Lengthy idle periods with a high charge level may result in an accelerated ageing of the high-voltage battery.
Exhaustive discharging caused by the battery being idle for lengthy periods can damage the high-voltage battery.
Recharge the high-voltage battery if the charge level is insufficient.
You can check the charge level of the high-voltage battery in the multimedia system More
Depending on the national version, your vehicle is equipped with one of the following vehicle sockets.
You can charge the high-voltage battery with both alternating current (mode 2 or 3) and direct current (mode 4).
Socket for charging with alternating current 
Socket extension for charging with direct current
When using a CCS (Combined Charging System) charging cable to charge with direct current, both areas of the vehicle socket are covered by the charging cable connector.
Charging through recuperation while the vehicle is in motion
Stationary charging with alternating current via:
Mains outlet (mode 2)
Wallbox (mode 3)
Charging station (mode 3)
Stationary charging with direct current via:
Charging station (mode 4)
The high-voltage battery can be charged in a nominal voltage range from 100 V to 400 V.
It is recommended that you charge the high-voltage battery at a wallbox or charging station due to the improved charging performance offered.
High or low outside temperatures
Electrical auxiliary consumers in the vehicle being switched on, e.g. operating the climate control system
Extended periods without charging
High or low outside temperatures
Extended periods without charging
The maximum available charging current of the wallbox or power supply equipment
The charging current set (mode 2) in the multimedia system More