Skip to main content

Valve Extends Battery Life With Third Evolution of Knuckles VR Controllers

In late June, shortly after E3, Valve released details about a revised version of the company’s in-development next-generation VR controller, the Knuckles EV2. The EV2 was a major step forward from the original prototype design, but Valve and the developers who received EV2 controllers weren’t completely satisfied with the design, so they redesigned it again. Valve’s latest iteration, the Knuckles EV3, offers stronger components for better reliability, improved battery life for extended play time and a refined strap to better hold the controller in the palm of your hand.

Valve teased developers at the 2016 Steam Dev Days conference with the next generation of the Steam VR controller. The company showed off a working prototype of the Knuckles controller that lets players use their fingers for gestures and input without pressing buttons. The controllers included a strap that holds the controller in your palm even when you lift all your fingers off it. Valve promised that the Knuckles controllers would unlock new ways to interact with VR experiences and quickly put the controllers in the hands of a select group of developers. We thought we would see the controller hit the market before the end of 2017, but we should have expected delays. Valve operates on Valve-time even when it develops hardware.

In June, Valve revealed the Knuckles EV2 controller, which improved upon the original design in several ways, including a more ergonomic shape, improved hand strap that accommodates larger and smaller hands than the original prototype. The controller also includes analog force sensors coupled with capacitive touch sensors for all five digits.

Now, Valve is offering further refined controllers to select developers in Knuckles EV3. 

Ergonomic and Reliability Improvements

The Knuckles EV3 controllers aren’t dramatically different than the previous iteration, but they improve upon several features, and Valve claims they offer better fit and finish than the older revision.

The new controller includes strap adjustment markings to make it easier to set the size correctly. Valve’s designers also shortened the drawstring and decoupled the strap from the wing plate, which wraps around your hand. It also appears Valve is using a softer fabric for the new strap design.

Valve also adjusted the buttons on the new Knuckles controller. The designers recessed the system button to minimize unintended presses, reinforced the trigger assembly and installed a higher tension spring to improve the reliability of the trigger button. Valve also said the EV3 controller includes grip sensors that are “more reliable from unit to unit,” which could suggest that the sensors in the EV2 controllers are prone to failure. The new controller design also features a recessed USB charge port and a new LED to indicate the controller status.

Battery life is perhaps the most notable change between the EV2 and EV3 Knuckles controllers. The previous iteration featured a 900mAh battery, which provided up to six hours of continuous use, a downgrade from the Vive wands’ eight hours of run time. Valve didn’t upgrade the battery capacity, but the new controllers feature high-efficiency sensors, which extends the run time by up to two hours. Valve said gamers could expect seven to eight hours of use between charges.  

Wider Distribution

Valve first teased developers with Knuckles controllers two years ago, but to-date, only a few select developers have access. That’s about to change.

Valve said that it would produce “much greater quantities” of Knuckles EV3 controllers compared to past versions and offer controllers to a wider selection of developers. It will send EV3 controllers to existing Knuckles-approved developers and will reach out to developers who previously requested Knuckles controllers but didn’t make the early list. The company also plans to open requests again soon and encouraged developers to keep an eye on the Steamworks partner website.

More Development Resources

In addition to providing developers with a new version of the Knuckles controllers, Valve also released more resources to help developers get started. The company updated the Moondust demo to support Valve’s customizable SteamVR Input system, the SteamVR Interaction System and SteamVR Skeletal Input. Valve also released the source code for the Knuckles Tech Demos, so developers can learn how Valve built them, and an updated version of the SteamVR Interaction System Unity plugin, which supports the new controllers and all their features.