How to Replace the Car Battery in Your 2020 Subaru

Replacing the battery in your 2020 Subaru is a straightforward DIY job that can save you time and money. This guide walks you through the entire 2020 Subaru battery replacement process, from safety prep to reconnecting terminals. You’ll learn the exact steps, tools needed, and common mistakes to avoid.

If your 2020 Subaru won’t turn over on a cold morning, a weak battery is often the reason. Replacing the 2020 Subaru battery is one of the simplest maintenance tasks you can do yourself. This guide covers everything you need to know, from gathering the right tools to safely installing the new unit.

Many owners assume they need a dealership for a battery swap. In reality, a few basic tools and about half an hour are all it takes. You’ll save money and gain confidence in maintaining your vehicle. Let’s walk through the process step by step.

Key Takeaways

• DIY Replacement: You can swap the battery on a 2020 Subaru in under 30 minutes with basic tools.
• Safety First: Always wear gloves and safety glasses, and disconnect the negative terminal first to prevent shorts.
• Correct Battery Size: Using the right group size and cold cranking amps ensures reliable starts in all seasons.
• Clean Terminals: Remove corrosion from battery cables and tray before installing the new unit.
• Reset Systems: After replacement, you may need to reset the clock, radio presets, and power windows.
• Regular Maintenance: Check battery health annually and clean terminals to extend battery life.

Why Battery Replacement Matters for Your 2020 Subaru

The battery powers your starter, lights, and infotainment system. Over time, battery terminals collect corrosion, and the charge weakens. A failing battery can leave you stranded. Regular replacement keeps your Subaru reliable.

Signs Your Battery Is Failing

• Slow cranking when you turn the key.
• Dim headlights or interior lights.
• A check engine or battery warning light on the dash.
• Swollen or bloated battery case.
• Needing frequent jump-starts.

Quick Tip: If your Subaru takes longer than usual to start, don’t wait—test the battery. A simple voltage check can prevent a sudden failure.

How Long Does a 2020 Subaru Battery Last?

Most car batteries last three to five years. Extreme heat or cold shortens that battery life. If you live in a harsh climate, inspect your unit every year. Subaru models like the Outback and Forester often see heavy use, so staying ahead of wear is smart.

Tools and Safety Gear You’ll Need

Gathering the right equipment makes the job smooth and safe. Here is what you need before you begin.

• Combination wrench set (8mm, 10mm, and 13mm are common).
• Socket wrench with a deep socket.
• Safety glasses and chemical-resistant gloves.
• Battery cleaning solution or a mixture of baking soda and water.
• Wire brush or battery terminal cleaner.
• Dielectric grease or terminal protectant spray.
• A new battery that matches your Subaru’s specifications.

Common Mistake: Never use a wrench that is too big for the terminal nut. It can slip and damage the clamp or your hand.

Expert Insight: Subaru batteries are located under the hood, but some trims have a plastic cover. Check your owner’s manual for the exact location and battery group size. Having a memory saver device is also a good idea to preserve radio codes and ECU settings.

Step-by-Step Guide to Removing the Old Battery

Follow these steps carefully to remove the old car battery safely. Work on a level surface and keep metal objects away from the terminals.

1. Park on a Level Surface and Turn Off the Engine. Engage the parking brake and let the engine cool completely.
2. Locate the Battery and Remove the Cover. In most 2020 Subarus, the battery sits on the left side of the engine bay. Remove the plastic cover if equipped.
3. Disconnect the Negative Terminal First. Use your wrench to loosen the nut on the black cable clamp. Twist and lift the clamp off the terminal. Secure the cable away from the battery.
4. Disconnect the Positive Terminal. Repeat the process for the red cable. Always positive last to avoid accidental shorts.
5. Remove the Battery Hold-Down and Tray. Loosen the clamp or bracket that secures the battery. Lift the old unit straight out and place it on a stable surface.

Quick Tip: Apply a thin layer of dielectric grease to the terminals after cleaning. This protects against future corrosion and makes future replacements easier.

What to Do with the Old Battery

Car batteries contain lead and sulfuric acid. Do not throw them in the trash. Take the old unit to an auto parts store, recycling center, or dealership. Many places accept used batteries for a small core charge refund.

Installing the New Battery Correctly

Once the old battery is out, you can install the new 2020 Subaru battery. Take your time to ensure a solid connection.

1. Place the New Battery in the Tray. Make sure the positive and negative terminals match the cable locations. The battery should sit snugly in the tray.
2. Secure the Battery Hold-Down. Tighten the bracket or clamp firmly. The battery should not move when you push it gently.
3. Connect the Positive Terminal First. Place the red clamp over the positive post. Tighten the nut snugly but do not overtighten.
4. Connect the Negative Terminal. Attach the black clamp to the negative post and tighten the nut.
5. Apply Terminal Protector. Spray a protectant or apply grease to both terminals. This guards against battery terminal corrosion.

Before you close the hood, double-check that both connections are tight. A loose terminal can cause electrical issues or a no-start condition.

