🔧 Accent - 12V 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. Doing it carefully prevents sparks, damaged electronics, and loose connections that cause no-start problems.

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

---

⚠️ Safety & Precautions

• 🔋 Batteries can spark and vent gas; keep flames and cigarettes away.
• 🧪 Battery acid is corrosive; wear gloves and safety glasses.
• ⚡ Always disconnect the negative (-) terminal first and reconnect it last to reduce short-circuit risk.
• 🛠️ Do not let a metal tool touch the battery positive and any metal body part at the same time.
• 🔌 Battery disconnect is required for this repair.

---

🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 10mm ratchet
• 6-inch extension for 3/8" ratchet
• 12mm socket
• Torque wrench (5-30 Nm range)
• Battery terminal brush
• Fender cover
• Nitrile gloves
• Safety glasses

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• 12V car battery (BCI Group 121R) - Qty: 1
• Battery terminal anti-corrosion pads - Qty: 2
• Battery terminal protectant spray or dielectric grease - Qty: 1

---

📋 Before You Begin

• Park on level ground, turn the ignition off, remove the key, and open the hood.
• Wait 2-3 minutes before disconnecting the battery so modules go to sleep.
• Set a fender cover over the paint to prevent scratches.
• Tip: Take a quick photo of the terminals first.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Assumption: Typical hardware for your Accent uses 10mm terminal nuts and a 12mm hold-down fastener; layouts can vary slightly by battery brand.

Step 1: Disconnect the negative (-) battery cable

• Use a 10mm socket and 10mm ratchet to loosen the nut on the negative (-) terminal clamp.
• Wiggle and lift the clamp straight up off the battery post.
• Tuck the cable to the side so it cannot spring back onto the post.
• Torque to 5-6 Nm (44-53 in-lbs) on reassembly.
• Tip: Negative is usually black.

Step 2: Disconnect the positive (+) battery cable

• Use a 10mm socket and 10mm ratchet to loosen the nut on the positive (+) terminal clamp.
• Remove the clamp from the post and move it aside so it cannot touch metal.
• Torque to 5-6 Nm (44-53 in-lbs) on reassembly.
• Tip: Positive often has a red cover.

Step 3: Remove the battery hold-down

• Locate the battery hold-down bracket at the base of the battery.
• Use a 12mm socket, 10mm ratchet, and 6-inch extension for 3/8" ratchet as needed to remove the hold-down bolt(s).
• Lift the hold-down bracket out and set it aside.
• Torque to 18-22 Nm (13-16 ft-lbs) on reassembly.

Step 4: Remove the old battery

• Lift the battery straight up and out. Keep it upright.
• Place it on the ground in a safe spot.
• If there’s white/blue buildup on terminals, that’s corrosion.

Step 5: Clean the terminals and prepare the new battery

• Use a battery terminal brush to clean the inside of both cable clamps until shiny metal is visible.
• Install battery terminal anti-corrosion pads on the new battery posts.
• Apply a light coat of battery terminal protectant spray or dielectric grease after the cables are tightened.
• Tip: Clean metal = best electrical contact.

Step 6: Install the new battery and secure it

• Set the new battery into the tray with the terminals oriented the same way as the old one.
• Reinstall the hold-down bracket using a 12mm socket and 10mm ratchet.
• Finish with a torque wrench (5-30 Nm range): Torque to 18-22 Nm (13-16 ft-lbs).

Step 7: Reconnect the positive (+) cable, then the negative (-) cable

• Install the positive (+) clamp first and tighten using a 10mm socket and 10mm ratchet.
• Use a torque wrench (5-30 Nm range): Torque to 5-6 Nm (44-53 in-lbs).
• Install the negative (-) clamp last and tighten using a 10mm socket and 10mm ratchet.
• Use a torque wrench (5-30 Nm range): Torque to 5-6 Nm (44-53 in-lbs).
• Spray or apply a thin coat of battery terminal protectant to both connections.
• Tip: Tight is good; crushed clamps are not.

---

✅ After Repair

• Start the engine and verify the battery light turns off after starting.
• Check that both clamps do not rotate by hand.
• Reset the clock and any radio presets if they were lost.
• Let the engine idle for 5 minutes with accessories off to help the idle relearn.
• Recycle the old battery (most parts stores take it and may refund a core charge).

---

💰 DIY vs Shop Cost

Shop Cost: $220-$420 (parts + labor)

DIY Cost: $140-$260 (parts only)

You Save: $80-$160 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.