In most Subarus with internal-combustion engines, you need a standard 12-volt lead-acid battery (AGM is common). For Subaru's hybrids and electric models, the vehicle uses a high-voltage traction battery rather than a conventional 12V battery for propulsion. The exact type depends on the model and year.
Gasoline-powered Subarus: 12-volt batteries
The following points cover the typical 12-volt battery used in Subaru models that run on gasoline or mild-hybrid systems.
- Battery type: Most newer Subarus use a 12-volt lead-acid battery, with many models installed as an AGM (absorbed glass mat) type for better resistance to vibration and longer life. Some very early or budget trims may still use flooded lead-acid batteries.
- Group size: The correct group size is dictated by the vehicle’s design. Always verify the exact size from the owner’s manual, the battery label, or Subaru’s parts fiche. Common sizes seen in Subarus include Group 35, Group 48, or Group 51R, depending on model.
- Performance specs: Choose a replacement that meets or exceeds the OEM ratings for cold-cranking amps (CCA) and reserve capacity (RC). CCA can range roughly from 350 to 700 A depending on the battery size, while RC typically falls in the 90–140 minute range for common sizes.
- Maintenance and installation: AGM batteries are sealed and maintenance-free, but if you’re replacing a flooded type, you’ll need to monitor electrolyte levels and terminals. Ensure correct terminal orientation, clean connections, and torque specifications when installing.
- Warranty and replacement timing: Expect a factory or dealer-backed warranty that commonly spans multiple years, with aftermarket options offering their own warranties. Lifespan under normal use is typically several years, but can vary with climate and driving conditions.
In practice, the best approach is to replace with an OEM-recommended battery or a high-quality aftermarket battery that matches the vehicle’s group size and CCA rating as specified in the owner’s manual or parts catalog.
How to identify the right battery size
To confirm the correct battery size for your Subaru, check the current battery’s side label, consult the owner’s manual, or contact a Subaru dealer with your VIN. Many parts catalogs and retailers will also list compatible group sizes once you provide the model-year and trim.
Subarus with hybrid or electric powertrains
For hybrids and fully electric Subarus, the focus shifts from a small 12-volt starting battery to a high-voltage traction battery pack that powers the electric motors. The exact chemistry, capacity, and configuration vary by model and year.
- Traction battery type and capacity: The high-voltage battery is a large traction pack, typically lithium-ion or a similar chemistry, with capacity that varies by model (and is generally designed to deliver propulsion energy over many miles). Exact figures depend on the model and market.
- Service and safety: High-voltage systems require specialized training, tools, and safety procedures. Do not attempt to service, disconnect, or jump-start high-voltage components yourself. Only certified technicians should handle these systems.
- 12-volt companion battery: Even in hybrids and EVs, a standard 12-volt battery remains for electronics and accessories. Replacement for this battery follows the same guidance as gasoline models, but service for the high-voltage pack is handled separately.
- Warranty and maintenance: The traction battery and related high-voltage components are covered under separate warranties tied to the hybrid/electric system. Check the vehicle’s warranty booklet or talk to a dealer for exact terms.
In short, when dealing with Subaru’s hybrid or electric models, you aren’t shopping for a simple 12-volt battery for propulsion—the primary concern is the high-voltage traction battery. Always follow dealer guidance for inspection, service, and replacement.
Safety reminders for high-voltage systems
High-voltage batteries require proper safety precautions. If you suspect a problem with the traction battery or high-voltage wiring, contact a Subaru-certified technician. Never open high-voltage enclosures, attempt to bypass safety interlocks, or perform DIY repairs on these systems.
Summary
For most Subaru gasoline-powered models, use a standard 12-volt lead-acid battery, preferably AGM, in the group size and with the CCA/RC ratings specified by Subaru. Hybrid and electric Subarus use high-voltage traction batteries for propulsion, with the 12-volt battery still supporting electronics; service and replacement for the high-voltage pack are handled by dealers. Always verify exact specifications in the owner’s manual, on the current battery, or with a Subaru dealer, and prioritize safety when dealing with high-voltage systems.