(from the manual)
Energy Saving Mode
When the high voltage battery is low on power, a message will appear on the infotainment display, prompting the
driver to enable the energy saving mode.
When the energy saving mode is enabled, the vehicle will operate on the minimal energy consumption. The power of the
air conditioner is limited. The energy regeneration level is automatically adjusted and fixed to "strong".
When the energy saving mode is turned off, the energy regeneration returns to the former-selected level. The energy saving
mode can be turned on and off on the infotainment display