We know that Surface devices provide great mobility experiences and fantastic battery life to power those experiences, even eliminating the need to carry around a charger for our latest devices with all-day battery life. We also know that not everyone uses our devices in this way. Some Surfaces are used in kiosk solutions, some are integrated into other devices, and some are just connected to docks all day long. In these scenarios, charging the battery constantly, even with the algorithmic approach we take to battery charging, can be detrimental to the device’s ability to hold a charge over the lifespan of the battery.
The new Battery Limit feature of Surface devices from Surface Pro 3 forward addresses these situations by providing a UEFI setting that instructs the battery controller to limit total charge to a maximum 50%. Enabling the setting preserves the battery’s ability to take and hold a charge while it’s connected to external power for an extended period of time and is recommended for Surface devices integrated into solutions like kiosks, consoles, and other scenarios where they are constantly connected to an external power supply.
This feature is being rolled out to devices via Firmware update. As of 10/9 Surface Pro 3 and Surface Pro 4 support this new feature after the associated firmware updates. For more information see Updates for Surface Pro 3 and Surface Pro 4 (10 September 2018).
For information on which firmware update is required and when other models will support this feature please see the KB article: KB4464941.
For full documentation of this feature see Battery Limit settings in the Surface Docs Library.