The Postal Battery Exam is an assessment utilized by the United States Postal Service to test basic functions of a mail carrier. Comprised of 398 questions spanning 129 minutes, it tests form completion, address checking, address coding and personality characteristics. Specific requirements for each section can be found from a variety of resources, explaining what is required for a proper address and so forth.
Prepare for the exam by looking at a few practice exams. Many of these are available both online and in book form. These practice questions will show you how questions are posed in each section, so that you will know what to expect on the exam itself.
On the United States Postal Service website--usps.com--search for an employment position in your area, and fill out an application. The application will require basic employment information, so fill this out accurately.
The United States Postal Service will send you an email requesting you take Test 473, or the Postal Battery Exam. They will note whether you need to schedule a proctored exam, or if you may simply take the online assessment, and will have specific instructions for each scenario. It should be noted that you only have 14 days to complete the exam, so be sure to sign up as soon as possible.
Avoid sites that are not the United States Postal Service themselves. Many sites will request that you register or even pay a fee to take the exam, but this in unnecessary and the test itself is only offered through the USPS.