[ot] [sdiy] Battery questions

[Roy J. Tellason]

On Monday 17 January 2005 12:05 pm, Robotboy8 at aol.com wrote:
> Two questions.  Firstly, how long can I expect two AA batteries to last
> when connected to a single LED (no other circuitry)?  And will the color of
> the LED matter?

No current limiting resistor?  That LED isn't gonna last real long...

Got one in there?  Then it depends on what you decide is an appropriate 
current level for the LED,  what gives you an acceptable level of brightness.  
And,  since different colors have somewhat different voltage drops,  and 
different brightnesses for a given current,  this is gonna matter too.  Plus 
whether you are talking a clear or diffused package,  and whether you're 
talking about one from a radio shack assortment or somewhere else.

Oh,  and it depends on whether you're talking about fresh alkaline batteries 
or some other kind.

Try it,  see how much current you're drawing,  and we can figure it from 
there.