Technical explanation
The BMS estimates SOC and applies protection. A displayed 100 % does not necessarily mean no internal margin. Temperature, power and aging affect energy actually available.
Definition · Storage
SOC (State of Charge)Battery charge level in %
TL;DR
SOC indicates estimated battery state of charge. Limits, reserves and safety margins depend on the system; follow manufacturer instructions.
Definition
State of Charge expresses available charge relative to a reference capacity. The BMS display may represent a usable window defined by the manufacturer.
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Unit
% charge
📊
Usable capacity
Per datasheet
⚡
Backup reserve
Set for demand
🛡️
BMS limits
Manufacturer instructions
Swiss context
Specify nominal capacity, usable capacity and backup reserve in the quote. A reserve reduces energy available for self-consumption; no single setting suits every household.
Related terms
Related guides
FAQs — SOC (State of Charge)
Should I leave my battery at 100% all the time?+
Follow manufacturer guidance, including any calibration or balancing cycles. Do not substitute a general 10–90 % rule.
Is the displayed capacity the usable capacity?+
Distinguish nominal kWh, usable kWh and SOC percentage. Check exact model and generation: a LUNA2000 or other brand capacity does not apply to every model.
Sources & method
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