# DC/DC Controller: Role and Selection for Cluster Management DC/DC solves voltage decoupling and enables fine cluster management. Bidirectional buck-boost, heterogeneous batteries and SOC balancing with SP210HCDC, SP120/60HCPV. What DC/DC solves When the challenge is "how to connect different battery voltages to one DC bus", a bidirectional DC/DC is the typical tool: it decouples voltage and enables multi-cluster management. VGRID DC/DC matrix [SP210HCDC](/en/product/sp210hcdc): 210kW bidirectional buck-boost, 200–950V wide input, paralleling. [SP120/60HCPV](/en/product/sp120-60hcpv-sp105hcdc): 60/120/105kW, wide-voltage DC coupling, heterogeneous batteries and SOC balancing. Selection points Check input/output voltage range, max current, paralleling and cluster management. Plug-in PCBA sealed, airflow isolated, ≥10-year life. DC/DC is key for large PV-storage and mobile storage. ## Do I need both DC/DC and MPPT? Depends on topology. MPPT handles PV combiner; DC/DC handles voltage decoupling and cluster management; DC-coupled systems often use both. ## How to connect heterogeneous batteries? Bidirectional DC/DC decouples voltage; each cluster is managed independently, accepting different voltages/health. ## Is SOC balancing by DC/DC or PCS? Cluster SOC balancing can be by PCS or DC/DC depending on architecture (see Zambia project). ## Role of DC/DC in large systems? Enables independent cluster management and voltage decoupling, improving flexibility and safety.