Level 2 Charger
Level 2 chargers use alternating current, which compatible electric buses will convert to usable power through an onboard inverter. They operate at voltages of either 208v or 240v. Usually, a Level 2 charger will deliver between 10-20 additional miles of range per hour. Level 2 chargers use a connector type known as the J1772 connector pictured below.
Electric buses batteries only store power as Direct Current (DC), therefore any district school bus using AC charging will need to have an onboard inverter. Most buses come equipped with a CCS port, which accommodates both AC and DC charger heads.
Individual Level 2 station installations plus equipment can range from ~$15,000 to $35,000 or more installed
Direct Current Fast Charger (DCFC)
DCFCs typically operate at higher power than AC chargers (up to 350 kW), and certain bus manufacturers, such as Thomas Built, will only support DC charging. Standard DCFCs require three-phase 480v potential, but at lower capacities can operate on 208v. Usually, DC chargers will deliver around 150 miles of range per hour. Most DC chargers use the Combined Charging System (CCS) connector type pictured below. Unlike with AC chargers, electric school buses do not need an onboard inverter to transform their power. Instead, the DC charger will have an inverter built into the station that will transform AC power from the grid into DC power for use by the bus.
DCFC stations can range from $30,000 installed to $80,000 or more depending on such variations as the distance of the chargers from the service panel, any utility relocations needed, and the cost of trenching, conduit, and other materials and labor