Battery Group Numbers
| Group | Capacity (Ah) | CCA | Dimensions | Typical Cars |
|---|---|---|---|---|
| 063 | 40Ah | 340 | 207 × 175 × 175mm | Small city cars, superminis |
| 027 | 60Ah | 540 | 242 × 175 × 190mm | Medium hatchbacks, saloons |
| 096 | 72Ah | 640 | 278 × 175 × 190mm | Larger cars, medium diesels |
| 110 | 80Ah | 720 | 315 × 175 × 190mm | Large diesels, premium cars |
| 019 | 95Ah | 850 | 353 × 175 × 190mm | Large SUVs, premium vehicles |
Recommended Batteries for Car Sizes & Group Numbers Explained
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What Do the Numbers Mean?
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?
Yes, as long as it physically fits the battery tray. A higher Ah battery provides more reserve capacity and won’t harm anything. The alternator will charge whatever size you fit.
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.
Recommended Products
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 →