Battery knowledge · Units and electrical basics
Coulomb
The SI unit of electric charge; one ampere flowing for one second. Battery engineers prefer the ampere-hour, which is 3600 coulombs, because cells deliver their charge over hours. [1]
- Abbreviation
- C
- Unit
- C
Example
C-rate, current and duration
5 Ah × 1C = 5 A. Ideal duration: 1 h (60 min).
Voltage cutoff, losses, temperature and rate-dependent capacity are excluded.
Explore the graph
A C-rate becomes an actual current only when capacity is known.
5 Ah × 1C = 5 A. Ideal duration: 1 h (60 min).
I = Q × C-rate; t_ideal = 1 / C-rate
Illustrative model. Voltage cutoff, losses, temperature and rate-dependent capacity are excluded.
Use in Lemonergy
Use consistent units and cell/pack basis.
This is a reference concept. No executable Lemonergy block has been verified for this term.
References & further reading
Technical references
- The International System of Units (SI), 9th edition
Bureau International des Poids et Mesures · 2026
Technical reference · Definitions of SI units and coherent derived units; 2026 revision.