Hi, The number 2 displayed denotes that there is no charge voltage to the chair. The stairlift operates on 2 x 12v batteries and picks up positive supply from a copper strip/busbar running down the side of the rail, the negative is via the toothed rack. You can check the voltage with a multimeter by selecting DC voltage and placing the red probe on the copper strip and the black probe on the toothed rack. If voltage is around 30V D.C then the charger is fine and problem lies within the chair and may be the carbon brush which picks up the charge from the copper strip and is hidden by a small clip on cover on the side of the carriage.
These chairs do suffer from various failures including problems with the charger.
DOLPHINDAVE
September 2011