why does my Toyota Highlander XU70 (2020-Present) battery die overnight

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, wire brush, battery terminal cleaner
• Ensure safety by wearing gloves and eye protection.

2. Clean Battery Terminals

• Disconnect the negative battery terminal first, followed by the positive terminal.
• Use a wire brush and battery terminal cleaner to remove corrosion from the terminals and battery posts.
• Reconnect the terminals, starting with the positive terminal followed by the negative terminal.

3. Address Parasitic Draw

• If a parasitic draw is detected, systematically remove fuses one at a time to identify the circuit causing the draw.
• Once identified, inspect and repair or replace the faulty component (e.g., interior lights, radio, etc.).

4. Inspect and Replace Battery

• If the battery is found to be weak or faulty, replace it with a new, compatible battery.
• Ensure the new battery has the correct specifications for the Highlander (typically a Group 35 or Group 24F).
• Tighten the battery terminals securely.

5. Test Charging System

• Start the vehicle and check the voltage at the battery with a multimeter; it should read between 13.7-14.7 volts.
• If not, check the alternator connections and consider replacing the alternator if malfunctioning.