NOVELTY - The method involves determining a position of a coupling structure support portion (172a) relative to a position of a coupling assembly platform portion (172b). Torque applied by a wheel to an underlying surface is controlled by commanding a coupling structure to vary the position of the support portion relative to the platform portion while maintaining the platform at desired orientation. A specific position of the support portion relative to the platform portion is specified to control the torque applied by the wheel to the underlying surface to achieve desired speed for a vehicle.    USE - Method for controlling speed of a vehicle e.g. dynamically-balancing vehicle and battery powered vehicle (all claimed). Can also be used for electric vehicle.    ADVANTAGE - The method enables ensuring the coupling structure to command positions, thus maintaining balance of the vehicle. The method enables preventing unwanted turning of the vehicle and accounting performance variations between two motors of the vehicle. The method enables specifying the specific position of the support portion relative to the platform portion to control the torque applied by the wheel to the underlying surface, thus achieving the desired speed for the vehicle, and hence preventing vehicle from exceeding the maximum speed limit. The method enables passing current capability to an effort limiter, which limits the slide position to keep margin between the commanded current and the current capability of a system, thus maintaining balancing and steering capability. The method enables maintaining pitch stability. The method enables helping to detect high battery resistance condition quickly.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following:    (1) a vehicle comprising a support    (2) a method for maintaining a balancing margin for a dynamically-balancing vehicle    (3) a dynamically-balancing vehicle comprising a support    (4) a method for determining motor current capability for a battery powered vehicle    (5) an apparatus for determining motor current capability for a battery powered vehicle comprising a measurement module    (6) a method for estimating electrical state of a battery providing power to an electrical load    (7) an apparatus for estimating electrical state of the battery providing power to an electrical load comprising a measurement module.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a vehicle.    Vehicle (100)    Enclosure (102)    Support (104)    Ground-contacting element (110)    Coupling structure support portion (172a)    Coupling assembly platform portion (172b)