The Deck has a theoretical maximum of 8 hours at the battery’s peak capacity if all components are using minimum power draw. Real world battery life is around 90 minutes in max workloads (e.g. playing Cyberpunk) and 2~4 hours in most workloads. You can manually limit TDP and clamp clock speeds on CPU/GPU to extend battery life upwards of 5~6 hours in retro 2D games.