How to Replace the 12V Battery on a 2018 Hyundai Kona (Step-by-Step Guide)
Tools, parts, safety tips, and torque specs to fix slow cranking and no-start battery issues for 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025, 2026
How to Replace the 12V Battery on a 2018 Hyundai Kona (Step-by-Step Guide)
Tools, parts, safety tips, and torque specs to fix slow cranking and no-start battery issues for 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025, 2026
🔧 Kona - 12V Battery Replacement
You’ll remove the old 12V battery from the engine bay and install a new one. This fixes slow cranking, warning lights from low voltage, and “dead battery” no-start issues.
Difficulty Level: Beginner | Estimated Time: 0.5-1.0 hours
⚠️ Safety & Precautions
- ⚠️ Keep the key fob at least 10 feet away so the Kona stays fully off.
- ⚠️ Turn ignition OFF and remove any chargers from the 12V outlet.
- ⚠️ Batteries can vent hydrogen gas; do this in a well-ventilated area.
- ⚠️ Never let a tool touch both battery terminals at the same time.
- ⚠️ Always disconnect the negative (-) terminal first, reconnect it last.
- ⚠️ If your Kona has Auto Start-Stop (ISG), it typically uses an AGM battery—use the same type as installed.
🔧 Required Tools
You'll need the following tools for this repair:
- 10mm socket
- 12mm socket
- 3/8" ratchet
- 6" socket extension
- Torque wrench (5-30 Nm range)
- Battery terminal puller (specialty)
- Battery terminal cleaning brush
- Trim clip tool
- Memory saver (12V OBD-II) (specialty)
- Nitrile gloves
- Safety glasses
🔩 Required Parts
HowToo sells all the parts you need for this repair:
- 12V battery (correct fit for Kona) - Qty: 1
- Battery terminal anti-corrosion washers - Qty: 2
- Battery terminal protectant spray - Qty: 1
📋 Before You Begin
- Park on level ground, shift to Park, and set the parking brake.
- Open the hood and let the engine bay cool if it’s hot.
- If you want to keep radio presets and settings, connect a Memory saver (12V OBD-II) now (it feeds low power while the battery is out).
- Make sure lights, HVAC, and accessories are OFF.
🔨 Step-by-Step Instructions
Follow these steps in order:
Step 1: Access the battery
- Open the hood.
- If a plastic cover blocks access, remove it using a trim clip tool.
Step 2: Disconnect the negative (-) terminal first
- Use a 10mm socket and 3/8" ratchet to loosen the negative (-) terminal clamp nut.
- Lift the clamp straight up and off the battery post.
- If it’s stuck, use a battery terminal puller (specialty). Don’t pry on the battery case.
Step 3: Disconnect the positive (+) terminal
- Use a 10mm socket and 3/8" ratchet to loosen the positive (+) terminal clamp nut.
- Remove the clamp from the post, then move it aside so it cannot spring back.
Step 4: Remove the battery hold-down
- At the battery base, remove the hold-down bracket/bolts using a 12mm socket, 6" extension, and 3/8" ratchet.
- Set the bracket and hardware aside.
Step 5: Remove the old battery
- Wearing nitrile gloves and safety glasses, lift the battery straight up and out.
- Batteries are heavy—use your legs, not your back. Keep it upright.
Step 6: Clean and prep the terminals
- Use a battery terminal cleaning brush to clean the inside of both terminal clamps until shiny.
- Install battery terminal anti-corrosion washers if you’re using them.
Step 7: Install the new battery
- Place the new battery into the tray in the same orientation as the old one (positive and negative posts match the cables).
- Reinstall the hold-down bracket using a 12mm socket, extension, and torque wrench.
- Torque to 18-22 Nm (13-16 ft-lbs).
Step 8: Reconnect the positive (+) terminal first
- Install the positive (+) clamp onto the battery post.
- Use a 10mm socket and torque wrench to tighten the clamp nut.
- Torque to 6-8 Nm (53-71 in-lbs).
- Apply a light coat of battery terminal protectant spray.
Step 9: Reconnect the negative (-) terminal last
- Install the negative (-) clamp onto the battery post.
- Use a 10mm socket and torque wrench to tighten the clamp nut.
- Torque to 6-8 Nm (53-71 in-lbs).
- Apply a light coat of battery terminal protectant spray.
Step 10: Reinstall any covers
- Reinstall any battery/engine covers you removed using a trim clip tool.
✅ After Repair
- Start the Kona and confirm normal cranking.
- Check that no battery terminals can rotate by hand.
- Set the clock and restore radio presets if they reset.
- If auto-up window function stops working: fully close the window, then hold the switch UP for 3 seconds to re-initialize.
- If a warning light appears after replacement, recheck terminal tightness and cleanliness first.
💰 DIY vs Shop Cost
Shop Cost: $250-$450 (parts + labor)
DIY Cost: $140-$280 (parts only)
You Save: $110-$170 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.

















