Where Is the Battery in a Chrysler 300?

The Chrysler 300’s vehicle battery is under an access cover in the trunk—not under the hood. The engine compartment has remote terminals for jump-starting. Chrysler’s 2005 owner’s manual, 2011 manual and 2023 manual all document that layout.

If you mean the key-fob battery, that is a separate coin cell inside the remote. Its access method depends on the fob design; see below. This guide concerns the modern Chrysler 300 sedan, not the older Chrysler 300M. For another model year, check its manual before applying the specific procedures below.

Find the vehicle battery in the trunk

1. Park safely, apply the parking brake, select PARK and switch the ignition off.
2. Open the trunk and move luggage off the floor panel.
3. Lift the trunk-floor access cover. The 2023 manual describes a pull strap for lifting the cover over the spare-tire storage area.
4. Locate the battery beneath the cover. You do not need to disconnect anything simply to find it.

See the 2023 manual’s “Jack Location/Spare Tire Stowage” and “Preparations For Jump Start” sections for the access-cover instructions and battery location.

Stop before replacement if you have not confirmed the correct battery. The 2023 manual warns that the trunk-mounted battery has a vent hose and must be replaced with the same type of vented battery. Do not leave that hose disconnected or choose a replacement solely because it fits the space. Confirm the specification for your model year and equipment before buying. Chrysler’s battery precautions also warn about acid, explosive gas and accidental electrical contact.

Need a jump-start? Look under the hood

For the documented 2011 and 2023 models, the remote positive and negative posts are on the vehicle’s right-hand side of the engine compartment. Use the owner’s-manual diagram rather than guessing from an exposed bolt or fuse-box connection. See the 2011 jump-start instructions or 2023 instructions; the latter describes viewing the posts while standing beside the right fender.

On the 2023 model:

• The positive post may have a protective cap; identify the + marking on or around the post.
• The remote negative post is an exposed, unpainted metal post directly behind the under-hood fuse box.
• Chrysler says not to jump from fuses and not to attach the final negative clamp to the discharged battery’s negative terminal in the trunk.

Follow the complete 2023 jump-start procedure and your booster’s instructions. Do not attempt to jump a frozen battery or use a source above 12 volts. If you cannot positively identify the posts, stop and get roadside assistance.

If the trunk release will not operate, you do not need trunk access merely to connect a booster at the designated under-hood posts. Repeatedly needing a jump is a reason to have the battery and charging system tested, not just keep boosting it.

Where is the Chrysler 300 key-fob battery?

The 2005 and 2023 manuals both specify one CR2032, but they describe different housings:

Documented fob	Battery access
2005 screw-fastened transmitter	With buttons facing down, remove the small screw, then separate the halves without damaging the rubber gasket.
2023 removable-emergency-key fob	Slide the release and withdraw the emergency key, then gently separate the halves with a coin or flat-blade screwdriver without damaging the seal. The cell is in the back cover.

These instructions come from the 2005 transmitter battery service section and 2023 key-fob battery replacement section. Match your actual housing and check its installed cell before applying either procedure, especially with an aftermarket remote.

Photograph the battery orientation before removal. For the documented 2023 fob, match the cell’s + sign to the + inside the battery clip. Avoid touching the circuit board or contacts, close the case securely, then test locking and unlocking. Keep new and used coin cells away from children. If the compartment will not close securely, stop using the fob and keep it away from children; suspected swallowing or insertion into the body requires immediate medical attention. See the 2023 replacement instructions and coin-cell warnings.

Dead fob battery or dead vehicle battery?

For the documented 2011 smart fob, the removable emergency key provides mechanical entry if either battery is dead. Its backup ignition method is to press the fob’s nose—the end opposite the emergency key—against the START/STOP button. The 2011 manual explains both functions.

That backup addresses a depleted fob battery; it does not supply power to a discharged vehicle battery. Likewise, replacing the CR2032 will not restore a dead dashboard or power trunk release. Start by identifying which battery-dependent functions have stopped working.