What happens when you replace a Subaru battery

Replacing a Subaru battery means removing the old battery from under your hood and installing a new one in its place. The job takes 30 minutes to an hour at a dealership or independent shop, or you can do it yourself if you have basic tools. When the battery dies or loses its charge, your Subaru won't start, and you'll need a replacement before you can drive again.

Subaru batteries typically last three to five years depending on climate, driving habits, and how often you use electrical features like heated seats or the infotainment system. Cold weather drains batteries faster, so owners in northern climates often replace them sooner. A battery that won't hold a charge, makes clicking sounds when you turn the key, or leaves your lights dim is usually at the end of its life.

Key Takeaways

  • Subaru batteries come in different sizes depending on your model year and engine type, so you need to know which one fits before you buy.
  • You can replace the battery yourself with basic hand tools, or have a dealership or independent shop do it for $100 to $300 including labor.
  • After installation, your Subaru may need a short drive to relearn certain settings, and you should check that all electrical features work as expected.
  • Keeping your battery terminals clean and your electrical system in good condition extends battery life and prevents premature failure.

Finding the right battery size for your Subaru

Subaru uses different battery sizes across its model lineup. The most common sizes are Group 35, Group 51R, and Group 48. Your owner's manual lists the correct size for your specific year and model, or you can find it on a sticker under your hood near the battery itself. Taking a photo of that sticker before you shop makes it straightforward to match at any retailer.

If you don't have your manual, call your Subaru dealership with your vehicle identification number (VIN) — it's on your registration and dashboard — and they'll tell you the exact battery you need. Many auto parts stores also look up the right battery by VIN when you visit or call. Buying the wrong size won't fit in the battery tray or may not have enough power for your engine, so this step matters.

Cold cranking amps (CCA) is the number that tells you how much starting power the battery has. Subaru batteries typically range from 400 to 600 CCA depending on engine size. You can match or exceed the original CCA rating, but don't go below it — your engine needs that power to turn over in cold weather.

Replacing the battery yourself

You'll need a wrench or socket set (usually 8mm or 10mm), a battery terminal puller (optional but helpful), and the new battery. Disconnect the negative terminal first — it's usually marked with a minus sign or black cable — by loosening the bolt and sliding the cable off. Then disconnect the positive terminal the same way. This order matters because disconnecting negative first prevents electrical sparks.

Remove any battery hold-down bracket or strap by unbolting it, then lift the old battery straight up and out. It's heavy, so use both hands. Set the new battery in the tray, reattach the hold-down bracket, then reconnect the positive terminal first and the negative terminal second. Tighten both connections firmly — a loose terminal causes starting problems and electrical gremlins.

After installation, start your Subaru and let it run for a few minutes. Your dashboard may show warning lights or ask you to confirm settings — this is normal as the car relearns its electrical baseline. Drive for 10 to 15 minutes at normal speeds so the alternator can charge the new battery fully. Check that your headlights, wipers, heated seats, and other electrical features work as they should.

Having a shop replace your battery

Subaru dealerships charge between $150 and $300 for battery replacement including labor, depending on your model and location. Independent repair shops and chain auto parts stores typically charge $100 to $200. Many retailers offer battery installation for free or a small fee if you buy the battery from them, so ask about that when you price shop.

When you take your Subaru in, bring your keys and be prepared to wait 30 to 60 minutes. The shop will disconnect the old battery, remove it, install the new one, and test the electrical system to make sure everything works. Some shops will also clean your battery terminals and check your alternator while they're at it — ask if that's included or what it costs.

If you're having the work done at a dealership, they'll use a Subaru-approved battery and can reprogram any settings that need it after installation. Independent shops use aftermarket batteries that are usually less expensive but still reliable. Either way, most batteries come with a three-year or five-year warranty, so keep your receipt in case you need to return it.

Battery cost and warranty information

Subaru replacement batteries range from $80 to $200 depending on size and brand. OEM (original equipment manufacturer) Subaru batteries cost more than aftermarket brands like Interstate, Optima, or DieHard, but they're may provide to fit and perform as the manufacturer intended. Aftermarket batteries often have the same or better specs at a lower price.

Most batteries come with a three-year full replacement warranty and a five-year prorated warranty. Full replacement means the maker will replace it free if it fails during year one, two, or three. Prorated warranty means they'll credit you a percentage of the cost if it fails after year three, based on how long you've owned it. Keep your receipt and warranty paperwork in your glove box.

Extending your battery's lifespan

Clean battery terminals every six months or whenever you notice white, blue, or green corrosion buildup. Disconnect the negative terminal, mix baking soda and water into a paste, scrub the terminals and cable ends with an old toothbrush, rinse with clean water, and reconnect. Corrosion blocks the electrical connection and forces your battery to work harder than it should.

Avoid leaving your Subaru parked for weeks without driving it — the battery slowly drains even when the engine is off. If you know you won't drive for more than two weeks, disconnect the negative terminal to stop the drain. In winter, park in a garage if you can, because cold temperatures reduce battery power by up to 50 percent. Keep your alternator in good condition by having it tested during routine service — a failing alternator won't recharge your battery properly.

What to do if your battery dies while driving

If your battery fails completely, your Subaru will lose power steering, power brakes, and all electrical systems. You'll coast to a stop and won't be able to restart. Call roadside information or a tow truck to take you to a shop — don't try to drive on a dead battery because you'll lose steering and braking control.

If you're stranded and have jumper cables and another vehicle nearby, you can jump-start your Subaru to get it running long enough to reach a shop. Connect the positive cable to the positive terminal on your battery, then to the positive terminal on the other car's battery. Connect the negative cable to the negative terminal on the other car's battery, then to an unpainted metal surface on your engine block — not directly to your battery. Start the other car, wait two minutes, then start your Subaru. Drive directly to a shop and don't turn off the engine until you get there.

Frequently Asked Questions

How do I know if my Subaru battery is dying?

Your engine cranks slowly or clicks repeatedly when you turn the key, your headlights are noticeably dim, or the battery warning light appears on your dashboard. If your Subaru won't start at all but the lights work, the battery is likely dead. A battery that's three to five years old and showing any of these signs is probably near the end of its life.

Can I replace my Subaru battery in the winter?

Yes, but cold weather makes the job harder because batteries lose power in freezing temperatures. Work quickly, keep the new battery warm before installation, and let your Subaru run for several minutes after you install it so the alternator can charge it fully. If it's below zero, consider having a shop do it instead.

Will replacing my battery erase my radio presets or other settings?

Disconnecting the battery may clear some settings like radio presets, clock, and seat position memory on newer models. Your Subaru will ask you to confirm or reset these when you restart it. Write down your radio station frequencies before you start if you want to avoid reprogramming them.

What should I do with my old battery?

Don't throw it in the trash — car batteries contain lead and acid that are hazardous waste. Most auto parts stores and dealerships will take your old battery for free when you buy a new one, or charge a small core fee if you don't. Some recycling centers also accept car batteries.

Is it cheaper to buy a battery online and install it myself?

Online batteries are often $20 to $50 cheaper than retail stores, but you pay for shipping and may wait several days for delivery. If you install it yourself, you save $100 to $200 in labor. If you're comfortable with basic tools and have the time, buying online and doing it yourself saves the most money. If you'd rather have it done quickly and correctly, a shop's convenience may be worth the extra cost.