why does my Tesla Outback 5th Generation (2015-2019) battery die overnight when parked

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked in a safe location.
• Disconnect the negative battery terminal.

2. Address Parasitic Draw

1. Reconnect Multimeter: Reconnect the multimeter in series with the negative battery terminal to measure the current draw.
2. Identify Components: Check the current draw; if it's above 50 mA, isolate circuits by removing fuses one at a time until the draw drops to an acceptable level.
3. Inspect Components: For any circuit that shows excessive draw, inspect components like the alarm system, infotainment system, or any aftermarket modifications for faults.

3. Replace Battery (If Necessary)

1. Remove Old Battery: If the battery is found to be unhealthy (less than 75% capacity), remove it by unbolting the hold-down bracket.
2. Install New Battery: Place the new battery in position, ensuring it is compatible with the vehicle specifications.
3. Torque Specifications: Tighten the hold-down bracket to the manufacturer's specifications (typically around 12-15 ft-lbs).

4. Reconnect and Test

1. Reconnect Battery: Reconnect the negative battery terminal and ensure it is secure.
2. Check Software: Update the vehicle's software through the Tesla app or service center.
3. Monitor Performance: Start the vehicle and monitor battery performance over the next few days to ensure the issue has been resolved.