I have assumed that you want advise on an appropriate approach or method to keep the battery model as a generic model while allowing it to connect to charger/discharger models that have electrical domain interfaces.
Model Reference blocks in Simulink are designed for signal-based interfaces, so they do not natively expose Simscape conserving ports like electrical +/– terminals. To maintain a generic battery model with physical-domain connectivity, a more robust approach is to use Subsystem Reference or a library block instead of Model Reference. These options preserve Simscape physical ports at the top level, allowing direct connection to charger/discharger models without introducing signal conversion.
If modularity and reuse are priorities, you can encapsulate the battery core in a masked subsystem and manage parameters through a Simulink data dictionary or configuration sets. For scenarios requiring multiple charger/discharger variants, a Variant Subsystem can be used alongside the battery subsystem to keep the architecture flexible. If you must integrate with Model Reference for workflow reasons, an interface wrapper using Simulink-PS Converter and PS-Simulink Converter blocks can bridge the gap, but this changes the interaction from physical to signal-based, which may not be ideal for fidelity.

