Stability of a Load Handling Device in a Storage System

A load handling device for lifting and moving one or more containers stacked in a storage system with a grid framework structure supporting a plurality of tracks arranged in a grid pattern. The load handling device includes a driving mechanism, and a vehicle body having a footprint that occupies a single grid cell in the storage system. The vehicle body housing includes a rechargeable power source, a first space configured for accommodating a container and the rechargeable power source is housed in a second space, and a lifting device to releasably grip a container and lift the container from the stack into the first space, wherein the rechargeable power source is arranged above the first space such that the centre of mass of the load handling device is in the second space.