Electronic shifting requires a power source that delivers consistent voltage while fitting into tight frame spaces. The Campagnolo EPS V4 Power Unit combines a three-cell lithium-ion battery pack with Digital Tech Intelligence circuitry in a sealed housing that measures 259mm long and 16.6mm in diameter. The slender profile solves the fitment problems that plagued earlier power units, particularly with smaller seatpost diameters and internal cable routing configurations. The compact dimensions allow installation inside most seatposts using included adaptors for 27.2mm or 31.6mm diameters, or you can mount the unit externally to the seat tube or down tube using water bottle cage bosses when internal installation isn't feasible.

The V4 version increases battery capacity by ten percent compared to the previous generation, extending the range to approximately 1700 kilometers on a full charge. That's enough for multiple weeks of training and racing before you need to find an outlet. Even when the battery drops to 25 percent capacity, you still get roughly 400 kilometers of shifting before needing to recharge, which provides a comfortable safety margin for long rides. The battery uses a twelve-volt configuration that delivers stable power to the derailleurs regardless of temperature or terrain. Lab testing confirms the battery maintains performance through more than 500 charge cycles, which translates to years of use before any degradation in capacity or output.

The Digital Tech Intelligence system functions as the brain of the EPS drivetrain, processing data thousands of times per second to coordinate shifting commands between the levers and derailleurs. The DTI monitors battery charge levels, tracks derailleur position and functionality, and runs continuous diagnostics on the entire system. An RGB LED built into the power unit provides color-coded feedback about system status and alerts you to potential issues before they affect performance. The on-board diagnostic capability identifies specific problems by changing the LED color, helping you troubleshoot without specialized equipment.... Read More