this isnt homework but its something im trying to figure out. how would i calculate if i left a light on how long it would take to drain its source (battery)? thanks

 

Originally posted by silver6g72@Sep 18 2005, 01:51 AM
this isnt homework but its something im trying to figure out. how would i calculate if i left a light on how long it would take to drain its source (battery)? thanks

[post=10432]Quoted post[/post]​

A bulb pulls the power its rated at if its used at the voltage intended. So if you have a 5v, 1 watt light, then it pulls 1 watt (0.2 amps @ 5 volts)

Batterties have a power rating given in Ampere Hours. i.e. How many hours can the battery push out 1 amp. So if you have a 5 watt bulb and a 10 ampere hour battery.

10/0.2 = 50 hours of use given 100% efficiency.

 

thanks man for your reply