Particularly in shift operation, it is often the case that all forklift trucks within a fleet call at their charging stations at the same time. This leads to increased energy consumption – especially at the start of the charging process – which can result in expensive peak currents. Should this occur on a regular basis, consumption will exceed the annual quota agreed with the energy supplier. This can result in supplementary payments and additional provision costs. Many companies respond by disconnecting production machines or even entire warehouses and production areas from the grid and shutting them down when peak currents occur. Disruptions to the company's entire operations can thus be traced to the simultaneous peak current consumption of the battery charging systems.