What voltage are substation batteries, and can I standardise across a mixed fleet?

Bank voltages across Australian distribution fleets span 6 V to 250 V DC, with 125 V DC the most common and capacities up to around 400 Ah, per AusNet’s published fleet data. Legacy 32 V and 48 V systems are common, and Sydney Water’s current specification nominates 48 V DC for new installations with 32 V and 110 V retained only for existing sites. Standardising is worth doing for spares, testing equipment and technician familiarity, but it is an asset-replacement programme rather than a retrofit, the DC distribution, protection settings and equipment input ranges all follow the bank voltage.