The Electronic Battering Ram is a device used by S.H.I.E.L.D. to breach locations and vehicles. It was used to smash the driver's window of Nick Fury's SUV during HYDRA's Attack on Nick Fury, and to get inside the Retreat during the Ambush at the Retreat.
Unable to kill Nick Fury due to the robust armor of his SUV, a team of HYDRA operatives, disguised as Washington, D.C. Metropolitan police officers and SWAT team members, resorted to using the Electronic Battering Ram to smash the driver's window of the car. 
In order to restrain Phil Coulson and Lance Hunter, S.H.I.E.L.D. agents sent by Robert Gonzales had to enter the Retreat. With the building locked down, the agents used an Electronic Battering Ram to breach the facility, and entered the building.
Restraining Calvin Zabo
At the Playground, Calvin Zabo's heart stopped beating due to the drugs he took. Unbeknownst to the agents stationed at the Playground, the drugs were the last ingredient to his formula. This formula caused him to wake up with superhuman strength and in an extremely agitated state of mind. Zabo, fueled by his anger towards Coulson, started to rampage within the base. At the hanger, Coulson was finally able to calm him down after he used an Electronic Battering Ram to reinforce the S.H.I.E.L.D. SUV pinning him to a wall. This bought Coulson time to convince Zabo of his wife Jiaying's insanity. When he asked Zabo if he was willing to protect Skye from her mother, Zabo grew angry enough to push away both the SUV and Electronic Battering Ram and free himself.