🔧 Forester - Battery Replacement

Replacing the 12V battery is a straightforward job: you’ll remove the old battery, clean the connections, and install the new one. Doing it the right way prevents electrical damage and helps avoid starting/charging problems.

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

---

⚠️ Safety & Precautions

• ⚠️ Keep the key fob away from the car and ignition OFF while working.
• ⚠️ Do not let a tool touch both the battery terminal and metal body parts.
• ⚠️ Always disconnect the negative (-) terminal first and reconnect it last.
• ⚠️ Batteries can vent gas and acid—wear gloves and safety glasses.
• ⚠️ If your battery has a vent tube (a small hose), reconnect it to the new battery.

---

🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 1/4" ratchet
• 6" extension
• 10mm combination wrench
• Battery terminal brush
• Small wire brush
• Shop rags
• Nitrile gloves
• Safety glasses
• OBD-II memory saver (specialty)
• 12V jump pack (optional)

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• 12V battery (Group 35, 550+ CCA) - Qty: 1
• Battery terminal anti-corrosion pads - Qty: 2
• Battery terminal protector spray - Qty: 1
• Dielectric grease - Qty: 1
• Battery hold-down J-bolts and nuts - Qty: 1 set

---

📋 Before You Begin

• Park on level ground, shift to P, and set the parking brake.
• Open the hood and keep it securely propped.
• If you want to keep radio presets and clock, connect an OBD-II memory saver (specialty). (A memory saver is a small device that supplies low power while the battery is removed.)
• Make sure you know your radio settings/presets if you’re not using a memory saver.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Locate the battery and identify terminals

• Find the battery in the engine bay.
• Look for + (positive) and - (negative) markings.
• If there’s a vent tube (small hose going into the side of the battery), note where it connects.

Step 2: Disconnect the negative (-) terminal

• Use a 10mm socket with a 1/4" ratchet to loosen the negative terminal pinch bolt.
• Twist and lift the negative cable end straight up off the battery post.
• Tuck the cable to the side so it can’t spring back onto the post. Negative off first prevents sparks.
• Torque to 5 Nm (44 in-lbs) on reassembly.

Step 3: Disconnect the positive (+) terminal

• Use a 10mm socket with a 1/4" ratchet to loosen the positive terminal pinch bolt.
• Remove the positive cable end from the battery post.
• Cover the positive cable end with a shop rag so it can’t touch metal.
• Torque to 5 Nm (44 in-lbs) on reassembly.

Step 4: Remove the battery hold-down bracket

• Use a 10mm socket with a 6" extension to remove the two hold-down nuts at the top of the J-bolts.
• Lift off the hold-down bar and set it aside.
• Torque to 7.5 Nm (66 in-lbs) on reassembly.

Step 5: Remove the old battery

• Wearing nitrile gloves, lift the battery straight up and out.
• Batteries are heavy—keep it close to your body and lift with your legs.
• If equipped, pull the vent tube out of the battery carefully (don’t tear it).

Step 6: Clean the tray and cable ends

• Use shop rags to wipe debris from the battery tray.
• Use a battery terminal brush to clean the inside of the cable ends until shiny.
• Use a small wire brush to clean corrosion from the hold-down hardware if needed.
• Install battery terminal anti-corrosion pads onto the posts (if using them).

Step 7: Install the new battery

• Place the new battery into the tray in the same orientation as the old one.
• If your battery uses a vent tube, connect it to the correct vent port on the new battery.
• Reinstall the hold-down bar and start both nuts by hand.
• Use a 10mm socket to tighten evenly side-to-side.
• Torque to 7.5 Nm (66 in-lbs).

Step 8: Reconnect the positive (+) terminal first

• Place the positive cable end fully down on the positive post.
• Use a 10mm socket to tighten the pinch bolt.
• Torque to 5 Nm (44 in-lbs).
• Apply a thin film of dielectric grease to the outside of the connection, then apply battery terminal protector spray.

Step 9: Reconnect the negative (-) terminal last

• Place the negative cable end fully down on the negative post.
• Use a 10mm socket to tighten the pinch bolt.
• Torque to 5 Nm (44 in-lbs).
• Apply battery terminal protector spray.

---

✅ After Repair

• Start your Forester and confirm it cranks normally and no warning lights stay on.
• Let it idle for 5-10 minutes with all accessories OFF so the ECU can relearn idle. Normal idle may vary at first.
• Reset the clock and reprogram radio presets if needed.
• If one-touch windows don’t work, reinitialize by holding the window switch fully down, then fully up for a few seconds.
• Check that the battery is secure and the cables don’t rotate on the posts.

---

💰 DIY vs Shop Cost

Shop Cost: $220-$450 (parts + labor)

DIY Cost: $140-$280 (parts only)

You Save: $80-$170 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.

---

🎯 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.