How Long Does It Take to Charge a Commercial Truck Battery

When it comes to charging commercial truck batteries, the answer is not as straightforward as it might seem. The charging time depends on several key factors. Let's explore each of these factors to give a better understanding of how long it takes to fully charge a commercial truck battery.

Factors Influencing Charging Time

1. Battery Capacity

The size of the battery plays a crucial role in determining the charging time. Larger batteries hold more charge, necessitating more time to recharge. This is why some commercial trucks can take longer to charge than others. For example, the Freightliner eCascadia Class-8 with a 475 kWh battery can charge 80% in 90 minutes, whereas the eM2 Class 6–7 with a 315 kWh battery can achieve 80% charge in just 60 minutes.

2. Current Status of the Battery

The amount of charge remaining in the battery at the start of charging also affects the charging duration. If the battery is almost completely drained, it will take longer to fully charge than if it already has a certain percentage of charge.

3. Charger Capacity

The power output of the charger is another critical factor. High-power chargers can charge batteries faster, given that they can supply a larger current to the battery. For instance, a 350 kW charger is significantly faster than a 100 kW charger.

4. Tapering Regime During the Charging Process

The tapering regime, or the rate at which the charging slows down as the battery nears full charge, also impacts the overall charging time. Some chargers use a rapid charging phase followed by a slower, more precise charging phase to avoid overcharging and ensure a safe topping off of the battery.

Real-World Examples

Freightliner eCascadia: The Freightliner eCascadia, with its 475 kWh battery, can charge 80% in 90 minutes, providing 380 kWh of range for a significant 200 miles. This is a substantial amount of range, but it comes with the trade-off of a longer charge time.

Freightliner eM2: The eM2, with its 315 kWh battery, is quicker, charging to 80% in just 60 minutes, providing 252 kWh of range for 185 miles. This is nearly as much range as the eCascadia but in a third of the charging time, making it a more time-efficient option for operational needs.

Challenges and Solutions in Commercial Truck Charging

Despite the advancements in battery technology, commercial trucks still face challenges, particularly in long-haul over-the-road (OTR) operations. Bigger trucks have heavier batteries, which are not ideal for extended distance travel due to the added weight. This is where partnerships come into play. Daimler is collaborating with Volvo to bring fuel-cell trucks to the market by 2030, anticipating the 2050 regulatory deadlines.

Currently, chargers max out at 350 kW and require liquid-cooled charging cables. This technology is not only efficient but also scalable. Daimler's Electric Island Experimental Charging Station, located in Swan Island Industrial Park, Portland OR, is a prime example. This station can scale up to a megawatt with simple transformer upgrades, supporting all charging standards except Tesla on several networks. It's one of the cheapest charging stations along the I-5 corridor, offering a cost-effective solution at 15 cents per kWh.

Conclusion

The charging time for a commercial truck battery depends on multiple factors, including battery capacity, charger power, and the battery's initial charge status. While advancements in technology strive to address these challenges, the transition towards more efficient and practical truck charging solutions continues to evolve. Partnerships and innovations in fuel-cell technology and charging infrastructure play a vital role in making commercial trucking more sustainable and efficient.