Ford Focus Mk3 Battery: Specs, Fitment & Common Faults

Confirmed OEM battery references for the Mk3, and why stop-start disabling itself doesn't automatically mean the battery has failed.

Generation covered: this guide is for the third-generation Focus, built 2011–2018 (commonly the 2014–2018 registered examples still in daily use). The newer Mk4 Focus (2018–) uses different part numbers throughout — check your V5C logbook or VIN if you're unsure which generation you have.

Illustration for editorial purposes

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The Part Everyone Blames First, Not Always Correctly

On the Ford Focus Mk3, no single component gets blamed for a no-start more than the battery, and often that blame is justified, making it a sensible first check. But it isn't the whole story every time, so it's worth confirming before spending on a replacement that might not actually fix anything.

Before you buy: battery size, capacity and type (standard vs AGM/EFB for stop-start systems) vary by trim and engine. Always confirm against your VIN before ordering.

OEM Part Numbers & Sizes

Accuracy note: battery specification on the Mk3 Focus depends heavily on engine, trim, and whether the car has Ford's stop-start system — always confirm your existing battery's size and Ah rating (printed on the case) before ordering, rather than relying on part number alone.

Common OEM cross-reference	Ford 000915105DA, 13502901, 282915105 (widely used group across several petrol and diesel variants)
Typical case dimensions	Length 207–317mm, width 175mm, height 175–190mm (varies by spec — measure your existing battery)
Stop-start equipped cars	Require an AGM or EFB battery, not a standard flooded-cell replacement — fitting the wrong type can damage the stop-start system

Because Ford fitted several different battery capacities across the Mk3's production run — depending on engine, trim, and whether stop-start is fitted — the safest way to order the right one is by the Ah rating and case size printed on your current battery, cross-checked against your VIN, rather than assuming a single part number covers every car.

Ford Focus Mk3 Battery: What It Does

Whenever the Ford Focus Mk3's engine isn't turning, the 12V battery is what keeps electrical systems running and handles the next start. That workload is much higher on stop-start versions, given how often the engine switches off and restarts, which is exactly why they call for an AGM or EFB battery rather than a standard type.

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Ford Focus Mk3 Battery: Warning Signs, DIY Difficulty & Aftermarket Advice

These are the same regardless of make or model — see our full Battery Guide for warning signs to watch for, confirming fitment against your VIN, and matching the right technology (standard, EFB, AGM) when buying aftermarket.

More Ford Battery

The same part, covered across other Ford models.