The disclosure describes an improved apparatus for converting a manually-powered wheelchair into an electrically powered wheelchair. The apparatus comprises a frame, at least one powered drive wheel, at least one motor powering said drive wheel, and at least one power base axle receiver capable of connecting with an existing axle receiver of a manually powered wheelchair. The apparatus further includes an anti-tip/counterbalance mechanism to prevent a user from losing control and falling backward when the power base attachment is connected. The apparatus uses the existing axle receiver of a manual wheelchair as a universal connection point and to maintain the center of gravity for a user.
