What kind of battery is in a Subaru Forester?
The Forester generally uses a 12-volt lead-acid battery for the vehicle’s starting and electrical systems; however, models with start-stop or mild-hybrid features often use an AGM (Absorbent Glass Mat) battery to cope with higher electrical demands. Exact type and size vary by year and market, so always check the battery label or the owner's manual for your specific model.
In practice, the Forester’s 12-volt battery sits beneath the hood as the main power source for starting the engine and running accessories. In hybrids or variants with energy-recovery systems, a separate high-voltage setup exists, while the 12-volt battery remains essential for the car’s everyday operations. This article outlines what to expect and how to identify the right replacement.
Battery types across Forester generations
Subaru’s Forester has used two main 12-volt configurations across its lifecycle. One is the conventional flooded lead-acid battery used in most non-hybrid models; the other is an AGM battery used in models with stop-start or mild-hybrid features to better cope with frequent cycling and higher electrical demands.
Conventional flooded lead-acid batteries (most models)
Most non-hybrid Forester models rely on a standard 12-volt, flooded lead-acid battery. It’s typically maintenance-free in modern cars, but it remains the baseline option that balances cost and performance.
Below is a quick overview of the common characteristics you’ll see with this type in the Forester:
- Maintenance: Often maintenance-free, though older or base models may require occasional fluid checks if not sealed.
- Charging: Compatible with standard alternator charging; typical daily driving suffices to keep it charged.
- Replacement factors: Group size, CCA (cold-cranking amps), and reserve capacity vary by year; check the label or manual.
The conventional battery remains the default in many markets for Forester models without start-stop or hybrid tech.
AGM batteries (start-stop or hybrid variants)
For Foresters equipped with start-stop or mild-hybrid systems, manufacturers often opt for an AGM (Absorbent Glass Mat) 12-volt battery. AGM batteries tolerate frequent cycling better and resist vibration, which helps with more demanding electrical draw.
Key points about AGM in Foresters:
- Better cycle life and vibration resistance, suited to frequent engine-off scenarios.
- Maintenance-free and sealed, with typically higher initial cost but longer life under heavy use.
- Important: if your model has start-stop or e-Boxer mild-hybrid features, the replacement must be AGM or a battery specified by Subaru to ensure compatibility with the vehicle’s charging system.
In markets where the Forester has hybridization, AGM is more common; verify with your VIN or owner’s manual for the exact requirement.
How to identify the correct replacement battery for your Forester
Choosing the right battery starts with confirming the exact specification for your model year and market. Use the following guidelines to match the replacement.
- Check the battery group size printed on the battery label and compare it to your Forester’s specification, which can vary by year and market (common possibilities include several sizes depending on configuration).
- Match the cold-cranking amps (CCA) rating to the engine and climate expectations; higher CCA is beneficial in cold climates or for vehicles with higher electrical demand.
- Determine whether your model requires an AGM battery (for start-stop or hybrid-equipped variants) or a conventional flooded battery; using the wrong type can affect charging and performance.
- Note the terminal configuration and orientation to ensure cables reach securely without modifications.
Always verify with the owner’s manual, the battery label, or a dealership/service technician to confirm the correct type and size for your vehicle.
Maintenance and replacement tips
Keeping your Forester’s battery in good condition reduces the risk of starting problems and electrical glitches. Here are practical tips to manage replacement and maintenance.
- Inspect terminals for corrosion and clean with a mild solution if needed; ensure clamps are tight to prevent voltage loss.
- Expect replacement intervals around 3-5 years in typical climates; severe heat or cold or frequent short trips can shorten life.
- When replacing, recycle the old battery properly through a parts store or service center; many offer a core credit.
With proper care and a correctly matched specification, your Forester’s 12-volt battery should provide reliable starts and steady electrical performance.
Summary
The Subaru Forester primarily uses a 12-volt lead-acid battery. In most non-hybrid variants, this is the conventional flooded type; in models with start-stop or mild-hybrid features, it is typically an AGM battery. Always verify the exact group size, CCA rating, and battery type from the owner’s manual or the battery label, and replace only with a matched specification to maintain reliability and compatibility.
Does a Subaru require a special battery?
Whether you drive an SUV like the Subaru Forester, Outback, Ascent or Crosstrek, or have a car like the Subaru Legacy or Impreza, the battery you're looking for is here, either in-store or online. Does your Subaru need a special battery to run? Not at all.
What type of battery is used in a Subaru Forester?
AGM type battery
Working for an auto parts store, a 2020 subaru forester would take a group size 35 battery and requires the top tier AGM type battery.
How much does a new battery for a Subaru Forester cost?
A Subaru Forester battery replacement costs approximately $180 to $350, but can range from about $45 to $250 for the part alone, depending on the battery's quality, size, and power requirements. The total cost will vary based on where you get the battery (auto parts store, dealership, etc.) and whether you pay for installation or do it yourself.
Factors influencing the cost
- Battery type and quality: Standard batteries are cheaper, while premium or AGM (Absorbed Glass Mat) batteries for cars with start-stop technology will be more expensive.
- Labor costs: Professional installation adds to the total price. The cost of labor varies by shop and location.
- Model and year: Older Forester models may have lower costs, while newer models could be higher.
- Battery warranty: Some batteries come with longer warranties, which can affect the initial price.
Where to get your battery replaced
- Dealership: Often uses manufacturer-recommended parts and may have higher labor rates, but offers specialized knowledge.
- Auto parts store: Offers a wide selection of batteries at competitive prices and may provide free installation with the purchase of a new battery.
- Independent mechanic: Can be a good option for finding a balance between price and quality.
How do I know if my battery is AGM or EFB?
You are looking for AGM or EFB printed on the label. Failing that / next – write down the name / number of the battery – examples being Bosch S6 or Varta E39, this will help if you cannot see AGM / EFB as sometimes it is stated in the front label which may not be easy to see unless the battery is out of the vehicle.
