Run-time formula?

[John Frederick]

New guy question here:

I saw a simple formula posted here for estimating a light's run-time based on the light's amp draw and the battery's voltage and capacity. Like a d.a. I didn't mark the thread

Could someone please tell me what it is. If I remember correctly, it was Brock's formula. Thanks!

 

[Deleted member 684]

Take the current draw of the bulb divide it by the capacity of the battery. Multiply the answer by 0.7 to get a estimated run time.

The 0.7 is because you are not going to use a extremely dim light. Adjust as you see fit.