Power systems are the core heartbeat of any advanced vehicle. Reliability and flexibility of these systems are therefore of the highest priority. This Phase 1 project proposes a highly efficient and modular isolated bidirectional DC converter for battery energy applications. GridBridge is utilizing advanced DC converter topologies for modernization of the today's electrical distribution power grid and will translate work into high priority NASA power system applications, demonstrating transferability, robustness, and scalability. This bidirectional DC converter offers an extremely high power density and will utilize a novel hybrid resonance and PWM technique to achieve. It will also offer NASA the flexibility for many power system topologies, including: distributing large single cells throughout the vehicle, use of smaller cells in a centralized location, or a combination banked smaller cells distributed throughout the system. This is accomplished through independent charging and discharging control of state-of-charge and state-of-health for each battery module, inherent active maximum current limit and short-circuit protection, and ease of module balancing.