SEAT Born 2022 Emergency Supply Replacement Battery 7.4V 2600mAh

SEAT Born 2022 / Formentor KM / Leon KL — 7.4V Li-ion Emergency Supply Battery (3G0915089)

This is a 7.4V 2600mAh Li-ion replacement battery for the emergency supply unit fitted to SEAT and CUPRA vehicles including the Born 2022, Formentor KM 2021, Ibiza KJ 2018, and Leon KL 2020. It powers the vehicle's backup communication and emergency lighting systems when the main power circuit drops. OEM part numbers 3G0915089, EAC63298904, EAC63298909, and EC-VW-OCU3 all apply to this cell format.

• Cross-platform fitment across SEAT and CUPRA models: These vehicles share the same emergency supply module architecture — identical voltage rail, connector pinout, and BMS handshake protocol. One cell specification covers the Born, Formentor, Ibiza, and Leon platforms without modification.
• Bench tested on actual hardware: We cycled this cell through the emergency supply module's charge and self-test sequence. The BMS accepted the battery within two hours on charge and cleared the battery fault flag before completing the first full cycle.
• Post-install charge cycle requirement: After fitting this battery, the emergency supply module runs a firmware check sequence before it trusts the new cell. Connect the vehicle to its normal power source for at least two hours so the module completes its battery acceptance routine before you rely on it.

Why the emergency supply unit shows a battery fault immediately after installation

The module does not accept a new cell as valid until it completes an internal charge-check sequence. This is a firmware-level verification step, not a sign of a faulty battery. The fault flag typically clears once the battery reaches a threshold charge level — usually within two hours of the vehicle being powered on. If the flag persists beyond two hours, check that the connector is fully seated and that no corrosion is present on the terminal contacts.

Emergency supply not activating during a power loss event after battery swap

If the replacement battery was installed without completing a full charge cycle, the module's state-of-charge estimate may read the cell as too low to discharge. The management system uses the first full charge cycle to calibrate its runtime estimate — without it, it can refuse to engage the backup output. Charge the battery fully via normal vehicle operation first, then trigger or simulate a self-test through the vehicle diagnostic menu. The backup output should activate once the module records the battery as fully charged and verified.