Someone please check my math

[Thalan the Exiled]

Ok so i want to make a string blade. I plan on using about 100 led. Forward voltage is 2.8v at 20 ma. Power supply is a 3.7v battery pack. No if I use 100 I would figure the resistor like a single led using 2000ma correct? So using the nice resistor calc online I get a .45ohm 1watt resistor. Is this correct or am I doing something wrong?

[Silver Serpent]

Wattage is off. P = R * I^2. So your wattage would be 0.45ohm * 2A * 2A = 1.8watts.

There are some other concerns with long chains of LEDs in a string blade, but I'm not too familiar with them. Something about having hot spots or being brighter at one end than the other. I know people usually break the chain up into manageable segments instead of one long chain.