🔧 CX-5 - 12V Battery Replacement

Your CX-5’s 12V battery sits in the engine bay and powers starting plus all electronics. Replacing it is mostly a “remove and reinstall” job, but polarity order (negative first/last) matters to avoid electrical damage.

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

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⚠️ Safety & Precautions

• ⚠️ Turn ignition OFF, remove the key, and keep it away from the vehicle.
• ⚠️ Disconnect the negative (-) terminal first and reconnect it last.
• ⚠️ Do not let a tool touch the battery positive (+) and any metal body part at the same time.
• ⚠️ Battery acid is corrosive—wear gloves and safety glasses.
• ✅ Battery disconnect is recommended/required for this job.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 12mm socket
• 1/4" ratchet
• 3" extension for ratchet
• Torque wrench (5-25 Nm range)
• Battery terminal puller (specialty)
• Wire brush
• Battery terminal cleaning tool
• Shop towels
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• 12V battery (match the Group Size and CCA shown on your old battery label) - Qty: 1
• Battery terminal anti-corrosion spray or grease - Qty: 1
• Battery terminal felt washers - Qty: 2

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📋 Before You Begin

• Park on level ground, shift to neutral, and set the parking brake.
• Open the hood and let the engine bay cool if it’s hot.
• Plan for basic resets after replacement (clock, radio presets, and power window auto-up).
• Tip: Take a quick photo of the terminals first.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Locate the battery and identify terminals

• Find the battery in the engine bay.
• Identify negative (-) (usually black cable, marked “-”) and positive (+) (often under a red cover, marked “+”).

Step 2: Disconnect the negative (-) terminal

• Use a 10mm socket with a 1/4" ratchet to loosen the negative terminal clamp nut.
• Twist the clamp gently and lift it off the post.
• If it’s stuck, use a battery terminal puller (specialty) (a small tool that presses the clamp off without prying).
• Torque to 6-8 Nm (53-71 in-lbs) when reinstalling later.

Step 3: Disconnect the positive (+) terminal

• Use a 10mm socket to loosen the positive terminal clamp nut.
• Lift the clamp off and position it so it cannot spring back onto the battery.
• Torque to 6-8 Nm (53-71 in-lbs) when reinstalling later.

Step 4: Remove the battery hold-down

• Use a 12mm socket, ratchet, and 3" extension to remove the hold-down nuts/bolts.
• Remove the hold-down bracket and set it aside.
• Torque to 9-12 Nm (80-106 in-lbs) when reinstalling later.

Step 5: Remove the old battery

• Lift the battery straight up and out (it’s heavy—keep your back straight).
• Set it on the ground upright (do not tip it).

Step 6: Clean the tray and terminals

• Wipe the battery tray with shop towels.
• Clean the inside of both cable clamps using a battery terminal cleaning tool or wire brush.
• Install battery terminal felt washers if you’re using them.

Step 7: Install the new battery

• Place the new battery into the tray with the terminals oriented the same way as the old one.
• Reinstall the hold-down bracket using the 12mm socket.
• Torque to 9-12 Nm (80-106 in-lbs).

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

• Reconnect the positive (+) clamp first using the 10mm socket.
• Torque to 6-8 Nm (53-71 in-lbs).
• Reconnect the negative (-) clamp last using the 10mm socket.
• Torque to 6-8 Nm (53-71 in-lbs).
• Apply a light coat of battery terminal anti-corrosion spray or grease.
• Tip: Clamps should not rotate by hand.

Step 9: Final check

• Make sure the battery is secure and does not move.
• Verify tools are removed from the engine bay.

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✅ After Repair

• Start the engine and confirm normal cranking.
• Set the clock and re-save radio presets if needed.
• Power window re-learn (if auto-up/down stops working): with the engine running, use the driver window switch to fully lower, then fully raise and hold the switch up for 2-3 seconds.
• Check for battery warning lights; if one stays on, recheck terminal tightness and cleanliness.

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💰 DIY vs Shop Cost

Shop Cost: $180-$350 (parts + labor)

DIY Cost: $120-$260 (parts only)

You Save: $60-$150 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.