Which battery is best for a Subaru Forester?
For most Subaru Forester models, the best overall choice is a Group 35, 12-volt battery with at least 600 CCA; an AGM battery is worth considering in very cold climates or when you run heavy electrical loads.
The Forester spans many model years and trims, so the exact size and chemistry can vary. Below is guidance to help you pick the right battery based on year, climate, and usage, plus practical buying tips and things to check before you buy.
Know your Forester's requirements
Most Forester versions use a standard 12V automotive battery, with Group Size 35 being the most common fit for recent model years. Always verify the correct group size and electrical specs by checking the existing battery label or the owner's manual.
Common sizes and fitment notes
Forester models typically use Group 35 as the standard size. Some older models or region-specific variants may use Group 24F or other sizes, so confirming the exact group size before purchasing is essential.
- Group Size 35: The most common fit for many Forester models; typical CCA in the 540–700 range; usually a flooded lead-acid battery with a maintenance-free design.
- Group Size 24F: Occasional alternative for older trims or specific markets; verify fitment and terminal orientation before buying.
- Group Size 34R/others: Rare in Forester but possible in some markets; always confirm with the manual or current battery label.
In short, always confirm the exact group size and spec required for your particular Forester by checking the manual or the stamped label on the battery you remove.
Battery chemistry and performance
Choose between a standard flooded lead-acid battery and a modern AGM (absorbed glass mat) battery. Each has advantages depending on climate and electrical demand.
AGM vs Flooded: when to choose
Flooded lead-acid batteries are typically the most affordable and sufficient for everyday use in moderate climates. AGM batteries offer better cold-start performance, higher resistance to vibration, and longer life, especially when you have cold winters or a lot of electrical draw from accessories. AGM is more expensive but can be worth it in harsh conditions or if you frequently take short trips that don’t allow a flooded battery to fully recharge.
- Flooded lead-acid: Best value, widely available; suitable for plain driving in mild climates; lower upfront cost.
- AGM: Higher performance in cold weather and with high electrical loads; longer life; higher upfront cost but may save money over time.
Bottom line: If you live in a cold climate or run extra electronics, an AGM is worth the premium; otherwise, a high-quality flooded battery that meets Subaru's specs is a solid choice.
Practical buying tips
Use the following checklist to ensure you pick the right battery and install it correctly.
Step-by-step buying checklist
- Check Group Size: Confirm the exact size required for your Forester (e.g., Group 35, 24F) from the owner's manual or the battery label.
- Check CCA and RC: Choose a battery with cold-cranking amps that meet or exceed Subaru's recommended minimum (typically around 550–700 CCA) and a reserve capacity of 90–120 minutes or more.
- Choose chemistry: Flooded vs AGM based on climate and electrical usage; consider AGM for cold climates or heavy loads.
- Warranty: Look for at least 2–4 years of warranty; longer warranties can indicate higher quality or longer life.
- Installation: If you’re not comfortable, have a professional install to ensure proper connection and disposal of the old battery.
- Compatibility: Ensure terminal orientation and cable fitment match your Forester’s battery tray and terminal posts.
Following these steps helps ensure you select a battery that fits your Forester’s specs and your local driving conditions.
Summary
For most Subaru Forester owners, a Group 35, 12-volt battery is the practical default. If you live in very cold areas or carry heavy electrical loads, an AGM battery with higher CCA and reserve capacity is worth considering. Always verify the exact group size and specs for your year and market, prioritize a reputable brand, and weigh price versus warranty and life expectancy. Regular maintenance and proper recycling of old batteries also help keep your Forester starting reliably year-round.
