Chess Wiki
Battery on the c file
a b c d e f g h
8 a8 rd b8 c8 kd d8 e8 nd f8 g8 h8 8
7 a7 b7 bd c7 pd d7 e7 f7 g7 h7 7
6 a6 b6 pd c6 d6 pd e6 f6 g6 h6 6
5 a5 b5 c5 d5 e5 pd f5 g5 h5 5
4 a4 pd b4 pl c4 d4 e4 f4 g4 pd h4 4
3 a3 pl b3 c3 rl d3 e3 f3 g3 pl h3 pd 3
2 a2 b2 c2 ql d2 e2 f2 pl g2 h2 pl 2
1 a1 b1 c1 d1 e1 f1 rl g1 kl h1 1
a b c d e f g h
The queen and rook target the c7 pawn, and the
f rook could potentially join the battery as well.

A chess battery is a structure where two (or more) pieces are "stacked" on the same file, rank, or diagonal. Each piece can move along the line while also being defended by the other piece, making them replaceable when captured. Their expendability is used to target and add pressure to certain pieces. However, some minor disadvantages are that they cover less area when they are stacked, and the two pieces can block each other and cause congestion. They are made of either two rooks, a queen and a rook, a queen and bishop, and two bishops (with underpromotion, but it is very uncommon). This tactic can be used to create threats against the enemy king, or earn material. Most commonly used are two rooks; they can switch files or ranks almost anywhere with ease. They often target the king using their expansive range and threaten checkmate.