These instructions apply to the MG MG3 Mk1 (SZP1) 2011-2023. For other models, please choose your vehicle here.
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Renewing a flat battery or disconnecting for other work on your MG3 (2011–2023)? 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. The MG3 is a conventional petrol car with no high-voltage system.
Disconnecting
- Switch everything off, remove the key and wait a couple of minutes.
- Slacken the negative (−, black) terminal first and lift it clear.
- Release the positive (+, red) clamp only if you’re removing the battery.
Reconnecting
- Fit positive first, then negative, and tighten both firmly.
- Switch the ignition on, wait, then start.
Afterwards
Re-set the clock/radio and reset the tyre-pressure monitor. Let the car sit a minute before driving so the systems re-initialise.
Frequently Asked Questions
Where is the battery on an MG3?
In the engine bay — 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.
Disclaimer: The information on this page is provided for general guidance only. Always follow your official service manual and safety precautions when working on your vehicle. We are not responsible for errors, omissions, or any damage resulting from the use of this information.
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