This page is an extension of 56 Tactical Patterns That All Chess Players Should Know.
A battery is formed when two or more long-range pieces line up on the same file, rank, or diagonal. The combined power of these pieces can create powerful threats.
Here are three examples of Batteries.
Example #1

1. Bxf6 Bxf6 2. Qe4
White removes an important defender with 1. Bxf6, then creates a queen + bishop battery threatening 2. Qxh7#. White is also threatening 2. Qxa8.
Example #2

1. Qg8+ Rd8 2. Ra8+
Example #3

1. Qc1 Rbc8 2. Ba4 threatening 3. b5