EcoFlow has unveiled the fourth generation of its River series of portable power stations, which are smaller and more energy-efficient than earlier versions. These devices are designed to provide reliable power for outdoor activities, emergency situations, or as backup power during outages. The new River 260 Gen4 has a battery capacity of 256 watt-hours (Wh), and the larger River 520 Gen4 offers 512Wh. These capacities are about 2.5 and 5 times greater, respectively, than the largest airline-approved portable power banks. Both models use lithium iron phosphate (LFP) batteries, which are known for being safer and longer-lasting compared to other battery chemistries. The River 260 Gen4 includes four USB ports and can deliver up to 300 watts of continuous power through a single AC outlet. The River 520 Gen4 offers the same USB ports but has two AC outlets capable of providing up to 500 watts of continuous output. Both models are praised for their high energy density, which means they store more energy in a smaller and lighter package compared to similar products. This makes them ideal for use during camping trips or in the field where space and weight are important factors. In terms of performance, the River 520 Gen4 has a volumetric energy density of 90.9 Wh/L, which is significantly higher than other models like the EcoFlow River 2 Max, Anker 535, and Bluetti AC50B. The River 260 Gen4 also performs better than its predecessors and competitors, with a volumetric energy density of 59.5 Wh/L. These figures indicate how efficiently each model stores energy in relation to its size. Both the River 260 and 520 Gen4 models can function as a backup power supply (UPS) for computers, with a seamless switch to power in under 10 milliseconds. They also feature a high-capacity 140W USB-C PD3.1 port that supports both charging and discharging, enabling the use of a high-power wall charger or a solar panel for direct charging. EcoFlow has also improved efficiency by reducing the amount of energy lost during the conversion from direct current (DC) to alternating current (AC), helping to preserve more usable power for connected devices. The River 260 Gen4 is expected to be available in Europe during the fourth quarter of 2026, while the River 520 Gen4 is set to launch sometime in the first quarter of 2027. Specific pricing details for both models will be announced closer to their global release dates.