I'm starting to plan out a Saber build and doing what research I can but I've got a question related to rounding up on resistors.
First, I'll give the math to see if it looks correct to everyone. This build will have a 3.7v 18650 cell powering a Cree Tri XP E2 Red/Red/White. I will be using a NBv3, so the LED's must be wired in parallel.
The red LED's are 2.59v @1000mA, and the white is 3.15v @1000mA. My math works out at 1.1 ohms/1.1W for the red and 0.55 ohms/0.55W for the white.
For the white LED it's an easy choice to round up to a 1ohm/2W resistor. For the red, the first round up choice is a 1.2ohm resistor. However, since a fully charged Li-ion battery can actually provide 4v, should I be rounding up to the 1.5ohm resistor to be safe?
As a bonus question, one of the tutorials on this site recommends that when wiring in parallel, each LED should have its own resistor. But the wiring diagram in the NBv3 manual recommends a resistor for the white, and a single resistor for the two reds, splitting the wiring after the resistor to wire them in parallel. Does it matter much? Space is likely at a premium here.
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