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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? Answered

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 :)

Tags:led

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ANGRY_CLOUD (author)2009-09-07

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

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jj37 (author)2009-09-06

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?

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jj37 (author)jj372009-09-06

also check out this it runs at about 0.24 watts so if you could control the voltage this would work
http://www.sparkfun.com/commerce/product_info.php?products_id=8860

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