The event pits Valley law enforcement agencies and fire departments against each other, to see which one can bring in the most blood donors.
Dean Eller with the Central California Blood Center: "Very competitive group of people and they carry guns so it's one of those things where we really have to keep an eye on them. They are very competitive and they really turn out because they understand the need for blood.
The blood center hopes to keep its shelves full, especially with the upcoming Memorial Day weekend.
The battle of the badges ends May 21st. If you would like to help, there are three different blood center locations in Fresno.
Herndon near Milburn in Northwest Fresno
4343 W. Herndon Ave
M-TH 8a-6:30p, F 8a-6p, S 9a-3p
First and Shields in Central Fresno
3445 N. First St.
M-Th 8a-6:30p, F 8a-6p
Northeast Fresno at Champlain and Perrin
1010 E. Perrin
M-Th 8a-6:30p, F 8a-6p, S 9a-3p