Example battery
Example battery - ? 1-0

1.Bh3+! 1... Kxh3 (1... Kh2 (1... Kf3 2.Qe3#) 2.Qe5+)
2.Qg1!

2... Kh4 3.Qh2+!

Never stop thinking when there are forcing moves left. This helps you in positions like this, if you can't spot the battery immediately!
3... Kg5 (3... Kg4 4.f3+)
4.f4+
