🔧 Highlander - 12V Battery Replacement

On your Highlander, the 12V battery sits under the hood and powers the computers, locks, lights, and starting system. The job is mainly about safely disconnecting the old battery (negative first), swapping it, then reconnecting (positive first) without shorting anything.

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

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⚠️ Safety & Precautions

• ⚠️ Keep metal tools off both battery posts at the same time (can short).
• ⚠️ Remove the negative cable first, install it last.
• ⚠️ Wear gloves and safety glasses; batteries can vent acid.
• ⚠️ Do not lean over the battery while reconnecting.
• ⚠️ If your Highlander has Auto Start-Stop, the battery type may be different.

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🔧 Required Tools

You'll need the following tools for this repair:

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

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• 12V battery (match the size and CCA rating printed on your current battery label) - Qty: 1
• Battery terminal anti-corrosion spray - Qty: 1
• Battery terminal felt washers - Qty: 2

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📋 Before You Begin

• Park on level ground, shift to Park, and turn the ignition fully OFF.
• Open the hood and keep the key fob at least 10 feet away from your Highlander.
• If you want to preserve settings, use a memory saver (plugs into OBD-II). A “memory saver” is a small device that keeps power to modules while the battery is out.
• Quick check: confirm the battery is under the hood on the driver side.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Confirm your battery type (important)

• Look at the top label of the installed battery and note if it says AGM or EFB (enhanced flooded battery).
• If it does not say AGM/EFB, it’s typically a standard flooded 12V battery.

Step 2: Remove the negative (-) battery cable

• Use a 10mm socket and 3/8" drive ratchet to loosen the negative terminal clamp nut.
• Wiggle the clamp up and off the negative post and push it aside so it cannot spring back.
• Tip: Tuck it behind a hose for safety.

Step 3: Remove the positive (+) battery cable

• Use a 10mm socket and 3/8" drive ratchet to loosen the positive terminal clamp nut.
• Lift the clamp off the positive post, then reinstall the red protective cover over the terminal end if your Highlander has one.

Step 4: Remove the battery hold-down

• Use a 12mm socket, 3/8" drive ratchet, and 3" extension to remove the hold-down fasteners.
• Lift the hold-down bracket off and set it aside.

Step 5: Remove the old battery

• Lift the battery straight up and out (it’s heavy; use both hands).
• Keep it upright to avoid any acid spill.

Step 6: Clean and prep the terminals

• Use a battery terminal brush to clean both cable clamps until the metal looks bright.
• Install battery terminal felt washers if you’re using them.

Step 7: Install the new battery

• Set the new battery into the tray in the same orientation as the old one (posts on the same side).
• Reinstall the hold-down bracket using the 12mm socket, ratchet, and extension.
• Use a torque wrench (5-30 Nm range) and 12mm socket to tighten the hold-down fasteners to Torque to 19 Nm (14 ft-lbs).

Step 8: Reconnect the battery cables (positive first)

• Install the positive (+) clamp first, using the 10mm socket and ratchet.
• Use a torque wrench and 10mm socket to tighten to Torque to 5 Nm (44 in-lbs).
• Install the negative (-) clamp last, using the 10mm socket and ratchet.
• Use a torque wrench and 10mm socket to tighten to Torque to 5 Nm (44 in-lbs).

Step 9: Protect terminals

• Apply battery terminal anti-corrosion spray to the clamps/posts.

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✅ After Repair

• Start your Highlander and confirm normal cranking and no warning lights.
• Reset one-touch windows if needed: hold the window switch down 2 seconds, then up 2 seconds.
• Set the clock and radio presets if they were lost.
• If the check engine light comes on after replacement, scan codes (often low-voltage history codes clear after a few drive cycles).

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💰 DIY vs Shop Cost

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

DIY Cost: $180-$350 (parts only)

You Save: $70-$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.

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Two quick questions so I match the correct battery:

• 🧩 Does your Highlander have Auto Start-Stop (engine turns off at stops)?
• 🧩 What does your current battery label say: AGM, EFB, or neither?