An illustrative battery retaining assembly comprises a retaining plate, and a casing including mounting devices. One of the mounting devices may include a hinge device, and another of the mounting devices may include a latch device. The retaining plate includes engagement portions engageable with the mounting devices, such that the retaining plate may be mounted to the casing. One of the engagement portions may include a channel engageable with the hinge device, and another of the engagement portions may include a catch engageable with the latch device. The mounting devices and engagement portions may be configured to enable the retaining plate to slide at an oblique angle with respect to the casing, to provide a variable separation distance between the casing and the retaining plate.