🔧 K900 - Battery Replacement

Replacing the 12V battery restores reliable starting and prevents low-voltage glitches (warning lights, slow cranking, infotainment resets). The job is mostly basic hand tools, but you must disconnect and reconnect the terminals in the correct order to protect electronics.

Difficulty Level: Beginner | Estimated Time: 0.5-1.0 hours

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⚠️ Safety & Precautions

• ⚠️ Turn ignition OFF, remove key/fob, and keep it away from the car while you work.
• ⚠️ Wear eye protection and gloves; battery acid is corrosive.
• ⚠️ Always disconnect the negative ( - ) terminal first, and reconnect it last.
• ⚠️ Do not let a tool bridge between the battery positive and metal body parts (can cause a dangerous short).
• ⚠️ If your K900 has a battery sensor on the negative cable, do not pry or twist it; handle the cable gently.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• 10mm socket
• 12mm socket
• 3/8" ratchet
• 6" extension (3/8" drive)
• Torque wrench (5-60 Nm range)
• Trim clip remover
• Battery terminal brush
• Battery strap/lifting handle
• 12V memory saver (OBD-II style) (specialty)

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• 12V battery (OEM-equivalent for your K900; correct size/CCA) - Qty: 1
• Battery terminal anti-corrosion spray - Qty: 1
• Battery terminal felt washers (red/green) - Qty: 1 set

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📋 Before You Begin

• Park on level ground, shift to Park, and set the parking brake.
• Open the hood and keep it securely propped.
• If you want to preserve radio/seat memory, install a 12V memory saver (a device that keeps low power to the car while the battery is disconnected). Follow the memory saver’s instructions before disconnecting the battery.
• Make sure all lights and accessories are OFF (headlights, cabin lights, HVAC, charging cables).

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Access the battery

• Open the hood and locate the battery in the engine bay.
• If there’s a plastic cover or air duct in the way, remove it using a trim clip remover and/or a 10mm socket.

Step 2: Disconnect the negative ( - ) battery terminal

• Use a 10mm socket to loosen the negative terminal clamp nut.
• Wiggle the clamp upward and off the battery post. If it’s stuck, gently rotate it while lifting—do not pry hard on the cable.
• Tuck the negative cable end to the side so it cannot spring back and touch the battery post.
• Torque to OEM specification when reinstalling.

Step 3: Disconnect the positive ( + ) battery terminal

• Flip open the red protective cap (if equipped).
• Use a 10mm socket to loosen the positive terminal clamp nut.
• Lift the clamp off the battery post and position it so it cannot touch metal body parts.
• Torque to OEM specification when reinstalling.

Step 4: Remove the battery hold-down

• Locate the hold-down bracket at the base of the battery.
• Use a 12mm socket with a 3/8" ratchet and extension to remove the hold-down bolt(s).
• Remove the hold-down bracket and set it aside.
• Torque to OEM specification when reinstalling.

Step 5: Remove the old battery

• Attach a battery strap/lifting handle and lift the battery straight up and out.
• Set it on the ground upright (do not tip it).
• Batteries are heavy; lift with legs.

Step 6: Clean and prep the terminals

• Inspect the battery tray for corrosion or moisture. Wipe clean.
• Use a battery terminal brush to lightly clean the inside of both terminal clamps until the metal looks bright.
• Install battery terminal felt washers on the posts (red on +, green on -) 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.
• Confirm it sits flat and the cables reach without stretching.

Step 8: Reinstall the battery hold-down

• Reinstall the hold-down bracket using a 12mm socket.
• Tighten with a torque wrench: Torque to OEM specification.
• The battery should not move when you try to wiggle it by hand.

Step 9: Reconnect the positive ( + ) terminal first

• Install the positive clamp fully down on the battery post.
• Tighten using a 10mm socket, then finish with a torque wrench: Torque to OEM specification.
• Close the red protective cap (if equipped).

Step 10: Reconnect the negative ( - ) terminal last

• Install the negative clamp fully down on the battery post.
• Tighten using a 10mm socket, then finish with a torque wrench: Torque to OEM specification.
• Apply battery terminal anti-corrosion spray to both terminals (light coat).

Step 11: Reinstall any covers/ducts

• Reinstall any battery covers or ducts removed earlier using the trim clip remover and 10mm socket.

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✅ After Repair

• Start the engine and confirm normal cranking speed and no flickering lights.
• Set the clock and check radio presets (if you didn’t use a memory saver).
• If the auto-up window function lost memory: with the engine running, use the window switch to fully lower the window, then fully raise it and hold the switch up for 2-3 seconds.
• Verify no battery warning light remains on after starting.

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💰 DIY vs Shop Cost

Shop Cost: $250-$450 (parts + labor)

DIY Cost: $180-$350 (parts only)

You Save: $70-$150 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.

Assumption: Torque values vary by production; use OEM torque specs for terminal and hold-down fasteners.