What happens when you replace a Subaru battery

A Subaru battery replacement removes your old battery and installs a new one in its place. The job takes 30 minutes to an hour at a dealership or independent shop, though you can do it yourself if you have basic tools and feel comfortable working under the hood. The new battery will have the same voltage and size as your original, so it fits the same way and connects to the same terminals.

Before the replacement, a technician will disconnect the negative terminal first, then the positive terminal, to prevent electrical shock. They'll remove the battery hold-down bracket, lift out the old battery, and set the new one in place. The terminals get reconnected in reverse order — positive first, then negative — and the hold-down bracket goes back on. Your vehicle's computer may need a few minutes to relearn some settings after the battery is installed.

Key Takeaways

  • Subaru batteries typically last three to five years, and replacement costs between $100 and $300 depending on the model year and battery type.
  • You can replace the battery yourself with basic hand tools if you disconnect the negative terminal first and follow the same order when reconnecting.
  • A Subaru dealership will charge more than an independent shop, but both will warranty the new battery for at least one year.
  • After installation, your vehicle may take a few minutes to relearn idle settings and radio presets, which is normal.

When your Subaru needs a new battery

Most Subaru batteries fail between three and five years of use, though this varies by climate and driving habits. Cold weather drains battery power faster and shortens lifespan, so vehicles in northern regions often need replacement sooner. You'll notice warning signs like slow engine cranking, dim headlights, or a clicking sound when you turn the key.

If your battery is more than three years old and you're seeing these signs, a battery test at any shop will tell you whether replacement is necessary. Some shops offer this test for free. If the battery still has charge but is aging, you can wait — but keep jumper cables in your vehicle in case it fails unexpectedly.

Doing the replacement yourself versus using a shop

A DIY replacement requires a wrench set (usually 8mm and 10mm), a socket set, and about 30 minutes. You'll need to locate the battery under the hood, disconnect the negative terminal first by loosening the bolt on the cable clamp, then disconnect the positive terminal the same way. Remove the hold-down bracket, lift out the old battery — they weigh 30 to 50 pounds — and set the new one in place. Reconnect positive first, then negative, and reinstall the bracket.

The main risk of DIY work is connecting the terminals in the wrong order, which can damage your vehicle's electrical system. If you're uncertain, a shop replacement costs $150 to $300 total and removes that risk. A Subaru dealership will charge more than an independent mechanic, but both will stand behind the battery with a warranty.

Battery costs and warranty coverage

Subaru battery prices range from $100 to $300 depending on your model year and engine size. Newer models and turbocharged engines often need higher-capacity batteries, which cost more. An independent shop typically charges $50 to $100 for labor, while a dealership charges $100 to $150 for the same work.

All new batteries come with a manufacturer warranty covering defects, usually for three years or 36,000 miles. Some shops offer an additional warranty on labor for one year. If the battery fails during the warranty period, the shop will replace it at no cost. Keep your receipt — you'll need it to claim the warranty.

What to expect after the battery is installed

Your Subaru's computer controls many functions that depend on battery power, including idle speed, fuel mixture, and radio station presets. When the battery is disconnected, these settings reset. After the new battery is installed and the terminals are reconnected, your vehicle may idle roughly for a few minutes or a few miles while the computer relearns these settings. This is normal and requires no action on your part.

Your radio presets, clock, and any custom settings will be erased and need to be reprogrammed. Some vehicles also lose their seat and mirror position memory. Write down your radio stations before you have the work done if you want to avoid reprogramming them later.

Choosing the right battery type for your Subaru

Most Subaru vehicles use a standard lead-acid battery, which is the least expensive option and works well in most climates. Some newer models offer an AGM (absorbed glass mat) battery option, which lasts longer and handles cold weather better, but costs $50 to $100 more. If you live in a very cold climate or drive in extreme conditions, an AGM battery may be worth the extra cost.

Your owner's manual or the battery label under the hood will show the correct battery group size and cold-cranking amps (CCA) for your vehicle. Always match these specifications when buying a replacement. A shop can look this up for you if you don't have the manual.

Where to buy a Subaru battery

You can purchase a battery from a Subaru dealership, an independent mechanic, an auto parts store like AutoZone or O'Reilly, or online retailers like Amazon. Dealerships stock batteries matched to your exact model, but charge the highest price. Auto parts stores carry multiple brands and price points, and many will install the battery for free or a small fee if you buy it there. Online retailers often have lower prices, but you'll need to arrange installation separately.

If you buy from an auto parts store, bring your vehicle identification number (VIN) or your old battery so the staff can confirm the correct size and type. Most stores will also test your current battery for free to confirm it needs replacement before you buy a new one.

Frequently Asked Questions

Can I drive my Subaru if the battery is weak but not completely dead?

Yes, but only short distances in daylight. A weak battery may start the engine but could fail while you're driving, leaving you stranded. If your battery is more than three years old and showing signs of weakness, plan the replacement soon rather than waiting for a failure.

Will replacing the battery erase my vehicle's computer codes or check engine light?

No. Disconnecting the battery does not clear diagnostic codes stored in your vehicle's computer. If your check engine light is on, it will still be on after the battery replacement. You'll need a separate diagnostic scan to find out what triggered it.

How do I know if my battery is original or has been replaced before?

Look at the date code on the battery label. It's usually a letter and number — the letter represents the month (A for January, B for February, and so on) and the number is the year. If the date is more than three years ago, the battery is aging and may fail soon.

What should I do if my Subaru won't start after the new battery is installed?

First, check that both terminal clamps are tight and making full contact with the battery posts. Corrosion or loose connections are the most common cause of no-start after a replacement. If the connections are tight and the vehicle still won't start, the shop should retest the battery and check the alternator and starter.

Is it worth paying extra for a battery with a longer warranty?

Most standard batteries come with a three-year warranty, which covers the typical lifespan. A longer warranty usually costs $20 to $40 more and may be worth it if you plan to keep the vehicle for five years or longer. If you trade in or sell your vehicle within three years, the standard warranty is usually enough.