🔧 Impreza - Battery Replacement

You’ll remove the old 12V battery and install a new one with clean, tight connections. A weak or failing battery can cause slow cranking, warning lights, or random electrical glitches.

Difficulty Level: Beginner | Estimated Time: 0.5-1.0 hours

Assumption: Torque specs below are best-effort common Subaru values.

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⚠️ Safety & Precautions

• ⚠️ Keep keys out of the car and ignition OFF while working.
• ⚠️ Wear eye protection and gloves; battery acid is corrosive.
• ⚠️ Never short the battery terminals with a tool.
• ⚠️ Disconnect negative (-) first and reconnect negative (-) last.
• ⚠️ If the battery was recently charged/driven, let it sit a few minutes before disconnecting.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 3/8" drive ratchet
• 3" extension for ratchet
• 12mm socket
• Battery terminal puller (specialty)
• Battery post/terminal cleaning brush
• Torque wrench (5-30 Nm range)
• Battery carrying strap
• Shop rags
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• 12V battery (Group Size 35) - Qty: 1
• Battery terminal anti-corrosion felt washers - Qty: 2
• Battery terminal protectant spray - Qty: 1
• Dielectric grease - Qty: 1

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📋 Before You Begin

• Park on level ground, shift to P, and set the parking brake.
• Open the hood and locate the battery (front of engine bay).
• If you have radio presets you care about, write them down (some settings may reset).
• Identify the terminals: negative (-) is usually black; positive (+) usually has a red cover.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Power down and access the battery

• Turn everything OFF and remove the key/fob from the cabin.
• Use safety glasses and nitrile gloves before touching the terminals.

Step 2: Disconnect the negative (-) battery terminal

• Use a 10mm socket with a ratchet to loosen the negative terminal clamp nut.
• Twist the clamp gently and lift it off the battery post.
• If it’s stuck, use a battery terminal puller (specialty) (this tool pushes the clamp off without prying).
• Tuck the negative cable aside so it cannot spring back and touch the terminal.
• Torque on install: Torque to 5 Nm (44 in-lbs)

Step 3: Disconnect the positive (+) battery terminal

• Flip open the positive terminal cover (if equipped).
• Use a 10mm socket with a ratchet to loosen the positive terminal clamp nut.
• Lift the clamp off the battery post and position it so it can’t touch metal.
• Torque on install: Torque to 5 Nm (44 in-lbs)

Step 4: Remove the battery hold-down bracket

• Use a 10mm socket (and 3" extension if needed) to remove the hold-down nuts from the J-bolts.
• Some versions use 12mm socket hardware—use whichever fits snugly.
• Lift off the hold-down bracket and set it aside.
• Torque on install: Torque to 18 Nm (13 ft-lbs)

Step 5: Remove the old battery

• Use a battery carrying strap and lift the battery straight up and out.
• Keep it upright to avoid any leakage.

Step 6: Clean the terminals and tray

• Use a battery post/terminal cleaning brush to clean the inside of both cable clamps until shiny.
• Wipe the battery tray area with shop rags.
• Clean metal makes strong starting power.

Step 7: Install the new battery

• Place the new battery into the tray in the same orientation as the old one (terminals match the cables).
• Install battery terminal anti-corrosion felt washers on the posts.
• Reinstall the hold-down bracket and tighten using a 10mm socket or 12mm socket.
• Finish tightening with a torque wrench: Torque to 18 Nm (13 ft-lbs)

Step 8: Reconnect terminals (positive first, negative last)

• Install the positive (+) terminal first. Use a 10mm socket to tighten, then torque wrench: Torque to 5 Nm (44 in-lbs)
• Apply a thin film of dielectric grease around the outside of the connection (not between clamp and post).
• Install the negative (-) terminal last. Tighten with a 10mm socket, then torque wrench: Torque to 5 Nm (44 in-lbs)
• Spray both terminals with battery terminal protectant spray.

Step 9: Quick check for secure fit

• Try to rotate each terminal by hand—there should be no movement.
• Confirm the hold-down bracket is tight and the battery can’t slide.

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✅ After Repair

• Start the engine and confirm normal cranking and idle.
• Reset the clock and radio presets if needed.
• If power windows lost “auto” function: hold the window switch fully down for 2 seconds, then fully up for 2 seconds.
• Check for warning lights; if any stay on, shut off and recheck terminal tightness.

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💰 DIY vs Shop Cost

Shop Cost: $220-$380 (parts + labor)

DIY Cost: $150-$280 (parts only)

You Save: $70-$100 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.5-1.0 hours.

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🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.