🔧 Optima - Battery Replacement

Replacing the 12V battery restores reliable starting and prevents low-voltage glitches (slow crank, warning lights, random electrical issues). The job is straightforward: remove the hold-down, swap the battery, and reconnect the terminals in the correct order.

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

---

⚠️ Safety & Precautions

• ⚠️ Turn the ignition OFF and keep the key fob at least 10 feet away from your Optima.
• ⚠️ Always disconnect the negative (-) battery cable first and reconnect it last to reduce short-circuit risk.
• ⚠️ Do not let a wrench touch the body metal and the battery positive (+) terminal at the same time.
• ⚠️ Battery acid is corrosive; wear gloves and safety glasses.
• ⚠️ Battery disconnect is not strictly required, but it will reset some memories (clock, radio presets).

---

🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 12mm socket
• 3/8" ratchet
• 6" socket extension
• Torque wrench (5-30 Nm range)
• Battery terminal brush (specialty)
• Protective gloves
• Safety glasses

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• 12V car battery (BCI Group 35 equivalent) - Qty: 1
• Battery terminal anti-corrosion spray - Qty: 1
• Battery terminal felt washers - Qty: 2

---

📋 Before You Begin

• Park on level ground and put the shifter in Park.
• Turn everything off (headlights, HVAC, radio), then open the hood.
• If you want to keep radio presets/clock, use a memory saver (plugs into the OBD port) before disconnecting the battery.
• Identify the terminals: negative (-) is usually black, positive (+) is usually red.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Access the battery

• Open the hood and locate the battery in the engine bay.
• If your Optima has a plastic battery cover, lift it off by hand.

Step 2: Disconnect the negative (-) terminal first

• Use a 10mm socket with a ratchet to loosen the negative terminal clamp nut.
• Twist and lift the clamp off the battery post, then tuck it aside so it can’t spring back.
• Terminal “clamp” is the metal ring on the post.

Step 3: Disconnect the positive (+) terminal

• Flip up/remove the red protective cap (if equipped).
• Use a 10mm socket with a ratchet to loosen the positive terminal clamp nut.
• Remove the clamp and position it so it cannot touch metal.

Step 4: Remove the battery hold-down bracket

• Use a 12mm socket, ratchet, and 6" extension to remove the hold-down bolt(s).
• Lift out the hold-down bracket and set it aside.

Step 5: Remove the old battery

• Carefully lift the battery straight up and out. It’s heavy, so use both hands and keep it upright.

Step 6: Clean the terminals and tray

• Use a battery terminal brush (specialty) to clean corrosion from the inside of both clamps.
• Wipe any debris off the battery tray area with a dry rag (do not use water on electrical parts).

Step 7: Install the new battery

• Place the new battery into the tray in the same orientation as the old one (positive and negative on the same sides).
• Reinstall the hold-down bracket and tighten using a 12mm socket and torque wrench: Torque to 9.8-11.8 Nm (87-104 in-lbs).

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

• Install the positive (+) clamp first. Use a 10mm socket and torque wrench: Torque to 4.0-6.0 Nm (35-53 in-lbs).
• Install the negative (-) clamp last. Use a 10mm socket and torque wrench: Torque to 4.0-6.0 Nm (35-53 in-lbs).
• Install felt washers (if used) and apply battery terminal anti-corrosion spray after tightening.

Step 9: Refit cover and final check

• Reinstall the battery cover (if equipped).
• Gently try to move the battery by hand; it should not shift.

---

✅ After Repair

• Start your Optima and confirm it cranks strongly and idles normally.
• Reset the clock and radio presets if they were lost.
• If the steering feels “heavy” at first, turn the wheel lock-to-lock once while parked to help the system relearn.
• Check that no battery warning light stays on.

---

💰 DIY vs Shop Cost

Shop Cost: $200-$450 (parts + labor)

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

You Save: $60-$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.