BTI Battery for Microsoft Surface Book 13.5" (CR7/CR7-0000) — 7.5V 2387mAhThe BTI Battery is a reliable, rechargeable power solution designed specifically for notebooks that require a proprietary battery size. With a precise 7. 5V DC output and a capacity of 2387 mAh, this replacement battery delivers a steady, uninterrupted energy supply to help you stay productive, even on the busiest days. Built to fit select notebook models through its proprietary sizing, it anchors securely in place, reducing connection issues and