This thesis conducts research into different rechargeable battery technologies and their applicability to the high altitude balloon flights conducted at Esrange space center. The research focuses on the possible use of lithium ion batteries’, sodium ion batteries, nickel metal hydrate, and Metal hydridelithiumion batteries. Resulting in lithium ion batteries in 18650 cells being recommended. The thesis continues with a modular power distribution system architecture design. The system architecture is established with solarcharging capabilities, up to 1500W peak output power, over 600W continuous output power, multiple output voltages, more than six output channels, remote output power switching, and monitoring of power consumption. A prototype is built from this architecture on which limited testing is performed.The testing shines light on future improvements and displays proof of concept for some parts.