🔧 Accord - Battery Replacement

You’ll remove the old 12V battery from the engine bay and install a new one, then reconnect the cables in the correct order. This restores reliable starting and prevents low-voltage electrical issues.

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

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⚠️ Safety & Precautions

• ⚠️ Wear eye protection and gloves; battery acid is corrosive.
• ⚠️ Keep sparks/flames away; batteries can vent hydrogen gas.
• ⚠️ Remove metal jewelry (rings/watches) to prevent shorts.
• ⚠️ Disconnect negative (-) first and reconnect it last to reduce short-circuit risk.
• ⚠️ Have your radio/security code available (battery disconnect may reset audio settings).

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 1/4" drive ratchet
• 6" extension (1/4" drive)
• 10mm combination wrench
• Torque wrench (inch-pound or small ft-lb)
• Battery terminal puller (specialty)
• Battery terminal cleaning brush
• Small flathead screwdriver
• Shop towels
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• 12V battery (BCI Group Size 51R) - Qty: 1
• Battery terminal anti-corrosion washers - Qty: 2
• Battery terminal protectant spray or dielectric grease - Qty: 1

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📋 Before You Begin

• 🅿️ Park on level ground, turn the ignition OFF, remove the key, and open the hood.
• 🧾 Write down any saved settings you care about (clock, radio presets).
• 🧤 Identify terminals: positive (+) is usually under a red cover; negative (-) is typically bare/black.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Access the battery and inspect the area

• Locate the battery in the engine bay.
• Use a shop towel to wipe off dirt so nothing falls into the tray.
• If the positive terminal has a cover, open it by hand or with a small flathead screwdriver.

Step 2: Disconnect the negative (-) cable first

• Use a 10mm socket with a ratchet to loosen the negative terminal clamp nut.
• Wiggle the clamp up and off the terminal.
• If it’s stuck, use a battery terminal puller (specialty) (this tool gently presses the clamp off without damaging the battery post).
• Tuck the negative cable end aside so it can’t spring back and touch the terminal.
• Torque to 5 N·m (44 in-lbs / 3.6 ft-lbs) on reassembly.

Step 3: Disconnect the positive (+) cable

• Use a 10mm socket with a ratchet to loosen the positive terminal clamp nut.
• Lift the clamp straight up and off the terminal.
• Move the positive cable aside so it cannot contact metal parts.
• Torque to 5 N·m (44 in-lbs / 3.6 ft-lbs) on reassembly.

Step 4: Remove the battery hold-down

• Use a 10mm socket, ratchet, and extension to remove the hold-down nuts/bolts (J-hooks/brace).
• Lift the hold-down bracket off and set it aside.
• Torque to 9.8 N·m (87 in-lbs / 7.2 ft-lbs) on reassembly.

Step 5: Remove the old battery

• Lift the battery straight up and out using the built-in handle (if equipped).
• Set it on the ground upright (don’t tip it).
• It’s heavier than it looks—lift with legs.

Step 6: Clean the tray and terminals

• Inspect the battery tray for corrosion (white/blue crust).
• Use shop towels to clean the tray area.
• Use a battery terminal cleaning brush to clean the inside of both cable clamps until the metal looks bright.

Step 7: Install the new battery

• Place the new Group Size 51R battery into the tray in the same orientation as the old one.
• Reinstall the hold-down bracket using the 10mm socket, ratchet, and extension.
• Torque to 9.8 N·m (87 in-lbs / 7.2 ft-lbs).

Step 8: Reconnect the cables (positive first, negative last)

• Install anti-corrosion washers (if using) onto the terminals.
• Reconnect the positive (+) clamp first and tighten using a 10mm socket.
• Torque to 5 N·m (44 in-lbs / 3.6 ft-lbs).
• Reconnect the negative (-) clamp last and tighten using a 10mm socket.
• Torque to 5 N·m (44 in-lbs / 3.6 ft-lbs).
• Apply battery terminal protectant spray or dielectric grease lightly to slow future corrosion.

Step 9: Final checks

• Confirm the battery is clamped down and cannot move.
• Make sure the terminal clamps are fully seated and not crooked.
• Close the positive terminal cover (if equipped).

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✅ After Repair

• ✅ Start the engine and verify it cranks strongly.
• ✅ Reset the clock and radio presets as needed.
• ✅ Power window auto function may need initialization: fully raise the driver window, then keep holding the switch UP for 2 seconds.
• ✅ Let the engine idle for a few minutes with all accessories OFF to help it stabilize after battery power loss.

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💰 DIY vs Shop Cost

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

DIY Cost: $120-$220 (parts only)

You Save: $60-$130 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.