These instructions apply to the Chrysler 300 Mk1 (LX) 2004-2011. For other models, please choose your vehicle here.
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Disconnecting the 12 V battery on a Chrysler 300 / 300C (LX, 2004–2011) is a routine job for a battery change or before electrical work. There’s no battery registration on this generation, but you should let the modules settle for a couple of minutes first and have your radio code ready. This guide covers the safe order of work.
Where the Battery Is
On most 300/300C models the battery is in the engine bay. Lift any cover to reach the two terminal clamps. Fit a like-for-like battery if you are renewing it — match the original size and cold-cranking rating, especially on the HEMI V8.
Before You Disconnect
- Note your radio code and personal settings.
- Turn the ignition off and make sure all electrical consumers are switched off.
- After switching off, wait 2 minutes before disconnecting — this lets the modules power down cleanly.
- If working near airbags or seat-belt pretensioners, allow the system to discharge before handling those parts.
Disconnecting — Correct Order
- Turn the ignition off and wait 2 minutes.
- Slacken the negative (−, earth) terminal first and lift the lead clear.
- Only undo the positive (+) terminal if you are removing the battery completely.
Reconnecting — Correct Order
- Connect the positive (+) lead first, then the negative (−) earth lead last. Tighten both firmly.
- Turn the ignition on for a few seconds before starting the engine.
What to Reset Afterwards
- Enter the radio code and reset the clock, presets and personal settings.
- If the power windows lose one-touch, re-teach each one by holding the switch fully up (closed) for a moment.
- The car may relearn its idle and transmission shift adaptives over the first few miles — a slightly different feel at first is normal.
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 stays on, a fault code was logged — reading it needs an OBD scanner, and you can look up what a Chrysler code means on autodtcs.com.
Frequently Asked Questions
Do I need to register a new battery on a 300C?
No — this generation has no battery coding. Fit the correct battery and restore your settings.
Where is the battery on a Chrysler 300?
In the engine bay on most models. (Note: the closely related Dodge Charger/Magnum sometimes mount it differently — on the 300/300C it’s under the bonnet.)
Will I lose my radio?
The unit may ask for its security code after a power loss. Have it ready, or use a memory-saver to avoid it.
How long should I leave it disconnected?
Around 10–15 minutes with the doors shut lets the modules power down fully.
To clear the oil-change reminder after a service, see our Chrysler 300 oil-change indicator reset guide.
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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