One of the key factors for extended autonomy and resilience of battery-powered multirobot systems is their ability to maintain energy sufficiency by recharging when needed. In situations with limited access to charging facilities, robots need to be able to share and coordinate recharging activities, with guarantees that no robot will run out of energy. In this work, we present an approach based on control barrier functions (CBFs) to enforce both energy sufficiency (ensuring that no robot runs out of battery) and coordination constraints (guaranteeing mutual exclusive use of an available charging station) in a mission agnostic fashion. Moreover, we investigate the system capacity in terms of the relation between individual robot properties and the limit on temporal separation requirements within charging cycles. We show physics-based simulation results as well as real robot experiments that demonstrate the effectiveness of the proposed approach.