However, a safe bet would be to look for a battery with a CCA rating of at least 600-700 CCA. Going higher won't hurt, but going lower could lead to starting problems, especially in cold weather.
To be absolutely certain, check your owner's manual. It will specify the recommended group size and CCA rating for your specific 2007 Ford Expedition. Alternatively, you can check the battery currently installed in your vehicle; the CCA rating will be printed on the battery's label. Using this information as a starting point will ensure you get a suitable replacement.
