Frag Grenade

A hand grenade is a small, light-weight, timed explosive device.

Battlefield: Bad Company
In Bad Company, hand grenades are given to the Assault, Specialist and Demolition kits. It is a secondary weapon, so one must switch to it and then throw it. It inflicts high damage to infantry, often killing with a single grenade, but has relatively not effect to vehicles.

Each kit has a maximum of 5 grenades.

Battlefield 1943
In Battlefield 1943, hand grenades are given to the Rifleman and Infantry kits of the IJN (Type 97 variant) and the USMC (MK2 variant). There performance is exactly the same as in Bad Company only the player isn't obligated to witch to them.

Each kit has a maximum of 2 grenades (once all used, the amount "regenerates").

Battlefield: Bad Company 2
Hand grenades perform exactly as they do in Battlefield 1943, but return with Bad Company's appearance.

Trivia

 * With the Frostbite engine, grenades can cause slight ground deformation and destruction to light environment.