The trucking industry is facing a pivotal moment in its journey towards decarbonization. Coined as the 'messy middle' by the North American Council for Freight Efficiency, this phase signifies the complexity of transitioning to cleaner technologies like lithium-based solutions while waiting for full electrification feasibility. Fleet operators are encouraged to act promptly to stay competitive and reduce their carbon footprints. Advanced lithium-ion battery systems, particularly all-electric auxiliary power units (APUs), are highlighted as a bridge to cleaner operations in the present. Lithium-based APUs provide fleets with a pathway to enhance fuel efficiency, lower emissions, and decrease operational costs without the need for immediate full electrification. These systems, especially LiFePO4 batteries, are well-suited for auxiliary applications, offering benefits such as powering cab comfort systems, reducing idling, and contributing to sustainability efforts. The road ahead for the trucking industry involves embracing hybrid solutions that combine traditional powertrains with advanced lithium technologies. By integrating lithium-based systems, fleets can start the decarbonization process efficiently. However, infrastructure development, particularly charging stations, is crucial for widespread adoption. Collaboration among industry stakeholders is essential to navigate the transition to zero emissions successfully.