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Single Blinking LED Battery longevity. Which is best, (2) AA or 9 volt?

Want to know what is the best method to power a single Blinking White 5mm LED and get the most battery life. How long and what type battery could keep it going continuously the longest?

Picture of Single Blinking LED Battery longevity. Which is best, (2) AA or 9 volt?
Dr.Bill7 years ago
2 AA i have made fake alarm lights doing this
110100101108 years ago
the AAs

my estimation. i dont know the real AH of batteries (and its different with every manufacturer). i estimate based on experience and the volume of the AAAA batteries inside the 9V (volume and capacity roughly go together)

1 AA = 1.5 V 4 AH = 6 WH
2 AA = 12 WH
9V = 9 V 0.5 AH = 4.5 WH

you may need to do hacks to get the white led going bright on 2.3 V (3 V less the 0.7 V on the transistor that makes it blink) or 3 V (if you use a mosfet). those hacks lower the efficiency but i think still the AAs are way better

to get max life use PWM (with N555 chip) instead of resistor. use a mosfet to drive the led. in the blinking make it like flashes - short time on and long time off