How to Replace the Battery on a 2018 Chevrolet Malibu (Trunk-Mounted 12V)
Step-by-step trunk access, tools/parts list, safety tips, and torque specs for a quick DIY swap
How to Replace the Battery on a 2018 Chevrolet Malibu (Trunk-Mounted 12V)
Step-by-step trunk access, tools/parts list, safety tips, and torque specs for a quick DIY swap


š§ Malibu - Battery Replacement
On your Malibu, the 12V battery is typically located in the trunk area under the floor/side trim. Youāll remove the access panels, disconnect the negative cable first, swap the battery, then reconnect and verify everything powers up normally.
Difficulty Level: Beginner | Estimated Time: 0.5-1.0 hours
ā ļø Safety & Precautions
- ā ļø Turn the ignition OFF, remove the key/fob, and keep it at least 10 feet away from your Malibu while you work.
- ā ļø Disconnect the negative (-) battery cable first to reduce the chance of accidental short circuits.
- ā ļø Do not allow tools to touch both a battery terminal and metal body parts at the same time.
- ā ļø Batteries are heavy and can leak acidāwear gloves and safety glasses.
- ā ļø If your Malibu has a vent tube on the battery, it must be reinstalled to vent gases safely.
š§ Required Tools
You'll need the following tools for this repair:
- 10mm socket
- 13mm socket
- 3/8" ratchet
- 6" extension for 3/8" ratchet
- Trim panel removal tool
- Torque wrench (5-30 Nm range)
- Battery terminal cleaning brush
- Work gloves
- Safety glasses
š© Required Parts
HowToo sells all the parts you need for this repair:
- 12V battery (AGM, H6/Group 48 equivalent) - Qty: 1
- Battery terminal protectant - Qty: 1
- Anti-corrosion felt washers (optional) - Qty: 1 set
š Before You Begin
- Park on level ground, shift to Park, and set the parking brake.
- Open the trunk and remove any cargo so you can access the battery area.
- If you want to preserve radio presets/settings, use a 12V memory saver (optional). If you donāt have one, thatās OKāyour Malibu will relearn most settings.
šØ Step-by-Step Instructions
Follow these steps in order:
Step 1: Access the battery compartment
- Open the trunk.
- Lift the trunk floor panel (spare-tire cover area).
- Use a trim panel removal tool to carefully release any plastic retainers/clips holding the battery access cover.
- Tip: Pry near clips, not in the middle.
Step 2: Identify the terminals and any vent tube
- Locate the negative (-) terminal (usually black) and the positive (+) terminal (usually under a red cover).
- If you see a small hose attached to the side of the battery, thatās the vent tube (it routes battery gases outside). Note how itās installed.
Step 3: Disconnect the negative (-) battery cable
- Use a 10mm socket with a 3/8" ratchet to loosen the negative terminal clamp bolt.
- Wiggle and lift the clamp off the negative post, then tuck it aside so it cannot spring back onto the post.
Step 4: Disconnect the positive (+) battery cable
- Flip open/remove the red terminal cover (if equipped).
- Use a 10mm socket with a 3/8" ratchet to loosen the positive terminal clamp bolt.
- Remove the clamp from the positive post and keep it from touching metal.
Step 5: Remove the battery hold-down
- Find the battery hold-down bracket/strap at the base of the battery.
- Use a 13mm socket, 6" extension, and 3/8" ratchet to remove the hold-down bolt.
- Set the hold-down parts aside where you wonāt lose them.
Step 6: Remove the old battery
- Lift the battery straight up and out. Use your legsābatteries are heavy.
- If a vent tube is attached, disconnect it gently by hand before lifting the battery fully out.
Step 7: Clean and prep the connections
- Use a battery terminal cleaning brush to clean the inside of the cable clamps if thereās corrosion.
- Wipe the area clean and ensure the battery tray is dry and solid.
Step 8: Install the new battery
- Place the new battery into the tray in the same orientation as the old one.
- Reconnect the vent tube (if equipped) by pushing it on fully by hand.
Step 9: Reinstall and torque the hold-down
- Reinstall the hold-down bracket/strap.
- Use a 13mm socket with a torque wrench to tighten the hold-down bolt: Torque to 15 Nm (11 ft-lbs).
Step 10: Reconnect the terminals (positive first)
- Install the positive (+) clamp onto the battery post.
- Use a 10mm socket with a torque wrench to tighten: Torque to 5 Nm (44 in-lbs).
- Reinstall the red positive terminal cover (if equipped).
- Install the negative (-) clamp onto the battery post.
- Use a 10mm socket with a torque wrench to tighten: Torque to 5 Nm (44 in-lbs).
- Apply a light coat of battery terminal protectant to help prevent corrosion.
Step 11: Reinstall trunk panels
- Reinstall the battery access cover and any retainers using the trim panel removal tool as needed.
- Reinstall the trunk floor panel.
ā After Repair
- Start your Malibu and confirm it cranks normally and the charging system warning light is off.
- Check that interior lights, radio, and power locks work.
- If the auto-up/down windows act weird, cycle each window fully down then fully up using the switch.
- If a battery warning message remains, you may need a battery sensor reset with a scan tool (some vehicles learn automatically after a few drive cycles).
š° DIY vs Shop Cost
Shop Cost: $250-$450 (parts + labor)
DIY Cost: $180-$320 (parts only)
You Save: $70-$130 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.
šÆ Ready to get started?
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