How can you determine the length of time that equipment can be powered from a battery?

To determine the length of time that equipment can be powered from a battery, the approach of dividing the battery ampere-hour rating by the average current draw of the equipment is fundamental.

The battery's ampere-hour rating represents the total current the battery can supply over time before it is depleted. By dividing this rating by the average current draw of the equipment, you obtain the total operational time. This calculation provides a straightforward understanding of how long the battery can sustain power to the device, as it directly relates the battery's energy capacity to the power demand of the equipment.

In this context, the other methods presented do not accurately measure the time duration for which equipment can run on the battery. One of those methods involves dividing the watt-hour rating of the battery by the peak power consumption, which can lead to misleading results because peak power consumption may not reflect the average operational current. Another option suggests multiplying the watts per hour consumed by the battery power rating, which doesn't properly conform to standard calculations of time and lacks relevance to the current drawn. Lastly, the suggestion to multiply the square of the current rating of the battery by the input resistance of the equipment does not connect logically to determining run time and introduces unnecessary complexity without yielding useful duration information.