How to Replace the 12V Battery on a 2021 Honda Passport (Step-by-Step Guide)
Tools, parts list, safety tips, and torque specs for a fast under-hood battery swap for 2019, 2020, 2021, 2022, 2023, 2024, 2025
How to Replace the 12V Battery on a 2021 Honda Passport (Step-by-Step Guide)
Tools, parts list, safety tips, and torque specs for a fast under-hood battery swap for 2019, 2020, 2021, 2022, 2023, 2024, 2025
🔧 Passport - 12V Battery Replacement
Replacing the 12V battery on your Passport is a straightforward under-hood job. The key is to disconnect the cables in the correct order (negative first) to prevent electrical damage or sparks.
Difficulty Level: Beginner | Estimated Time: 0.5-1.0 hours
⚠️ Safety & Precautions
- ⚠️ Turn the ignition fully OFF and keep the key fob at least 10 feet away.
- ⚠️ Disconnect the negative (-) cable first, reconnect it last.
- ⚠️ Do not allow a tool to touch both the battery terminal and body metal.
- ⚠️ Your Passport’s negative terminal area may include a battery sensor; don’t pry or twist on the sensor housing.
- ⚠️ Wear safety glasses and gloves; batteries can vent corrosive acid.
🔧 Required Tools
You'll need the following tools for this repair:
- 10mm socket
- 10mm wrench
- 12mm socket
- Ratchet (3/8")
- 6" extension (3/8")
- Torque wrench (in-lb or Nm capable)
- Battery terminal puller (specialty)
- Battery strap or carrier handle
- Battery terminal brush
- Baking soda
- Clean water
- Shop towels
- Nitrile gloves
- Safety glasses
🔩 Required Parts
HowToo sells all the parts you need for this repair:
- 12V battery (correct fitment for your Passport) - Qty: 1
- Battery terminal anti-corrosion washers - Qty: 2
- Battery terminal protectant spray - Qty: 1
📋 Before You Begin
- Park on level ground, shift to P, and turn the ignition OFF.
- Open the hood and let the vehicle sit for 3 minutes so modules go to sleep.
- If you want to keep memory settings, you can use a memory saver (optional). Skip it if you’re unsure.
- Make sure you know any custom settings you want to restore (clock, radio presets, etc.).
🔨 Step-by-Step Instructions
Follow these steps in order:
Step 1: Access the battery
- Open the hood and locate the 12V battery in the engine bay.
- If there’s a top cover/insulator, remove it by hand and set it aside.
Step 2: Disconnect the negative (-) cable
- Use a 10mm wrench to loosen the negative terminal clamp nut.
- Wiggle the clamp and lift it straight up off the negative post.
- Move the cable aside so it can’t spring back to the terminal.
- Negative off first prevents accidental shorting.
- When reinstalling later: Torque to 5 N·m (44 in-lb)
Step 3: Disconnect the positive (+) cable
- Flip open the positive terminal cover if equipped.
- Use a 10mm wrench to loosen the positive terminal clamp nut.
- Lift the clamp straight up and move it aside (keep it from touching metal).
- When reinstalling later: Torque to 5 N·m (44 in-lb)
Step 4: Remove the battery hold-down
- Use a 12mm socket, ratchet (3/8"), and 6" extension to remove the hold-down nuts/bolts.
- Lift off the hold-down bracket and J-hooks (if equipped) and set them aside.
- When reinstalling later: Torque to 9 N·m (80 in-lb)
Step 5: Remove the old battery
- Use a battery strap or carrier handle to lift the battery straight up and out.
- Set it on the ground upright (don’t tip it).
Step 6: Clean the tray and terminals (if needed)
- If you see white/green crust, mix a small amount of baking soda with clean water.
- Use shop towels to wipe the tray and the cable ends; keep the mixture off paint as much as possible.
- Use a battery terminal brush to clean the inside of each cable clamp until shiny.
- Dry everything with shop towels.
Step 7: Install the new battery
- Place the new battery into the tray in the same orientation as the old one.
- Reinstall the hold-down bracket using the 12mm socket, ratchet (3/8"), and 6" extension.
- Torque to 9 N·m (80 in-lb)
Step 8: Reconnect the cables (positive first)
- Install anti-corrosion washers (if using) on the posts.
- Push the positive (+) clamp fully down onto the post, then tighten with a 10mm wrench.
- Torque to 5 N·m (44 in-lb)
- Push the negative (-) clamp fully down onto the post, then tighten with a 10mm wrench.
- Torque to 5 N·m (44 in-lb)
- Spray battery terminal protectant on the terminals if using.
Step 9: Final reassembly
- Reinstall any battery cover/insulator by hand.
- Remove tools and close the hood.
✅ After Repair
- Start the engine and confirm it cranks normally.
- Check for a solid connection: headlights should not flicker at idle.
- Reset the clock and restore presets if needed.
- If the auto-up/down windows don’t work, initialize by fully lowering and fully raising each window using the switch.
💰 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.
🎯 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.

















