a li-ion? In the long run you'll end up saving money. And you'll be able to use a significantly smaller resistor.

[pudly]

Do I need to take into account the led in the AV switch module if it's pre-wired with DynaOhm resistor?

[Silver Serpent]

Wire it parallel with the main blade LED, and the DynaOhm will take care of feeding your switch LED automatically.