Anker 521 vs EcoFlow RIVER 2: Which 256Wh Portable Power Station Fits You?

Buy Anker 521

Buy EcoFlow RIVER 2

TL;DR:

Fastest charging & higher AC headroom: EcoFlow RIVER 2 (256Wh, 300W AC / 600W surge, 0–100% in ~60 mins).
Long-life LFP + great value, but lower AC ceiling (US models): Anker 521 (256Wh, ~200W AC continuous, SurgePad up to 600W depending on region).
For laptops/cameras/CPAP up to ~200W? Anker 521 is fine. Need 250–300W AC for small appliances? RIVER 2 is the safer pick.

Quick Comparison Table

Feature

Anker 521 (PowerHouse 256Wh)

EcoFlow RIVER 2 (256Wh)

Battery Capacity

256Wh

Battery Chemistry

LiFePO₄

AC Output

~200W (US listing), SurgePad up to 600W on some regional pages

300W (600W surge)

Charging Speed (AC)

USB-C/DC inputs (not 1-hour full AC fast charge)

0–100% ≈ 60 minutes via X-Stream

Solar Input

DC 11–28V up to ~65W (via 7909)

Up to 110W solar (EcoFlow spec)

Weight

~8.2 lbs (varies by listing)

~7.7 lbs (3.5 kg)

App control

No dedicated app

EcoFlow app (Bluetooth/Wi-Fi)

Warranty

Often 5-year device warranty; 10-year lifespan claim

Up to 5-year warranty (region-dependent)

Current Price

Note on Anker 521 wattage: Anker’s own pages list the 521 as 256Wh | 200W for the US lineup; some EU pages show 300W with SurgePad to 600W. Check your region/label on the unit for the exact AC rating.

Who Each One Is Best For

Choose Anker 521

if you mostly power phones, cameras, drones, LED lights, laptops and want a value LFP pack with a long service life, and your AC loads are typically <200W.

Choose RIVER 2

if you want faster top-ups (≈1 hour) and 300W AC headroom for things like a small blender, projector, mini fan, or modem/router setups, plus app control.

Head-to-Head Comparison

Battery Capacity & Chemistry

Both use LiFePO₄ and emphasize long cycle life (often marketed around 3,000 cycles to 80% in this class).

Anker promotes a 10-year lifespan and 5-year warranty for 521; EcoFlow lists 3,000 cycles and strong warranty coverage as well.

Winner: Tie on chemistry; warranty and cycle messaging are strong on both.

AC Output & Power Capabilities

Anker 521: US lineup typically 200W continuous (SurgePad can momentarily bump supported loads). Good for laptops, cameras, routers, CPAP under ~200W.

RIVER 2: 300W continuous (600W surge); better for small appliances that spike above 200W.

Winner: RIVER 2 for flexibility if you flirt with 250–300W.

Charging Speed

Anker 521: Solid recharge options via DC/USB-C, but not a 1-hour wall blitz on official pages.

RIVER 2: 0–100% ≈ 60 minutes via AC. This is class-leading at this size.

Winner: RIVER 2 by a mile if you need fast turnarounds.

Solar Input

Anker 521: DC 11–28V (≈65W max) via 7909 connector; pairs well with a 60–100W panel.

RIVER 2: Up to 110W solar input; quicker solar top-offs in good sun.

Winner: RIVER 2 for higher solar intake.

Portability & Noise

Anker 521: Around 8.2 lbs; quiet operation, integrated LED on some variants.

RIVER 2: ~7.7 lbs (3.5 kg); fans can be audible under load, per reviews, but overall very portable.

Winner: RIVER 2 is slightly lighter; Anker also travels well.

App & Smart Features

Anker 521: No dedicated mobile app control.

RIVER 2: EcoFlow app (Bluetooth/Wi-Fi) for firmware, charge rate, and output control.

Winner: RIVER 2.

Use-Case Scenarios

Weekend photo/video shoot (laptops + camera batteries)

Either works; if you need to run a 150–200W light reliably, the RIVER 2 gives more cushion.

Emergency router + phones + LED lights during an outage

Both fit; RIVER 2 recharges from wall fast between rolling outages.

Camping fans/projector/cooler under 300W

RIVER 2 is safer due to AC headroom.

Budget-minded everyday gadget charging

Anker 521 often comes in at a better price-to-Wh with long warranty.

Final Verdict

Pick the Anker 521 if your loads are ≤200W and you want a value LFP station with a long warranty for daily charging and light emergency use.
Pick the RIVER 2 if you want the fastest wall recharge (≈60 mins), app control, and 300W AC headroom for small appliances.