Depending on your specific powertrain version, the 12-volt battery in your Seat Leon is positioned either securely inside the engine compartment or tucked away within the luggage compartment (specifically in PHEV hybrid variants). The health and charge state of the 12-volt battery are routinely inspected and, if deemed necessary, replaced as an integral part of scheduled maintenance work.

All technical work, handling, and servicing associated with vehicle batteries require specialized professional knowledge and proper safety equipment.

Always entrust battery-related tasks to an Official SEAT Service or a specialized battery workshop. Attempting uncertified work creates a severe risk of chemical burns or an unexpected battery explosion! The sealed battery housing must never be opened under any circumstances. Never attempt to check, alter, or change the internal fluid electrolyte level of the battery. Doing so will release volatile, explosive gases from the cells that could ignite and cause a violent explosion.

Battery warning indications

Always wear certified protective goggles when handling the battery.

Battery electrolyte acid is extremely corrosive and hazardous. Always wear acid-resistant protective gloves and eye protection.

If any accidental splashes of electrolyte come into contact with your skin or eyes, rinse the affected area immediately with plenty of clean water.

The 12-volt battery should only ever be charged in a thoroughly well-ventilated area. Extreme risk of explosion!

Always keep children and pets far away from corrosive battery acid and the battery unit itself.

Always read and meticulously follow all guidelines in the owner's instruction manual.

Automatic shutdown for electrical consumers

After the drive system of your Seat Leon is deactivated, the 12-volt battery may experience a drop into a low state of charge if the vehicle remains parked for an extended period, if high electrical consumers are operated while stationary, or if the outside ambient temperature is extremely low.

To ensure that the powertrain can successfully start up again, the smart on-board energy-management system may automatically implement the following protective measures when battery charge levels run low:

• The power output of the largest electrical consumers is dynamically restricted or switched off completely if necessary, and online infotainment and connectivity services will be temporarily disabled.
• The power supply to the 12-volt accessory sockets may be briefly interrupted when the drive system is subsequently started.

WARNING Working directly on the 12-volt battery and vehicle electrical system can cause severe chemical burns, electrical fires, and dangerous electric shocks. Always read, understand, and strictly observe the following warnings and safety precautions before performing any work on the battery:

• Before beginning any work on the 12-volt battery of your Seat Leon, switch off the ignition completely, turn off all electrical consumers, and disconnect the negative battery cable first.
• Always keep children and unauthorized persons strictly away from the 12-volt battery electrolyte and the battery unit.
• Always wear appropriate eye protection and heavy-duty protective gloves.
• Battery electrolyte is highly corrosive and destructive. It can cause severe skin burns and permanent blindness. When handling the 12-volt battery, protect your hands, arms, and face from any potential acid splashes.
• Never smoke while working on or near the battery, and never perform maintenance in the vicinity of naked flames, sparks, or glowing heat sources.
• Take care to avoid generating static electricity sparks caused by electrostatic discharges, such as when handling electrical cables, tools, and synthetic devices.
• Never bridge or short circuit the battery terminals under any circumstances.
• Never use a damaged or cracked 12-volt battery. Damaged batteries can rupture or explode. If the battery casing is compromised, replace it immediately.
• Never attempt to use or jump-start a frozen 12-volt battery. When deeply discharged, a battery can freeze solid at temperatures hovering close to 0ºC (+32 ºF). If a 12-volt battery is suspected of being frozen, it must be replaced immediately.

NOTICE Do not expose the 12-volt battery of your Seat Leon to direct, intense sunlight for prolonged periods.

• Ultraviolet (UV) radiation can degrade and structurally damage the plastic battery casing.

NOTICE If your vehicle is not going to be driven or used for a long period of time, protect the 12-volt battery from freezing temperatures.

• An undercharged battery can freeze solid in cold weather and suffer irreparable internal structural damage as a result.

Note After starting the engine with a deeply discharged battery, a newly replaced 12-volt battery, or following an emergency jump-start, certain personalized system settings (such as the digital clock time, calendar date, individualized driver comfort profiles, and specific infotainment programs) may be reset, incorrectly configured, or deleted.

Note During harsh winter conditions, overall battery cranking and starting power is naturally reduced; if necessary, the 12-volt battery should be proactively recharged using an approved battery charger.