Hi.
I am trying to make simple torch by using 1watt smd and a battery that says 3.6v power output and is 800mAh.
kindly tell me how to calculate the run time of smd (till it goes completely off).

Thanku so much in advance

 

Assuming you are meaning an LED. provide the data sheet for the LED, or give the forward voltage of the LED and the current level you are using to drive it. i.e. - 3.0 volt and 300 mA. would run for about 20-30 minutes before the battery voltage became to low to operate the LED.

 

Who manufactured the battery and what is the model number?