I'm building a battery to drive a small 12V motor which is rated to draw max 7A.
The battery has the following stats:
- Nominal voltage: 14.4V
- Capacity: 20.4Ah
So I calculated that the energy should be 293.76Wh.
So I understood the discharge time should be calcuated as:
Energy/(Voltage * Current)
Since the motor is rated for max 15V, which is below the 16.8V max of the battery, I will use a buck converter to bring the voltage down to 12V.
So my question is, would the calculation then be:
293.76Wh / (12V * 7A)
Or, do I use the nominal voltage of the battery in the calculation?, i.e.
293.76Wh / (14.4V * 7A)