Disconnect and Reconnect the Battery

Last updated: June 8, 2026

Disconnecting the 12 V battery on your Alfa Romeo 147 (2000–2011) — for a new battery, winter storage, or work near the airbags — is a straightforward job. The battery sits under the bonnet, in the engine bay.

Find the Battery First

The 12 V battery is in the engine compartment, in the usual front corner under a cover. Note your radio security code (older 147s with a coded radio) and your presets before you start.

Disconnecting Safely

1. Switch everything off and remove the key.
2. Disconnect the negative (−) terminal first, then the positive.
3. Working near airbags or seat-belt pretensioners? Wait a few minutes after disconnecting before such work.

Reconnecting and Re-initialising

Reconnect positive first, then negative. The 147 then relearns:

• Power windows — one-touch may need re-initialising (hold the switch fully up at the limit).
• Electric sunroof (if fitted) relearns its travel.
• Re-enter the clock and radio presets.

If Something Isn’t Right Afterwards

• Warning lights often clear after a short drive.
• A persistent light stores a code — look it up on autodtcs.com.
• Fit a like-for-like battery of the correct capacity.

Frequently Asked Questions

Where is the battery on an Alfa Romeo 147?

In the engine compartment, in the usual front corner under a cover.

Which terminal first?

Negative (−) off first, reconnect it last.

Do I need to recode anything?

Windows and sunroof may need a one-touch relearn, and you’ll re-enter the clock and presets (plus a coded radio if fitted).

How long should I wait near the airbags?

Give it a few minutes after disconnecting before working on airbags or pretensioners.

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