Mini Coopers come in multiple powertrains, so the battery size depends on the model. In general, modern Minis use a 12-volt auxiliary battery around 60 Ah, while electric and hybrid variants carry larger high-voltage packs: about 32.6 kWh gross (28.9 kWh usable) for the EV, and roughly 9–11 kWh usable for plug-in hybrids. For precise numbers, check your specific model and year.
12-volt auxiliary battery in modern Mini Coopers
The standard 12‑volt battery powers starting systems, lights and electronics. In most current Minis, this is a lead‑acid or AGM battery sized around 60 Ah. The 12‑V battery is typically located in the engine bay, with replacement intervals around 4–5 years under normal use. Some models with Start‑Stop systems use AGM designs. Always verify with the owner’s manual or dealer for your exact spec.
Typical 12V battery sizes you might see
Below is a practical summary of common 12V battery capacities used in modern Mini Cooper variants. This is a general guide; exact fit depends on year and trim.
- 60 Ah (typical for many current petrol, diesel and mild-hybrid Minis)
- 50–60 Ah (seen in some earlier or lighter-spec trims)
- AGM batteries (common on Start-Stop-equipped models)
In practice, most modern Minis use a 60 Ah 12‑V battery. If your car uses a nonstandard size, it will be listed in the service manual or stamped on the battery itself.
High-voltage battery sizes in Mini Cooper variants
In addition to the 12‑V system, electric and plug-in hybrid Minis carry larger high‑voltage battery packs. These packs determine electric driving capability and charging behavior. The numbers vary by model year and market, but the following reflect typical configurations in recent generations.
- MINI Cooper SE (electric): about 32.6 kWh gross lithium‑ion pack, around 28.9 kWh usable.
- MINI Countryman Plug‑In Hybrid (Cooper S E ALL4): high‑voltage pack typically in the single-digit to low-double-digit kWh usable range (roughly 9–11 kWh usable, depending on generation).
- Earlier plug‑in hybrids used similar compact high‑voltage packs; newer models may differ slightly by year/market.
For exact numbers, refer to the vehicle’s specification sheet or the VIN-based build data from BMW/MINI or a dealer.
Checking the exact battery size for your Mini
Because battery size can differ by market, trim, and production year, confirm via these sources:
- Owner’s manual specification page
- Under-hood battery label (shows capacity and group size)
- VIN-based build data from the dealer or MINI official services
- Official MINI technical specification pages for your model year
Knowing the exact spec helps with replacements, charging equipment compatibility, and warranty considerations.
Why battery size matters
The 12‑V battery affects starting reliability and electrical systems, while the high‑voltage pack determines electric range and charging behavior in EVs and PHEVs. Always use the correct replacement type (AGM vs flooded for 12V) and ensure safe handling of high‑voltage components in EVs.
Summary
In modern Minis, the 12‑V auxiliary battery is typically around 60 Ah, with AGM variants common on Start‑Stop models. The MINI Electric (Cooper SE) uses a 32.6 kWh gross high‑voltage battery (about 28.9 kWh usable). Plug‑in hybrids carry high‑voltage packs in the single-digit to low-double-digit kWh usable range (roughly 9–11 kWh usable). For precise figures, check the exact model/year documentation or your vehicle’s VIN build data.