Lexus Dead Car Battery Replacement DIY

Is your Lexus not starting due to a dead battery? Learn how to fix the problem by replacing the battery of your Lexus.

Signs Your Lexus Battery Is Failing

• Slow or labored cranking, especially on cold mornings
• Clicking when you turn the key or press start, with dim dash lights
• Electrical glitches: flickering lights, radio resets or random warning lights
• A battery warning light or a battery older than about four to five years
• Swollen case, leaking acid or heavy corrosion on the terminals

Confirm the Battery Is the Problem

• With the engine off, a healthy battery reads about 12.6 volts. Below about 12.2 volts it is significantly discharged.
• Most parts stores will load test the battery for free.
• With the engine running, voltage should read roughly 13.5 to 14.8 volts. If not, check the alternator before replacing the battery.
• Clean corroded terminals first; a poor connection can mimic a dead battery.

A scan tool such as the YOUCANIC UCAN-II Pro shows live battery and charging voltage on supported models, which helps you tell a worn battery from a charging problem.

Locked out with a dead battery? See how to manually unlock a Lexus.

What you will need

• Car Battery: Group size should be printed on the old battery housing.
• 10mm Open End Wrench
• Battery Terminal Brush
• Battery Protector
• Electrical Tape
• Gloves
• Safety Glasses

Procedure

1. Pull the hood release under the dashboard. 
2. Slide your hand under the hood and depress the safety lever under the hood to open the hood.
   • 1991-Lexus-LS400 opening hood
   • 2016-Lexus-GX-460 opening hood
   • 2007-Lexus-IS-250 opening hood
3. Gently remove the battery terminal covers (Be careful to avoid bridging the battery with tools)
   • Removing battery covers on 2004-Lexus-ES-330
   • Removing battery covers on 2010-Lexus-ES-350
4. Use the 10 mm open-end wrench to loosen (not remove) the nut on the negative battery terminal. The negative terminal is designated with a negative sign (: )
   • Lexus ES350 2010 battery negative terminal
5. Disconnect the negative terminal from the battery post.
6. Remove the positive (red cable) from the battery positive (+) post. Isolate both ends of the connectors to avoid shorts. 
   • 2010-Lexus-ES-350 battery positive terminal
7. Use a 10 mm wrench to remove the bracket on top of the battery. 
8. Remove the old battery.
9. Clean the battery bay and the connectors to remove the corrosion that builds up over time.
10. Fit in your new battery carefully on the battery tray.
11. Reinstall the bracket. Do not over-tighten the bracket, or you risk cracking the battery case. 
12. Use a wire brush to clean the battery terminals.
13. Connect the positive terminal first and make sure it is tight and secure.
14. Connect the negative terminal last.
15. Reinstall the battery terminal covers.
16. Dispose of your old battery properly. If you were charged a core fee when the new battery was purchased, return it to the store for a core refund.
17. Press unlock on your keyfob. Enter the vehicle and start the engine. If your car has a keyless start, start the engine by pressing the Start/Stop button. 
18. Synchronize windows and set radio stations.

Changing the car battery on a Lexus is an easy job you can perform at home. Do not short the battery terminals, or you risk causing electrical problems or blowing a fuse, preventing you from starting your Lexus. We do not recommend using a backup battery to keep the vehicle powered when changing the battery.

Ways to Take Care of Your Car’s Battery

• Perform regular maintenance on your car’s electrical system, like cleaning the terminals from corrosion.
• Avoid short trips as much as possible to allow the battery to charge through your car’s charging system.
• Limit parasitic drain by having your electrical accessories disconnected when storing the vehicle.
• Limit extreme temperature exposure to reduce the strain on the batteries.
• You can install a battery disconnect switch when storing the vehicle to avoid draining the battery.

Check these troubleshooting and repair guides for more help on your Lexus.

Frequently Asked Questions

How long does a Lexus battery last?

Usually about 3 to 5 years, less in hot climates or with frequent short trips.

Where is the battery on a Lexus hybrid?

On many Lexus hybrids the 12 volt battery is in the trunk or under the rear seat, not under the hood. Check your owner’s manual.

Do I need to reset anything after replacing a Lexus battery?

You may need to reset the clock, radio presets and the one touch windows. Some models also relearn idle as you drive.

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