This recommended practice defi nes the areas of recommended knowledge for installers and maintainers of stationary standby batteries (primarily lead-acid and Ni-Cd standby batteries) and related systems to the extent that they aff ect the battery, personnel safety and reliability of any related systems. Designing the dc system (including any connected ac inverters) and sizing of the dc battery charger(s) are beyond the scope of this recommended practice. While some of the battery information covered by this practice applies to small off - grid cycling applications, information relative to large energy storage cycling applications is limited.