Battery knowledge · Capacity, energy, power and ratings
Ragone plot
A log–log chart of specific power against specific energy on which each storage technology occupies a region. Capacitors sit high and left, batteries lower and right, and a single cell traces a curve as it is discharged faster.
Example
Specific power versus specific energy
The chosen example is 10 Ah at a 10-hour rating, 3.7 V constant voltage and 0.1 kg mass. At higher current, power rises while usable specific energy falls when the exponent exceeds 1.
An illustrative cell curve, not technology-region data or a fitted lithium-ion result. The empirical exponent controls the rate effect.
Explore the graph
A Ragone chart uses logarithmic axes to compare energy and power per unit mass.
The chosen example is 10 Ah at a 10-hour rating, 3.7 V constant voltage and 0.1 kg mass. At higher current, power rises while usable specific energy falls when the exponent exceeds 1.
Specific power = VI / mass; specific energy = VIt / mass
Illustrative model. An illustrative cell curve, not technology-region data or a fitted lithium-ion result. The empirical exponent controls the rate effect.
Use in Lemonergy
Separate nameplate ratings from test results.
This is a reference concept. No executable Lemonergy block has been verified for this term.
References & further reading
Further reading on this topic
These sources provide broader context; they are not presented as citations for every statement in this entry.
- The International System of Units (SI), 9th edition
Bureau International des Poids et Mesures · 2026
Topic background · Definitions of SI units and coherent derived units; 2026 revision.
- Battery Test Manual For Electric Vehicles, Revision 3
Jon P. Christopherson · Idaho National Laboratory · 2015
Topic background · Performance characterization, pulse resistance/power, life testing and reference performance tests; historical 2015 edition.