🔧 Accord - Battery Replacement

Replacing the 12V battery restores reliable starting power and prevents random electrical glitches (slow crank, warning lights, dead battery). On your Accord, it’s a straightforward swap in the engine bay, but the connection order matters.

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

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⚠️ Safety & Precautions

• ⚠️ Keep sparks/flames away from the battery area.
• ⚠️ Wear eye protection—batteries can vent corrosive gas.
• ⚠️ Always disconnect the negative (–) terminal first and reconnect it last.
• ⚠️ Do not let your tool touch the positive (+) terminal and metal body parts at the same time.
• ⚠️ Battery is heavy—lift with two hands and keep it upright.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 1/4" ratchet
• 6" extension (1/4")
• 10mm combination wrench
• Battery terminal puller (specialty)
• Battery post/terminal cleaning brush
• Torque wrench (in-lb)
• Nitrile gloves
• Safety glasses
• Fender cover
• Memory saver (specialty)

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• 12V battery (Group Size 51R) - Qty: 1
• Battery terminal anti-corrosion pads - Qty: 2
• Battery terminal protectant spray - Qty: 1

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📋 Before You Begin

• 🅿️ Park on level ground, shift to Park, and shut the engine off.
• 🔑 Remove the key/fob from the car and keep it away from the vehicle.
• 🧤 Put on nitrile gloves and safety glasses.
• 🔌 Optional: Use a memory saver (specialty) (a small device that keeps settings powered through the OBD port or 12V outlet) if you want to reduce lost settings.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Open access and identify terminals

• Open the hood and locate the battery at the front of the engine bay.
• Identify the negative (–) terminal (usually black cable) and positive (+) terminal (usually under a red cover).
• Place a fender cover over the edge to protect paint.

Step 2: Disconnect the negative (–) terminal first

• Use a 10mm socket with 1/4" ratchet to loosen the negative terminal nut.
• Wiggle and lift the clamp off the battery post.
• If it’s stuck, use a battery terminal puller (specialty) to lift it straight up. Don’t pry hard with a screwdriver.
• Tuck the negative cable to the side so it cannot spring back onto the post.

Step 3: Disconnect the positive (+) terminal

• Flip up/open the positive terminal cover if equipped.
• Use a 10mm socket to loosen the positive terminal nut, then lift the clamp off.
• Move the positive cable aside so it can’t touch the battery post.

Step 4: Remove the battery hold-down

• Use a 10mm socket with a 6" extension (1/4") to remove the hold-down nuts/bolts at the base of the hold-down bracket.
• Lift off the hold-down bracket and set it aside.

Step 5: Remove the old battery

• Lift the battery straight up and out using two hands. Keep it upright.
• Check the battery tray for corrosion or wetness.

Step 6: Clean the terminals and prep anti-corrosion pads

• Use a battery post/terminal cleaning brush to clean the inside of both cable clamps and the battery posts (if reusing posts on a new battery, lightly clean anyway).
• Install battery terminal anti-corrosion pads onto the posts (one per post).

Step 7: Install the new battery (Group 51R) and secure it

• Set the new 12V battery (Group Size 51R) into the tray with the posts oriented the same as the original.
• Reinstall the hold-down bracket and start the nuts/bolts by hand.
• Use a 10mm socket to tighten the hold-down fasteners evenly.
• Finish with a torque wrench (in-lb): Torque to 9 Nm (80 in-lbs).

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

• Install the positive (+) clamp first.
• Use a 10mm socket to tighten: Torque to 5 Nm (44 in-lbs).
• Install the negative (–) clamp last.
• Use a 10mm socket to tighten: Torque to 5 Nm (44 in-lbs).
• Spray both terminals with battery terminal protectant spray.

Step 9: Final check

• Gently try to rotate each terminal by hand—there should be no movement.
• Make sure the hold-down is tight and the battery cannot slide.

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✅ After Repair

• 🔍 Start the engine and confirm the starter cranks strongly.
• 🕒 Reset the clock and any saved settings that were lost.
• 🪟 If the auto-up/down window feature stops working: with the engine on, use the driver window switch to fully lower the window, then fully raise it and hold the switch up for 2 seconds.
• 🛠️ If idle is rough after reconnecting: let the engine warm up fully, then idle in Park with all accessories off for about 5 minutes. Don’t touch the gas pedal.

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💰 DIY vs Shop Cost

Shop Cost: $250-$450 (parts + labor)

DIY Cost: $160-$250 (parts only)

You Save: $90-$200 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.