Choosing the Right Replacement Battery

Not all batteries are the same. Check your owner’s manual for the correct group size, cold cranking amps (CCA), and reserve capacity. The table below compares two common options for your Subaru battery.

Feature	Standard Lead-Acid	AGM (Absorbed Glass Mat)
Price Range	Lower cost	Higher cost
Lifespan	3–5 years	4–6 years
Vibration Resistance	Good	Excellent
Maintenance	Sealed, no watering	Sealed, no watering

If your Subaru has a start-stop system or heavy audio upgrades, an AGM battery is a great choice. For standard driving, a quality lead-acid unit works well. Always match the cold cranking amps to your climate.

Testing and Maintenance Tips for Long Battery Life

Your new 2020 Subaru battery will last longer with simple care. A few habits make a big difference.

• Check Voltage Regularly: A fully charged battery should read 12.6 volts or higher with the engine off. Use a digital multimeter for an accurate battery tester reading.
• Clean Terminals Every Few Months: Mix a tablespoon of baking soda with a cup of water. Use an old toothbrush to scrub the terminals and cable ends. Rinse with a damp cloth and dry thoroughly.
• Avoid Short Trips: Frequent short drives don’t give the alternator enough time to fully recharge the battery. Take a longer drive occasionally to top it off.
• Turn Off Accessories Before Shutdown: Lights, rear defroster, and high-draw audio systems should be off before you turn the key to the off position.

Expert Insight: Have a professional battery tester perform a load test annually. This checks the battery’s actual capacity, not just its resting voltage. A battery that passes a voltage test can still fail under load.

Common Mistakes to Avoid When Replacing a 2020 Subaru Battery

Even simple tasks have pitfalls. Steering clear of these errors keeps you safe and prevents damage.

• Disconnecting the Positive Terminal First: This can cause a short if the wrench touches metal. Always negative first, positive last.
• Using the Wrong Battery Size: A battery that is too small or too large can damage the tray and electrical system. Verify the group size before you buy.
• Forgetting to Reset Systems: After a car battery replacement, you may need to reset the clock, radio presets, and power window auto-up/down settings.
• Leaving Lights or Accessories On: This drains the new battery before you even drive away. Do a quick visual check before closing the hood.
• Ignoring Corrosion on the Cables: If the cable ends are corroded, the new battery won’t get a clean connection. Clean or replace damaged cables.

Quick Tip: Keep a memory saver device plugged into the OBD-II port during the swap. It preserves all your electronic settings, so you don’t have to reprogram everything.

Once the new unit is in and connected, start the engine. The dashboard lights should illuminate normally, and the engine should crank quickly. Listen for any unusual clicks or grinding, which could indicate a loose connection or a faulty starter. If everything sounds smooth, you have successfully completed a 2020 Subaru battery replacement.

Final Thoughts on Your 2020 Subaru Battery Replacement

Swapping the battery on a 2020 Subaru is a task anyone can handle with the right guidance. You now know how to spot a failing battery, gather the proper tools, remove the old unit safely, and install a new one with confidence. Regular maintenance like cleaning terminals and testing voltage will extend your battery life and keep your Subaru ready to go.

Take a moment to dispose of the old battery responsibly and note the date of installation. Mark your calendar for a check-up in three years, or sooner if you notice any warning signs. With this knowledge, you are better equipped to care for your vehicle and avoid unexpected breakdowns. Get under the hood, give your 2020 Subaru battery the attention it deserves, and enjoy the peace of mind that comes with a job well done.

Frequently Asked Questions

How long does a 2020 Subaru battery last?

Most 2020 Subaru battery units last between three and five years. Extreme temperatures, frequent short trips, and heavy accessory use can shorten that lifespan. Regular testing helps you catch a weak battery before it fails.

Can I use any battery for my 2020 Subaru?

No, you must match the group size, terminal placement, and cold cranking amps specified in your owner’s manual. Using the wrong car battery replacement unit can lead to poor fitment, electrical issues, or damage to the charging system. Always double-check the specifications before purchasing.

What size battery does a 2020 Subaru need?

The majority of 2020 Subaru models use a group size 35 or 34 battery. Some trims with higher electrical demands may require a different size. Refer to your owner’s manual or the label on the existing battery to confirm the correct group size and CCA rating.

How do I reset my Subaru after replacing the battery?

After a 2020 Subaru battery replacement, you may need to reset the clock, radio presets, and power window auto-up/down functions. For the windows, hold the switch to fully raise the glass, then pull it to fully lower, and release. The system will relearn the auto-stop position.

Is it hard to replace the battery in a 2020 Subaru?

It is a straightforward DIY job that takes about 20 to 30 minutes. You only need a few basic tools and should follow the safety steps of disconnecting the negative terminal first. If you feel unsure, a quick visit to a parts store can also get the job done for you.

How much does it cost to replace a 2020 Subaru battery?

The cost of a 2020 Subaru battery replacement ranges from $150 to $300 for the part and labor if you go to a shop. Doing it yourself saves you the labor charge. The price varies based on battery type, brand, and cold cranking amps required for your model.