Disconnect and Reconnect the Battery

Last updated: June 5, 2026

Disconnecting the 12 V battery on a Peugeot 208 Mk1 (A9, 2012–2019) is a routine job, but the 208 has a built-in electronic delay you must respect: after switching off you need to wait a few minutes for the BSI (the body control computer) to go to sleep before you lift the leads, or you risk logging faults. This guide covers the safe sequence and the resets the 208 needs afterwards.

Where the Battery Is

The battery is in the engine compartment. Lift any cover to reach the two clamps. Cars with stop/start use an uprated battery — replace like-for-like.

Before You Disconnect

• Check your audio system security code in case the head unit asks for it.
• Park on a level surface, apply the handbrake and put the gear lever in neutral.
• Close all the doors and windows, then lock the car with the mechanical key blade and leave it — this helps the BSI power down.
• Turn the engine off, remove the key, and wait at least 4 minutes for the BSI to go to sleep before disconnecting.
• If working near airbags or seat-belt pretensioners, wait a further 5 minutes after disconnecting before handling those parts.

Disconnecting — Correct Order

1. With the BSI asleep (after the 4-minute wait), open the bonnet.
2. Slacken the negative (−, earth) terminal first and lift the lead clear, tucking it aside.
3. Only undo the positive (+) terminal if you are removing the battery completely.
4. If removing the battery, undo the base clamp and lift it out upright.

Reconnecting — Correct Order

1. Refit the battery and secure the hold-down clamp.
2. Connect the positive (+) lead first, then the negative (−) earth lead last. Tighten both firmly.
3. Wait about 2 minutes, then start the engine.

What to Reset Afterwards

• Reset the date and time and re-enter the radio code/presets.
• Re-initialise the electric windows — hold each close switch until shut, then a second more (see our 208 window guide).
• Check the remote locks/unlocks the car — re-sync it if needed.
• Check the parking brake and sunroof operation, and let the stop/start system re-initialise over a drive on a healthy battery.

If a Warning Light Stays On

One or two lights right after reconnecting is normal and should clear on a short drive. If the airbag, ABS or engine light remains, a fault code was logged. Reading it needs an OBD scanner — you can look up what a 208 code means on our sister site autodtcs.com.

Tools You Need

• 10 mm spanner/socket for the terminal clamps and hold-down.
• Optional memory-saver to preserve presets and settings.
• Your radio keycode, if the head unit is code-protected.

Frequently Asked Questions

Why do I have to wait 4 minutes before disconnecting a 208 battery?

The BSI body computer stays awake for a few minutes after you switch off. Disconnecting while it is still active can corrupt settings or log faults, so you let it go to sleep first.

How long should I leave it disconnected to reset the electronics?

Around 15 minutes with the doors shut lets the modules power down fully, clearing most transient glitches.

Why won’t my windows auto-close after reconnecting?

Expected — the one-touch disables itself after a power loss. Re-initialise each window and it returns.

My remote stopped working after the battery change — what now?

Check it locks/unlocks with a fresh fob battery; the 208 normally retains pairing, but a re-sync (using the key in the ignition) may be needed after a power loss.

To clear the service reminder after maintenance, see our Peugeot 208 service indicator reset guide.