86: A Hard Cell: Engineering Ultra-Narrow Batteries for AI Glasses

Your smart glasses run all day on a battery narrower than your pinky finger and building it required reinventing how batteries are made. In this episode, Pascal talks to Karthik and Myuran, the engineers behind Meta's steel can battery technology, to explore why traditional pouch cells couldn't cut it for the ultra-slim temple arms of AI glasses like Meta Ray-Bans and the Oakley Vanguards. Tune in to learn how Meta designed, built, and scaled the batteries powering your glasses, wristbands, and cases from first prototype to mass production. Got feedback? Send it to us on Threads (https://threads.net/@metatechpod), Instagram (https://instagram.com/metatechpod) and don't forget to follow our host Pascal (https://mastodon.social/@passy, https://threads.net/@passy_). Fancy working with us? Check out https://www.metacareers.com/. Links SilverTorch: Index as Model — A New Retrieval Paradigm for Recommendation Systems - https://engineering.fb.com/2026/05/26/ml-applications/silvertorch-index-as-model-new-retrieval-paradigm-recommendation-systems/ Timestamps Intro and News 0:06 Guest intros 1:49 The problem with existing batteries 4:16 Pouch vs Steel Can Batteries 6:40 What does lower impedence mean? 10:27 Power requirements 12:25 Synchronising two batteries 16:02 Manufacturing never-done-before batteries 23:11 Software vs hardware iteration cycles 28:12 Collaborations across the globe 30:51 Market compliance 37:00 Outro 42:24