“It doesn’t say what charges the battery; I’m assuming the diesel engine up front.”
Article: “The trailer can be charged at either end of the journey, taking 10.5 hours on an AC connection, or as little as 45 minutes using a 350-kW DC fast charger.”
Hybrids are a logical step for many trucks that return to base every night. Like a beer truck or any package delivery service. Good for users with lots of starts and stops and short runs.