Chevrolet Impala 12V Battery Size and Replacement
The short answer
No single battery fits every Chevy Impala. The correct replacement depends on the model year, which tells you the generation, and on the engine. The reliable way to choose is to match three things from the battery your car came with: the group size, the cold cranking amps rating and the battery type. You can find these on the label of the factory battery or in the owner's manual for your model year.
This guide does not list group sizes by year. Verified fitment data for each Impala generation and engine was not available for this article, so confirm the exact size for your car before you buy.
Why the model year and engine matter
The Impala name has covered several distinct generations. They include the classic rear-wheel-drive models, the front-wheel-drive revival that began with the 2000 model year, the 2006–2013 generation, the 2014–2016 Impala Limited sold alongside the newer car, and the 2014–2020 final generation. These cars differ in body design, engine bay layout and electrical demands. A battery that suits one generation may not fit the tray or cable reach of another. Within a single generation, different engines can also call for different capacity ratings.
If your Impala has been modified, or if a previous owner installed a non-original battery, check the owner's manual or a fitment lookup by year and engine. Do not assume the battery now in the car is correct.
The specifications to match
Group size: a standardized code for the battery's physical dimensions and terminal layout. It determines whether the battery sits in the tray, clamps down properly and lets the cables reach. Terminal position: some group sizes come in mirrored versions with the positive and negative posts on opposite sides, often marked with an R suffix. The wrong orientation can leave cables too short or put them under strain. Cold cranking amps (CCA): a measure of how much current the battery can deliver to start the engine in cold conditions. Meet or exceed the original rating. Reserve capacity: how long the battery can run essential electrical loads if the charging system stops working. Higher is generally better, as long as the battery still fits. Battery type: conventional flooded lead-acid or AGM (absorbent glass mat), a sealed design that handles frequent deep discharges better. If your Impala came with an AGM battery, replace it with an AGM battery.
Before you replace it
A car that is slow to start does not always have a bad battery. Corroded or loose terminals, a failing alternator or a parasitic drain can cause similar symptoms. Many parts stores and repair shops can test the battery and charging system before you commit to a replacement.
Confirm where the battery sits in your Impala before starting. The location and access vary by generation, so check the owner's manual for your model year.
General replacement steps
Turn off the ignition and all accessories, and wear eye protection and gloves. Disconnect the negative cable first, then the positive cable. Remove the hold-down clamp and lift the old battery out carefully, since batteries are heavy and contain acid. Clean any corrosion from the cable ends and the tray. Set the new battery in the same orientation, secure the hold-down and connect the positive cable first, then the negative. Check that both clamps are tight and the battery does not move in the tray.
Disconnecting the battery can reset radio presets, clock settings and other stored preferences. Some newer vehicles also have battery monitoring or electrical management features that may need attention after a battery change. Check the owner's manual or ask a dealer whether this applies to your Impala's model year.
Return the old battery to a retailer or recycling point. Lead-acid batteries should not go in household waste, and many sellers take old units back when you buy a replacement.
Choosing your next step
Write down your Impala's model year and engine, then read the group size, CCA rating and type from the current battery label or the owner's manual. Use those details to compare replacement batteries. If the label is missing or the specifications don't agree, a fitment lookup by year and engine, or a quick check at a parts counter, will settle it before you buy.