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 comprising a grid framework structure supporting a plurality of tracks arranged in a grid pattern to define a grid structure above the one or more stacks of containers, the grid pattern comprising a plurality of grid cells and each of the one or more stacks of containers being located within a footprint of only a single grid cell, the load handling device comprising:

• A) a driving mechanism operatively arranged for moving the load handling device on the grid structure,
• B) a vehicle body having a footprint that, in use, occupies substantially only a single grid cell in the storage system, said vehicle body housing:
• i) a rechargeable power source for powering the driving mechanism;
• ii) a first space and a second space, the first space being configured for accommodating a container and the rechargeable power source is housed in the second space, the second space being directly above the first space;
• iii) a lifting device comprising a lifting drive assembly and a grabber device configured, in use, to releasably grip a container and lift the container from the stack into the first space, wherein the lifting device comprises a motor that is configured to raise and lower the grabber device;
• 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;
• wherein the rechargeable power source and the lifting drive assembly are mounted in the same horizontal plane.