Disconnect and Reconnect the Battery

Disconnecting the 12 V battery on your Bentley Continental GT / GTC (393/394, 2011–2017) is a job owners take on for a new battery, winter storage on a maintenance charger, or to make the car electrically safe before work near the airbags and pretensioners. There is one thing that makes this car different from most: it has a dual-battery setup — a main battery and a separate starter battery — both in the boot. That is not as complicated as it sounds, and with the correct disconnect and reconnect order the Continental relearns its handful of lost settings over the first short drive.

Where the Batteries Are

Both batteries live in the luggage compartment (boot), under the carpet and covers — a main battery and a dedicated starter battery. Lift the boot carpet and remove the covers to reach them, and take note of the labelling that tells you which is which. Each has a negative (−) earth post and a positive (+) post under a cap. Identify the terminals on the battery you need before you touch a spanner — the disconnect and reconnect order is what keeps the job safe and avoids a short.

Before You Begin

• Switch the ignition fully off, take the key out of the car and keep it out of range so nothing wakes the car back up.
• Make sure the lights, climate, boot lid and interior electrics are all off before you begin.
• Note down your radio presets, clock and personal settings, and keep any stored security code to hand if the car uses one.
• Wait about 60 seconds after switching off so the control modules power down and settle.
• Have gloves and eye protection ready and the correct spanner for the terminal clamps.

Disconnecting

1. Turn the ignition off and wait about 60 seconds for the modules to sleep.
2. Remove the luggage-compartment carpet and lift off the relevant battery cover, following the labelling in the boot.
3. Disconnect the earth/negative (−) cable first, then move it aside so it cannot spring back onto the post.
4. Now disconnect the positive (+) cable. If you are working near airbags or pretensioners, wait a few more minutes first.

Reconnecting

1. Reconnect the positive (+) cable first and tighten the clamp — there is no need to grease the terminals.
2. Reconnect the earth/negative (−) cable last and tighten it down securely.
3. Refit the covers and boot carpet, then let the car settle for a minute before starting.

What You’ll Need to Reset Afterwards

A disconnect clears the short-term memory of a few systems. On the Continental expect to sort out:

• Clock and radio presets — re-enter them, along with any security code the car prompts for.
• Power windows — re-initialise one-touch and anti-pinch by holding each switch at the fully closed and fully open limits.
• Air suspension re-levels itself once you start driving.
• Seat, mirror and other personal preferences may need re-selecting if they were lost.
• Any warning lights that appear on start-up usually self-clear after a short drive as the systems re-check.

If a Warning Light Stays On or the Car Feels Off

• Re-check the terminal clamps on the battery you worked on are properly tight — a loose earth is the most common cause of odd behaviour.
• Take a short, gentle drive so the windows, suspension and other systems can relearn.
• If a window will not one-touch, repeat the hold-at-the-limits re-initialisation.
• Rule out a genuinely flat or worn-out battery — with two batteries, a weak one can cause odd symptoms, so check the state of both.
• If a light will not clear, it has stored a code — look it up on autodtcs.com.

Frequently Asked Questions

Where is the battery on a Bentley Continental GT (393)?

In the luggage compartment (boot), under the carpet and covers. There are two — a main battery and a dedicated starter battery — not one battery in the engine bay.

Why are there two batteries?

The Continental uses a main battery plus a separate starter battery to handle its heavy electrical load. For normal work, follow the cover labelling in the boot to identify the one you need.

Which terminal do I disconnect first?

The earth/negative (−) cable comes off first and goes back on last. When reconnecting, fit the positive (+) first, then the negative.

What will I need to reset afterwards?

Mainly the clock and radio presets, window one-touch, and any seat or mirror preferences. The air suspension re-levels on its own once you drive.

Do I need to recode anything?

Like-for-like batteries of the correct type and rating generally need no coding to drive away. Only re-enter a security code if the car specifically asks for one, and let the car relearn its state over the first few drives.

How long should I wait near the airbags?

Give it a few minutes after disconnecting before working on airbags or pretensioners, so any residual energy in those circuits has fully dissipated.

If a warning light stays on after reconnecting, look up the code on autodtcs.com.