Ragone plot

Ragone plots can reveal information about gravimetric energy density, but do not convey details about volumetric energy density.

[3] Conceptually, the vertical axis describes how much energy is available per unit mass, while the horizontal axis shows how quickly that energy can be delivered, otherwise known as power per unit mass.

A point in a Ragone plot represents a particular energy device or technology.

The amount of time (in hours) during which a device can be operated at its rated power is given as the ratio between the specific energy (Y-axis) and the specific power (X-axis).

Consequently, the iso curves (constant operating time) in a Ragone plot are straight lines.