Hyundai Sonata 12V battery size and replacement
The short answer
The right replacement 12V battery for a 2011 Sonata matches the group size, terminal layout and cold cranking amps listed for your specific car, either on the original-equipment battery label or in the owner's manual. The material used for this article does not include a confirmed group size or rating for the 2011 model, so no specific figure is given here. Treat any single number you see quoted without reference to engine and market with caution, and confirm it using the steps below before buying.
Three conditions can change the answer. The first is powertrain: the 2011 Sonata was sold with a 2.4-litre four-cylinder, a 2.0-litre turbocharged four-cylinder and a hybrid version, and battery specifications should be checked for the exact version rather than assumed to be shared. The second is market, because vehicles built for different regions can be specified with different batteries. The third is history: a previous owner or shop may already have fitted a battery that differs from the original, so the battery currently in the car is not proof of the correct size.
Terms you will see on battery listings
Group size: an industry code describing a battery's case dimensions and terminal positions. Matching it means the battery fits the tray and hold-down and the cables reach the posts. Cold cranking amps (CCA): a rating of how much current the battery can deliver to start an engine in cold conditions. A replacement should meet or exceed the specified figure. Terminal orientation: which side the positive and negative posts sit on. A mirror-image layout can leave cables too short or touching the wrong post. Reserve capacity: how long a fully charged battery can supply a steady load if the charging system stops working.
How to confirm the correct battery for your Sonata
Check the owner's manual specifications section for the battery type and rating listed for your engine. Read the label on the installed battery for group size and CCA, then confirm it matches the manual in case it has been replaced before. Use a parts retailer or dealer lookup with your vehicle identification number (VIN), which ties the result to your exact build rather than just the model year. Confirm the trim and engine on the lookup screen match your car, especially if you own the hybrid or the turbocharged version. Compare the physical dimensions and post layout of any proposed replacement against the old battery before installation.
If you own the Sonata Hybrid
The hybrid carries a high-voltage traction battery that drives the electric motor, and it is separate from the 12V battery covered here. The supplied material does not confirm where the 2011 Sonata Hybrid's 12V battery is located or which type it uses, so check the owner's manual or a dealer before buying. Do not work on any orange high-voltage cabling or components.
Before you replace the battery
Test the old battery and charging system first, because a weak alternator or a parasitic drain can make a healthy battery appear faulty. Match group size and terminal layout, and choose a CCA rating at or above the specification. Make sure the hold-down clamp secures the new battery firmly so it cannot shift. Expect that disconnecting the battery may reset stored settings such as radio presets and the clock; the manual will indicate whether anything else needs resetting. Return the old battery to a retailer or recycling point rather than discarding it.
What could not be confirmed here
The supplied information did not include the 2011 Sonata's battery group size, CCA rating, reserve capacity, battery location for each version, prices or warranty terms. These details should come from the owner's manual, a VIN-based parts lookup or a Hyundai dealer for your specific engine and market.