It's on the datasheet. Then you need to do some simple arithmatic.
A fan would also help cool it.
I am thinking of using two 150 1/2W resistors in parallel. It would mean that they would need to dissipate about .81W total (.4W or so each) which is under .5W. Would this work, or am I stressing the resistors too much in doing so, or am I limiting the voltage too much?
Your supply is 10.3V
The LEDs are probably 2V.
The LM3914 is set for 10.4mA at its outputs.
With 104mA, a resistance of 75 ohms dissipates 0.81W as you say. But then only 2.5V is available to the LM3914 outputs which isn't enough for them to regulate the current properly? (It is probably pretty close. I didn't calculate it) :lol: :lol: