Skoda Fabia PJ 2022 Emergency Supply Compatible Battery 7.4V 3400mAh

Skoda Fabia PJ 2022 — 7.4V Li-ion Replacement Battery (3G0915089)

This is a 7.4V, 3400mAh Li-ion replacement for the emergency supply battery used across several Skoda and Volkswagen Group vehicles. It fits the Fabia PJ 2022, Kamiq NW 2019/2020, Karoq ND 2018, and six additional models sharing the same emergency module. The battery maintains hazard light and door unlock functions when the main vehicle power is lost.

• Shared across Skoda and VW Group emergency modules: The Fabia PJ, Kamiq NW, and Karoq ND platforms use the same 7.4V emergency supply unit with an identical connector, cell format, and BMS handshake. One part number covers all of them because the module firmware treats them identically.
• Bench tested on actual hardware: We ran this cell against the emergency module's BMS acceptance sequence. The protection circuit passed the charge-termination check at 8.4V, and the discharge floor triggered correctly before cell voltage dropped below 6.0V under a simulated load.
• Module initialisation after swap: The emergency supply module in these vehicles requires a full charge cycle before it will commit a runtime estimate to memory. Install the battery, connect the vehicle to a charger or run the engine for a full charge cycle, then trigger the module's self-test via the vehicle diagnostic menu or ignition cycle sequence.

Why the emergency module shows a battery fault immediately after installation

The Skoda emergency supply module runs a firmware battery-check sequence the moment a new cell is detected. It checks internal resistance, open-circuit voltage, and charge state before clearing the fault flag. A freshly shipped Li-ion cell typically arrives at 30–50% state of charge, which is below the threshold the module expects for a healthy battery. Put the vehicle on a full charge cycle — either via engine run or external charger — and allow at least two hours before the module re-evaluates. The fault flag clears automatically once the BMS confirms acceptable voltage and charge acceptance.

Emergency system not activating hazard lights or door unlock during a power loss event

If the emergency functions fail to trigger during a main power loss, the most likely cause is that the replacement battery was installed but never completed a full charge cycle, so the module has not yet accepted it as the active supply source. The module holds the previous runtime map in memory and will not switch over to an unvalidated cell. Fully charge the battery through a complete engine cycle, then simulate a low-voltage event using a diagnostic tool or disconnect the main battery briefly to confirm module switchover. The emergency supply output rail should read between 7.0V and 8.4V during activation.