Disconnect and Reconnect the Battery

Last updated: June 6, 2026

Renewing a flat battery or disconnecting for other work on your MG ZS (2017–2021)? The 12 V battery is in the engine bay. Do it in the right order and the car relearns its settings cleanly.

Where the Battery Is

Open the bonnet — the 12 V battery sits in the engine compartment, usually under a plastic cover. The petrol ZS is a conventional car with no high-voltage system (the separate ZS EV is not covered here).

Disconnecting

1. Switch everything off, remove the key and wait a couple of minutes.
2. Lift the cover and slacken the negative (−, black) terminal first; lift it clear.
3. Release the positive (+, red) clamp only if you’re removing the battery.

Reconnecting

1. Fit positive first, then negative, and tighten both firmly.
2. Switch the ignition on, wait, then start.

Afterwards

Re-set the clock/radio and re-store your tyre pressures. If the service reminder needs clearing after the work, see our ZS service reset guide. Let the car sit a minute before driving.

Frequently Asked Questions

Where is the battery on an MG ZS?

In the engine bay under a plastic cover — a standard 12 V battery.

Which terminal comes off first?

Negative (−) off first; positive (+) on first when reconnecting.

What resets when I disconnect it?

Clock, radio presets and the tyre-pressure baseline typically need re-doing.

Do I need to code a new battery?

For a like-for-like replacement, no coding is needed for normal running.

This is a common job. If a warning light stays on afterwards, check the code on autodtcs.com.