Forklift with a lithium-titanate battery during a lifting/lowering cycle: Analysis of the recuperation capability

• Recuperated energy has a positive effect on the reduction of the energy consumption.
• Recuperated energy can increase operation time of the forklift.
• The simulation shows that direct electric pump drive system has advantages.
• Described speed control of forks can improve energy consumption of the forklift.

Opportunities of storing electric energy recovered from an electro-hydraulic forklift truck are studied with a lithium-titanate battery as energy storage. Instead of a traditional valve control, the lifting system is controlled directly with an electric servo motor drive and a hydraulic pump capable of operating also as a hydraulic motor during potential energy recovery. The paper describes the proposed speed control method of forks to improve the energy efficiency characteristics of the forklift, including the operation time and lifetime of the energy storage device. The analysis results for the proposed systems are compared for different battery sizes from the life cycle point of view.