Disconnect and Reconnect the Battery

Reviewed by the Service Reset editor · Updated August 9, 2026 · How we verify
Quick referenceTools10 mm spannerTime~15 minMethodDisconnect negative terminal first

These instructions apply to the Land Rover Defender Mk2 (L663) 2020-Present.
For other models, please choose your vehicle here.

Disconnecting the 12 V battery on your Land Rover Defender (2020–present) trips a lot of owners up — it isn’t under the bonnet, it’s under one of the front seats, and there are a couple of must-do steps first or you can lock the car against yourself. Here’s the safe sequence for the L663 Defender.

Land Rover Defender Mk2 — the vehicle covered in this guide.
Land Rover Defender Mk2. Photo by Dinkun Chen via Wikimedia Commons, licensed CC BY-SA 4.0.

Find the Battery and Prepare

The 12 V battery sits under a front seat, beneath a cover — the under-bonnet terminals are for jump-starting only.

  1. Put the gear selector in ‘P’ and release the electronic parking brake (important — once power is gone you can’t release it electrically).
  2. Turn the ignition off and check that all the doors unlock (so you’re not locked out with the power disconnected).
  3. Move the seat fully forwards and remove the battery cover.
  4. Disconnect the negative (−) terminal first, then the positive.

Working near airbags or pretensioners? Allow a minute or two after disconnecting before starting.

Reconnecting

  1. Reconnect positive first, negative last, refit the cover and the seat.
  2. Switch the ignition on and re-initialise the power windows (one-touch is lost).
  3. Re-enter the clock and settings; the air suspension may need a short drive to settle.

Fitting a new or different battery? The battery monitoring system ideally needs registering with Land Rover equipment so it charges the new battery correctly — often why stop/start stays inactive for a while afterwards.

If Something Isn’t Right Afterwards

  • Windows won’t auto-close — run the window re-initialisation.
  • Warning lights after reconnection often clear after a short drive; a persistent one stores a code (decode on autodtcs.com).
  • Parking brake or air suspension messages usually clear once you drive and the systems relearn.

Frequently Asked Questions

Where is the battery on a Land Rover Defender (2020 on)?

Under one of the front seats — slide the seat fully forward and remove the cover. The under-bonnet terminals are only for jump-starting.

Why release the parking brake first?

The electronic parking brake needs power to release — do it before disconnecting so the car isn’t stuck braked.

Which terminal first?

Negative (−) off first, reconnect it last.

What needs resetting afterwards?

The power windows re-initialise, plus the clock and presets; the BMS and air suspension relearn by driving.

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

Independent guide — not affiliated with Land Rover. Always follow your official service manual and safety precautions. Read our full disclaimer.

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