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Battery Group Numbers
| Group | Capacity (Ah) | CCA | Dimensions | Typical Cars |
|---|---|---|---|---|
| 063 | 44–45Ah | 420–440 | 207 × 175 × 175mm | Small city cars, superminis |
| 027 | 60–65Ah | 600–680 | 242 × 175 × 190mm | Medium hatchbacks, saloons |
| 096 | 70–76Ah | 640–760 | 278 × 175 × 190mm | Larger cars, medium diesels |
| 110 | 80Ah | 720 | 315 × 175 × 175mm | Large diesels, premium cars |
| 019 | 95Ah | 850 | 353 × 175 × 190mm | Large SUVs, premium vehicles |
Recommended Batteries
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Source: UK (BBMS) type numbers cross-referenced against GS Yuasa, VARTA and Exide published data. Capacity and CCA vary by brand and range within the same type number — use the type number for physical fit and terminal layout only. Last verified August 2026.
What Do the Numbers Mean?
The type number itself — 063, 027, 096 and so on — is a UK (BBMS) code that tells you the case size, terminal layout and polarity. It does not fix the capacity or the cold cranking amps. Type 027, for example, is sold as a conventional battery, an EFB and an AGM, all in the same 242 × 175 × 190 mm box, at anything from 60 to 65 Ah and 600 to 680 A depending on the range. Use the type number to check it will physically fit and the terminals are the right way round; use your handbook or a registration lookup for the capacity, CCA and technology your car actually needs.
These are not BCI group sizes. BCI is the North American system, and the numbers clash: BCI Group 27 is roughly 306 × 173 × 225 mm and about 90 Ah, which is a much bigger battery than UK type 027. If you are buying from a US listing, check the physical dimensions rather than the number.
Ah (Amp-hours) measures total energy storage — how long the battery can supply power before going flat. Higher Ah = more reserve capacity.
CCA (Cold Cranking Amps) measures the battery’s ability to start the engine in cold weather. Higher CCA = better cold starts. This is especially important in the UK where winter mornings regularly hit -5°C to -10°C.
How to Find Your Battery Size
The easiest method is to use our battery finder — select your car and we’ll tell you the exact group, type, and capacity. Alternatively, check the label on your existing battery or your vehicle handbook.
Frequently Asked Questions
Can I fit a higher Ah battery?
Only with care. It has to physically fit the tray with the terminals the right way round, and you must keep the same technology — flooded, EFB or AGM. On a car with a battery management system, which includes most start-stop vehicles, the charging strategy is set to the registered battery’s capacity and type, so fitting a different battery without registering it causes chronic under- or over-charging and early failure. Check your handbook, and have the new battery registered if your car requires it.
Does CCA matter in the UK?
Absolutely. UK winter temperatures regularly drop below freezing. Low CCA batteries struggle to turn the engine over on cold mornings. Always match or exceed the original CCA rating.
Are all batteries with the same group number interchangeable?
They should be physically interchangeable, but always verify the terminal position (left/right positive) and type (standard, EFB, AGM) for your vehicle.
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How we check fitment for this guide
We cross-reference fitment figures against manufacturer specifications and OE-supplier catalogue data where available, and matched to the standard codes that actually govern fit — battery type/group sizes, wiper lengths and fitting types, bulb fitment codes, tyre size markings, and oil specifications. We work by make, model, year, engine, and build date, because a single model can take different parts across its life. Where the right part depends on your exact vehicle, we tell you to confirm by registration or VIN. More on our method →