3.20 state of charge SOC available capacity in a battery pack or system expressed as a percentage of rated capacity (3.15) 3.21 top off charge additional charge which eliminates possible SOC reduction after SCH at RT followed by thermal equilibration at a different temperature 3.22 supplier party that provides battery systems and packs EXAMPLE A battery manufacturer. 3.23 voltage class A classification of an electric component or circuit with a maximum working voltage (3.14) of ≤30 V a.c. (rms) or ≤60 V d.c., respectively Note 1 to entry: See ISO 6469-3. 3.24 voltage class B classification of an electric component or circuit with a maximum working voltage (3.14) of (>30 and ≤1 000) V a.c. (rms) or (>60 and ≤1500) V d.c., respectively.Note 1 to entry: See ISO 6469-3.