Battery knowledge · Units and electrical basics
Electric charge
The quantity a battery’s capacity actually counts: how many electrons, or lithium ions, have passed. It is measured in coulombs or ampere-hours and is conserved, which is why charge in must equal charge out plus losses. [1]
- Abbreviation
- Q
- Unit
- C, Ah
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.