Blue Diamond high-frequency charger

Green Energy Concepts Inc says a new high-frequency forklift charger is the smallest and lightest in the industry, based on its output current. The charger measures 18.9 in. (48 cm) by 12.6 in. (32 cm).

Bassi Srl of Lugo, Italy manufactures the chargers for Green Energy Concepts. The new Blue Diamond-brand high-frequency model represents a game changer in the industry by applying a zero output current ripple (ZOCR) circuit, according to William Clayton, vice president of Salem-based Green Energy Concepts. Designers increased the charger's operating frequency above 100 kHz.

"In Italy, we do beta-testing with Toyota Material Handling, Linde, Carer and Icem and, in the US and Canada, with Raymond, Crown, Hyster, Yale and Toyota," Clayton says. "All our chargers are specifically designed for electric forklift trucks and other electric vehicles for industrial and commercial applications."

The ZOCR circuit's benefit is the complete elimination of the residual ripple on the output current that the charger generates. An ideal battery charger operates with a perfect current source that generates a controlled constant regulated DC current, but, in reality, the output current of a high-frequency charger is not perfectly constant because a residual oscillation, or ripple, affects it at the switching frequency. The first effect is an unwanted rise of the temperature of the battery during charging, and a second effect involves a mechanical vibration of the battery plates that may have the same effect of an ultrasonic cleaner that removes the active material.

Initial design of the Blue Diamond high-frequency chargers was for lead-acid batteries, but a digital control configuration allows interconnection with all existing and future lithium battery types.

The Bassi company was founded in 1974, and its core business has been forklift battery chargers. "The development work was started more than 40 years ago," Clayton says. The partnership between Bassi and Green Energy Concepts, which employs 10 staff, began in 2006.

Bassi has a global install base of more than 300,000 forklift battery chargers, of which more than 100,000 operate in North America.