🔧 Highlander - 12V Battery Replacement

This repair replaces the under-hood 12-volt starting battery in your Highlander. A weak battery can cause slow cranking, warning lights, no-start issues, and electronic glitches.

Difficulty Level: Beginner | Estimated Time: 20-40 minutes

---

⚠️ Safety & Precautions

• ⚠️ Battery acid can burn skin and eyes. Wear safety glasses and gloves.
• ⚠️ Remove the negative cable first and install it last. This helps prevent accidental short circuits.
• ⚠️ Do not let a wrench touch the positive battery post and any metal body part at the same time.
• ⚠️ Keep sparks, cigarettes, and open flames away from the battery.
• ⚠️ The battery is heavy. Lift with both hands and keep it upright.
• ⚠️ Battery disconnect may erase some learned settings. The engine may idle slightly differently for a short time after replacement.

---

🔧 Required Tools

You'll need the following tools for this repair:

• 10mm wrench
• 10mm socket
• 3/8-inch ratchet
• 6-inch extension
• Battery terminal puller (specialty)
• Battery terminal cleaning brush
• Battery carrying strap (specialty)
• Digital multimeter
• Memory saver 12V OBD-II device (specialty)
• Shop towels
• Nitrile gloves
• Safety glasses

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• 12V AGM or flooded lead-acid battery, Group 24F - Qty: 1
• Battery terminal corrosion protectant - Qty: 1
• Battery terminal anti-corrosion washers - Qty: 2

---

📋 Before You Begin

• Park your Highlander on level ground, shift to Park, and set the parking brake.
• Turn off the ignition, headlights, climate control, and all accessories.
• Open the hood and let the vehicle sit for a few minutes before disconnecting the battery.
• If using a memory saver, plug the memory saver 12V OBD-II device into the diagnostic port under the driver side dash before disconnecting the battery. A memory saver keeps small electronics powered so radio presets and learned settings are less likely to be lost.
• Locate the battery on the driver side of the engine bay.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Inspect the Battery Area

• Use safety glasses and nitrile gloves before touching the battery.
• Check for white, blue, or green crusty buildup around the terminals. This is corrosion, which can block electrical flow.
• Use shop towels to wipe loose dirt from the top of the battery.
• Take a photo before removal.

Step 2: Disconnect the Negative Battery Cable

• Find the negative terminal marked with a minus sign -. It usually has a black cable.
• Use a 10mm wrench to loosen the negative terminal clamp nut.
• Twist the clamp gently and lift it off the battery post.
• If the clamp is stuck, use a battery terminal puller (specialty). A terminal puller safely lifts the clamp without prying on the battery post.
• Move the negative cable aside so it cannot spring back and touch the battery.

Step 3: Disconnect the Positive Battery Cable

• Open the red protective cover on the positive terminal marked with a plus sign +.
• Use a 10mm wrench to loosen the positive terminal clamp nut.
• Lift the positive cable off the battery post.
• Keep the positive cable away from metal parts of the body and engine.

Step 4: Remove the Battery Hold-Down Bracket

• The hold-down bracket is the metal clamp that keeps the battery from moving.
• Use a 10mm socket, 3/8-inch ratchet, and 6-inch extension to loosen and remove the hold-down nuts.
• Remove the bracket and set it aside in the same direction it came off.
• Do not drop the J-hooks into the engine bay.

Step 5: Remove the Old Battery

• Use a battery carrying strap (specialty) if the battery does not have a handle. A carrying strap hooks to the battery so you can lift it more safely.
• Lift the battery straight up and out of the tray.
• Keep the battery upright at all times.
• Place it on the ground away from your work area.

Step 6: Clean the Battery Tray and Cable Ends

• Use shop towels to wipe dirt from the battery tray.
• Use a battery terminal cleaning brush to clean the inside of both cable clamps until the metal looks bright.
• If there is heavy corrosion, clean carefully and avoid breathing dust.
• Clean metal makes stronger contact.

Step 7: Install the New Battery

• Use a battery carrying strap (specialty) or the battery handle to lower the new 12V AGM or flooded lead-acid battery, Group 24F into the tray.
• Make sure the positive post is on the same side as before.
• The battery should sit flat and not rock in the tray.

Step 8: Reinstall the Battery Hold-Down Bracket

• Place the hold-down bracket over the battery.
• Use a 10mm socket, 3/8-inch ratchet, and 6-inch extension to tighten the hold-down nuts evenly.
• Torque to 5 Nm (44 in-lbs).
• Do not overtighten. The case can crack if clamped too hard.

Step 9: Connect the Positive Battery Cable

• Place one battery terminal anti-corrosion washer over the positive battery post.
• Push the positive cable clamp fully down onto the positive post.
• Use a 10mm wrench to tighten the clamp nut.
• Torque to 5.4 Nm (48 in-lbs).
• Close the red positive terminal cover.

Step 10: Connect the Negative Battery Cable

• Place one battery terminal anti-corrosion washer over the negative battery post.
• Push the negative cable clamp fully down onto the negative post.
• Use a 10mm wrench to tighten the clamp nut.
• Torque to 5.4 Nm (48 in-lbs).
• Apply battery terminal corrosion protectant lightly to both terminals after the clamps are tight.

Step 11: Check Battery Voltage

• Use a digital multimeter set to DC volts.
• Touch the red meter lead to the positive terminal and the black meter lead to the negative terminal.
• A healthy fully charged battery should read about 12.6 volts with the engine off.
• Start the engine and check again. Charging voltage should usually be about 13.5-14.8 volts.

---

✅ After Repair

• Start your Highlander and make sure it cranks normally.
• Check that the battery warning light turns off after the engine starts.
• Turn the steering wheel gently left and right if any steering or stability warning appears after battery disconnect.
• Reset the clock and radio presets if you did not use a memory saver.
• Initialize the power windows if auto-up/down does not work: fully lower each window, then fully raise it and hold the switch up for about 2 seconds.
• Let the engine idle for a few minutes. The computer may relearn idle speed after power loss.
• Recycle the old battery at an auto parts store or battery recycler. Do not throw it in household trash.

---

💰 DIY vs Shop Cost

Shop Cost: $220-$380 (parts + labor)

DIY Cost: $150-$260 (parts only)

You Save: $70-$120 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.3-0.6 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.