So I can't seem to find an obvious answer, but i'm pretty certain the answer is indeed obvious. I searched online for an answer but the keywords tend to supply me with other information that doesn't quite answer my question.

My question is about making a basic circuit with batteries and 2 leds.

The LED Vf is 3 volts, and operates at 20mA

Im using 2 LED (6 Vf)

I have a battery pack of 4 Double A Batteries: 1.5 X 4 = 6V

Obviously when i go to calculate the ohms of resistance i'm going to get 0 because they cancel each other out.

I suspect that IF this were to run, the battery life would run much less efficient but -

Otherwise,do I calculate the resistance needed from the 6V battery alone in which case I use a 300ohb resistor? Or is the voltage portion of the calculation V = 6v-6v

My ultimate quesiton is - Will this burn out the LEDs immediately if I dont use any resistor? OR are there any obvious problems I'm going to run into. I'm a very noobish noob, and I'm not sure if this is even worth wiring up or if It's impossible. If it is impossible, I will 3d print a new battery tray to hold 5 batteries, but this will be larger than my design was intended to be. So if possible, i'd want the 4 batteries to work.

My question is about making a basic circuit with batteries and 2 leds.

The LED Vf is 3 volts, and operates at 20mA

Im using 2 LED (6 Vf)

I have a battery pack of 4 Double A Batteries: 1.5 X 4 = 6V

Obviously when i go to calculate the ohms of resistance i'm going to get 0 because they cancel each other out.

I suspect that IF this were to run, the battery life would run much less efficient but -

Otherwise,do I calculate the resistance needed from the 6V battery alone in which case I use a 300ohb resistor? Or is the voltage portion of the calculation V = 6v-6v

My ultimate quesiton is - Will this burn out the LEDs immediately if I dont use any resistor? OR are there any obvious problems I'm going to run into. I'm a very noobish noob, and I'm not sure if this is even worth wiring up or if It's impossible. If it is impossible, I will 3d print a new battery tray to hold 5 batteries, but this will be larger than my design was intended to be. So if possible, i'd want the 4 batteries to work.

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