Technical Analysis of Lithium-Iron Phosphate Batteries in Commercial Forklifts

Abstract

The efficiency of operational equipment in commercial and industrial applications can directly impact the revenue. Currently, lead-acid batteries are the standard for use in commercial forklifts and function well, but the forklift industry needs improvements on the power supply. Lithium Iron Phosphate (LFP) batteries have displayed improved characteristics in their thermal properties, charging time, and overall performance compared to the modern lead-acid when applied to forklifts. The use of LFP batteries can improve the operational efficiency of these machines. One of the great advantages of LFP batteries are their low cost in charging and low maintenance required, both of which lead to a lower total cost. LFP batteries also demonstrate a longer life cycle, a major proponent in the industry that leads to a higher cost efficiency. Using the BatPaC model provided by Argonne National Laboratory, an ideal LFP battery can be designed from a variety of inputs about the physical and chemical composition of the battery pack. In this article, three LFP batteries optimized to function as replacement forklift batteries will be detailed based on various factors. Each of the LFP batteries was optimized based on the following factors: total energy storage (kWh), total pack mass (kg), and total cost of cells ($/kWh). BatPac can construct a battery design based on the previously stated characteristics using the following inputs: target battery pack power at 20% SoC (state of charge), number of cells per module, number of modules per battery pack, parallel or series connections, and the pack capacity. Each of the optimized LFP batteries properly displayed a reduced weight and lower electricity cost than its lead-acid predecessors while increasing the overall efficiency of the battery pack.