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Lexus IS: How to Replace Your Battery

Learning how to change your Lexus' battery yourself will save you some cash in the long run while buying you peace of mind in the short term.

By Piyush Kayastha - November 11, 2014

This article applies to Lexus IS 250, IS 350 (2005-2014)

Your car's battery has a limited lifespan. Most of the time they'll last around four years, but they can fail before that. As it weakens, you'll start seeing symptoms appearing in other parts of your car. Flickering headlights, dim interior lights are some early signs. The tell-tale sign of a truly dead battery is a car that won't start. All you'll hear is a clicking sound without the engine turning over. If your vehicle is showing symptoms of a weak battery, it is advisable to replace it as soon as possible. The best part is that it's easy to do this yourself.

Tools Needed

  • 10mm socket wrench
  • 10mm crescent wrench
  • Wire brush
  • Flat head screw driver (to pry panels)

Step 1 - Remove battery terminals

Using the 10mm socket wrench, undo the nut to the negative (black) battery terminal. Repeat this step for the positive (red) battery terminal.

Figure 1 . The negative battery terminal is highlighted above. Remove with a 10mm socket.

Pro Tip

You can use bungee cords to strap the terminals aside and away from each other as to not make contact.

Step 2 - Remove hold down clamp

Using the 10mm crescent wrench, remove the nuts holding the clamp or battery tie down.

Figure 2. You'll need to remove this bracket to remove the battery.

Step 3 - Inspect and clean or replace battery terminals

Terminals can get corroded over time and lose their conductivity. Use a wire brush to clean the corrosion from the terminal clamps as well as the battery posts. It is a good time to replace the terminal(s) if the corrosion is heavy.

  • Figure 3. Your terminals should look similar to this. Replace them if they are corroded and causing electrical gremlins.
  • Figure 4. This battery has corroded significantly. Clean with a wire brush and replace the terminals if they're bad.

Step 4 - Replace battery

Remove old battery and replace it with the new one.

Figure 5. Above is the factory battery removed from the car. Recycle this at your local auto store. Many stores will pay you for them.

Step 5 - Reconnect battery terminals

Tighten the positive (red) cable down using the 10mm socket wrench. Repeat for the negative (black) terminal.

Step 6 - Reinstall battery clamp

Lay the clamp down over the battery and use the 10mm crescent wrench to tighten down the nut.

Step 7 - Start the car

Although the battery is brand new and fully charged, it is recommended to start the car and run it for a few minutes.

Featured Video: How to Replace Battery in Lexus IS 250

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