The present invention provides a connection arrangement for releasably connecting an electrical device and a power control module, the electrical device including an electrically powered functional component, the power control module including a device for controlling the supply of electrical power to the functional component when the electrical device and the power control module are connected. The connection arrangement includes a first connecting portion associated with one of the electrical device or the power control module and configured to interengage with a second connecting portion associated with the other one of the electrical device and the power control module. The first connecting portion including a first locking member and the second connecting portion including a second locking member, wherein when the first and second connection portions are engaged the first and second locking members are movable relative to each other between an unlocked position in which the first and second connection portions are separable and a locked position in which the first and second connection portions are locked together. Preferably, the electrical device is a power tool module.