🔧 Fusion - Battery Replacement

Replacing the 12-volt battery on your Fusion involves removing the old battery from the engine bay, installing the new one, and making sure the Battery Monitoring System relearns the replacement. The battery powers starting, lighting, modules, and many memory functions, so clean connections and correct installation matter.

Difficulty Level: Beginner | Estimated Time: 30-60 minutes

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⚠️ Safety & Precautions

• ⚠️ Wear safety glasses and gloves. Car batteries contain acid and can release explosive gas.
• ⚠️ Always disconnect the negative cable first and reconnect it last. This lowers the chance of accidental short circuits.
• ⚠️ Do not touch a wrench between the positive terminal and body metal. That can cause sparks or damage modules.
• ⚠️ Keep the key fob away from the vehicle while working so modules stay asleep.
• ⚠️ The battery is heavy. Lift straight up with both hands or use a battery carrier strap.
• ⚠️ Battery disconnect is required for this repair.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 8mm socket
• Ratchet wrench 3/8-inch drive
• 6-inch extension 3/8-inch drive
• Battery terminal puller (specialty)
• Battery post and terminal cleaning brush
• Digital multimeter
• Torque wrench 1/4-inch drive inch-pound
• Memory saver OBD-II 12-volt (optional specialty)
• Battery carrier strap (optional specialty)
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• 12-volt AGM battery - Qty: 1
• Battery terminal protectant spray - Qty: 1
• Battery terminal anti-corrosion washers - Qty: 2

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📋 Before You Begin

• Park your Fusion on level ground, shift to Park, and set the parking brake.
• Turn off the ignition, headlights, climate control, radio, and all accessories.
• Open the hood and wait at least 5 minutes so vehicle modules can go to sleep.
• If using a memory saver, it plugs into the OBD-II port under the driver side dash and helps preserve radio presets and learned settings.
• If you do not use a memory saver, some settings may reset. This is normal.
• The Battery Monitoring System should be reset after replacement so charging behavior matches the new battery.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Open the Hood and Locate the Battery

• Use the interior hood release, then open the hood and support it securely.
• The battery is in the engine bay on the driver-side area near the front corner.
• Use safety glasses and nitrile gloves before touching the battery.
• Take a photo before removing cables.

Step 2: Connect the Memory Saver if Used

• Use the memory saver OBD-II 12-volt and plug it into the OBD-II port below the driver-side dash.
• A memory saver is a small backup power source that keeps low-current vehicle memories alive during battery replacement.
• Make sure the memory saver shows power before disconnecting the battery.

Step 3: Remove the Negative Battery Cable

• Use a 10mm socket with the ratchet wrench 3/8-inch drive to loosen the negative terminal clamp nut.
• The negative terminal is marked with a minus symbol: -.
• Twist the terminal gently and lift it off the battery post.
• If it is stuck, use the battery terminal puller. A terminal puller lifts the clamp evenly without breaking it.
• Move the negative cable away from the battery so it cannot spring back and touch the post.

Step 4: Remove the Positive Battery Cable

• Open the red positive terminal cover by hand.
• Use a 10mm socket with the ratchet wrench 3/8-inch drive to loosen the positive terminal clamp nut.
• The positive terminal is marked with a plus symbol: +.
• Lift the positive cable off the battery post and move it aside.
• Do not let the tool touch body metal while it is on the positive terminal.

Step 5: Remove the Battery Hold-Down

• Use an 8mm socket, 6-inch extension 3/8-inch drive, and ratchet wrench 3/8-inch drive to remove the battery hold-down fastener at the lower edge of the battery tray.
• The hold-down is the clamp that keeps the battery from moving while driving.
• Remove the hold-down bracket and set it aside.

Step 6: Remove the Old Battery

• Use a battery carrier strap if available, or grip the battery firmly with both hands.
• Lift the battery straight up and out of the tray.
• Keep the battery upright. Do not tip it sideways.
• Place it on the ground away from your work area.

Step 7: Clean the Battery Tray and Cable Ends

• Use the battery post and terminal cleaning brush to clean the inside of both cable terminals.
• Use the same brush to clean any corrosion from the tray area.
• Corrosion looks like white, green, or blue crust around the terminals.
• If heavy corrosion is present, avoid breathing dust and wipe the area carefully with a damp disposable towel.

Step 8: Install the New Battery

• Use the battery carrier strap or both hands to lower the new battery into the tray.
• Make sure the positive post is on the same side as the positive cable.
• Install the battery hold-down bracket.
• Use the 8mm socket, 6-inch extension 3/8-inch drive, and torque wrench 1/4-inch drive inch-pound to tighten the hold-down fastener.
• Torque to 6 Nm (53 in-lbs)
• Do not overtighten the battery clamp.

Step 9: Connect the Positive Cable First

• Install one battery terminal anti-corrosion washer on the positive post if supplied.
• Place the positive cable onto the positive battery post.
• Use a 10mm socket and torque wrench 1/4-inch drive inch-pound to tighten the positive terminal clamp nut.
• Torque to 5 Nm (44 in-lbs)
• Close the red positive terminal cover by hand.

Step 10: Connect the Negative Cable Last

• Install one battery terminal anti-corrosion washer on the negative post if supplied.
• Place the negative cable onto the negative battery post.
• Use a 10mm socket and torque wrench 1/4-inch drive inch-pound to tighten the negative terminal clamp nut.
• Torque to 5 Nm (44 in-lbs)
• Spray a light coat of battery terminal protectant spray on both terminals after tightening.

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 fully charged new battery should usually 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.

Step 12: Reset the Battery Monitoring System

• Sit in the driver seat and close all doors.
• Turn the ignition to ON without starting the engine.
• Use the headlight switch to flash the high beams 5 times.
• Press and release the brake pedal 3 times.
• Watch the battery warning light on the instrument cluster. It should flash to confirm the Battery Monitoring System reset.
• If it does not flash, repeat the sequence carefully after waiting 30 seconds.

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✅ After Repair

• Start your Fusion and let it idle for 2-3 minutes.
• Confirm the battery warning light turns off after startup.
• Check that the terminals are tight by gently trying to rotate each cable by hand. They should not move.
• Reset the clock, radio presets, one-touch windows, and other preferences if needed.
• If the automatic windows lost one-touch operation, fully close each window and hold the switch up for 2 seconds, then fully open and hold down for 2 seconds.
• Drive normally. Idle quality and shifting may feel slightly different while the vehicle relearns after battery disconnect.
• Recycle the old battery at a parts store or recycling center. Do not throw it in household trash.

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💰 DIY vs Shop Cost

Shop Cost: $230-$420 (parts + labor)

DIY Cost: $160-$280 (parts only)

You Save: $70-$140 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.