Battery Terminology Glossary

C

C-Rate

Charge or discharge current relative to battery capacity. 1C means full charge/discharge in 1 hour;...

CAES (Compressed Air Energy Storage)

Energy stored by compressing air in underground caverns or vessels; air is later expanded to...

Calendar Life

Battery lifetime considering aging over time even without significant cycling. 

Capacity Market / Resource Adequacy

Markets or mechanisms that pay for availability of capacity (MW) to ensure reliability, often important...

CAPEX (Capital Expenditure)

Upfront cost to build and commission the storage system. 

Cell

Smallest electrochemical unit of a battery (e.g., cylindrical, prismatic, pouch). 

Containerized BESS

A BESS housed in a standardized container (e.g., 20 ft / 40 ft), including batteries,...

Cycle

One full charge and discharge of a battery (often defined from one SoC level back...

Cycle Life

Number of cycles until the battery reaches a specified end-of-life SoH (e.g., 60–80% of original...