Humanoid robots, modelled on the human form, offer potentially huge economic benefits for manufacturers and society, but their revolution needs to be powered, and selecting the right battery will be key to enabling greater autonomy and supporting market adoption. Batteries are the most suitable power supply thanks to their relatively high energy density, the variety of chemistries available, and their compact nature. Manufacturers on the market include Tesla, Figure AI and Agility Robots. IDTechEx's new report "Batteries for Humanoid Robots 2027-2037: Technologies, Players and Forecasts" outlines the key battery technologies being adopted and the significant battery demand they are expected to generate, reaching 10.5 GWh by 2037. Productivity gains are driving production, with humanoid robots addressing labor shortages in physically demanding jobs such as heavy manufacturing or care-homes, and developers such as Tesla using production to diversify their product portfolio while leveraging expertise in AI, manufacturing and batteries. The battery must power all on-board components for as long as possible, making energy density and operational time key metrics, since heavy lifting and walking require sufficient stored energy to complete movement without requiring charging soon afterwards.