Battery Management System and its Applications

16 BMS for a Fork-Lift

In Europe, about half a million commercial vehicles are sold every year. Around half of these vehicles are now powered by lead-acid batteries. Lead-acid batteries are cost-effective, but they are heavy, show poor performance, and offer a shorter life. In addition, lead-acid batteries require a relatively large maintenance effort and have poor energy efficiency, particularly when partial discharge (shallow cycles) occurs. Lithium-iron-phosphate batteries behave differently. They produce higher efficiency, lighter weight, and a longer life, which make them increasingly attractive as an alternative. Lithium-ion (Li-ion) battery systems have been developed specifically for the conveyor belt area, with integrated battery management and adapted charging infrastructure. Use of Li-ion batteries has an economic advantage in the case of a precise lifetime cost analysis.

16.1 Lithium-Iron-Phosphate Batteries for Fork-Lifts

The lithium-iron-phosphate accumulator is the most suitable development of the Li-ion battery for fork-lift applications. Iron phosphate or LiFePO₄ is used as the cathode material. Iron phosphate can be produced less expensively than cobalt oxide, which is commonly used for Li-ion batteries. Even more problematic, cobalt is supplied by only a few countries, which makes this raw material more vulnerable to tremendous price fluctuations due to commodity speculation. Such imponderables are less likely to happen for iron phosphate as the raw materials ...