SOC
SOC in the SpeicherCampus context: the battery's current state of charge. Technically, the term is usually described as State of Charge.
What does SOC mean?
State of Charge is the battery’s current charge level in per cent — the storage system’s fuel gauge. 100 % means full, 0 % means empty within the released limits (the BMS always keeps a protective reserve below that).
The SOC is the EMS’s central control variable: operating strategies like “hold a backup reserve”, “make room before the midday peak” or “charge cheaply at night” are ultimately SOC rules.
What matters in practice
- define SOC windows: daily cycling, reserves, protection limits
- SOC accuracy depends on the BMS — drift is calibrated periodically
- watch the SOC curve in monitoring: it exposes planning errors immediately
- manufacturers specify separate SOC requirements for maintenance and transport
Practical example
Monitoring shows the system sitting at 100 % for hours every afternoon. Diagnosis: capacity too small or the charging window wrong — here the PV was stronger than planned. Adding a second cabinet turned the permanently-full system back into a working asset.
The SpeicherCampus perspective
SpeicherCampus uses SOC curves from monitoring as an early indicator: they show whether design and reality match.