hey how do i work out how many led's i can hook up to a 9v battery that will last at least a day?

i want to link together as many blue led's on one circuit as i can i was thinking a couple of 9v batteries and a bunch of led's together, but i dont know much about led's :)

ANGRY_CLOUD (author) 8 years ago
ty all :) ive been reading up loads on led's think ive got a good setup sorted, ill tell ya if it all goes wrong haha
lemonie8 years ago
No one posted this yet?

jj378 years ago
volts*amps=watts so a 9 volt is 9*0.595=5.355 watt hours =~0.2 watts per hour for 24 hours so you want an led that will run at ~0.2 watts if you have a bigger led you could change the resistor.

two questions
1. what led do you have?
2. is the nine volt alkaline?
jj37 jj378 years ago
also check out this it runs at about 0.24 watts so if you could control the voltage this would work