EcoFlow shrinks its portable power stations with new River Gen4 models

Both models use LFP battery chemistry with a longer lifespan and lower volatility. The River 260 Gen4 stores 256 Wh and the River 520 Gen4 stores 512 Wh, roughly 2.5 times and 5 times the energy allowed in the largest airline-approved portable chargers. The smaller model offers four USB ports and a single AC outlet with 300 W of continuous output; the larger one has four USB ports and two AC outlets for 500 W.

Thanks to class-leading energy density, the units weigh less and take up less space than similarly equipped rivals, making them suitable for overnight camping trips or field photo shoots. The 520 Gen4 can run a standard U.S. refrigerator for about four hours during an outage.

In terms of volume, the River 520 Gen4 measures 5.63 liters and weighs 4.6 kg, giving it a volumetric energy density of 90.9 Wh/L, while comparable units like the EcoFlow River 2 Max, Anker 535 and Bluetti AC50B are all above 12 liters and hover near 37 Wh/L, according to figures cited by The Verge. The River 260 Gen4, at 4.30 liters and 3.0 kg, achieves 59.5 Wh/L, compared with 34.4 Wh/L for the previous River 2 and around 32–45 Wh/L for the Anker Solix C300 and Bluetti EB3A.

Both models can also serve as a UPS for a computer, with a cutover time below 10 ms. They include one bidirectional 140 W USB-C PD3.1 port, allowing direct DC charging from a 140 W USB-C wall charger or a portable USB-C solar panel, eliminating the need for a dedicated power brick.

EcoFlow said it lowered the energy lost converting stored DC to AC, leaving more watt-hours for charging phones, drones, bike computers or powering a Starlink Mini and a small fridge.

The River 260 Gen4 will go on sale in Europe in the fourth quarter of 2026, and the River 520 Gen4 is expected in the first quarter of 2027. Pricing will be announced closer to the release dates.