Here are some tips:① Check if the vacuum is properly installed—it will beep when placed correctly. Reinstall the vacuum if there is no beep.② Make sure the auxiliary battery is fully pushed in until its icon flashes.③ Check that the robot vacuum has docked correctly—it beeps when in place. Also, check for debris if an error message pops up.④ Check that the plug is fully inside the outlet.⑤ Unplug the unit and wipe off any debris from the charging terminal with a dry cloth.⑥ Your unit may not charge if the temperature is below 41°F (5°C). Try charging again after it’s above 41°F.