The AC adaptor / battery charger may either be attached directly to the instrument or, if used with a computer, to a short pigtail that is part of the X-Rite interface cable. In the event that the battery is not charging while connected to the power connector on the back of the instrument, try the following:
1) Disconnect the AC power adaptor from the back of the SP unit and then connect the AC power adaptor to the pigtail on the RS-232 end of the data cable (at the PC end) in an attempt to re-route power to the unit. If this does not deliver power to the unit proceed with step 2.
2) Verify that power is being delivered to the instrument by testing the voltage at the female end of the AC power adaptor with a volt meter. The voltage reported should reflect the values cited on the face of the charging unit.