Portable power station as a UPS: router, modem and NAS picks

A winter outage is a terrible time to discover that your big battery reboots the router—or that your NAS has no idea the battery is nearly empty. Buy for transfer time, runtime and shutdown communication, in that order. A bigger watt-hour number solves only the middle one.

Specifications and transfer times below come from the makers and NUT project; runtime examples are calculated assumptions.

Quick picks: which battery fits your job?

• Best UPS-mode power station: EcoFlow RIVER 3 Max. Its RIVER 3 Plus base has a maker-rated under-10 ms transfer and a USB-B communication port. The 572 Wh package adds an EB300 battery. It is the strongest fit here for networking plus a computer or NAS, with a shutdown test as part of setup.
• Best for a router only: EcoFlow RIVER 3 230Wh. You get ordinary AC output in a smaller battery package. Its maker specifies transfer within 20 ms; run a power-loss test with your router before relying on it. EcoFlow explicitly excludes NAS and other uninterrupted computer loads from this version’s intended use.
• Best capacity: BLUETTI AC180. Its 1,152 Wh battery is the largest here. Choose it when longer runtime matters and your equipment tolerates its 20 ms transfer with Grid Enhancement off; its AC inverter’s own consumption matters at router-sized loads.
• For portable DC devices: Anker SOLIX C300 DC. This is a 288 Wh DC-only battery, with no AC outlets and no published UPS transfer figure in the maker guide we checked. Buy it for compatible USB/DC devices, not as a drop-in NAS UPS.

For a NAS-first purchase where orderly shutdown is the main goal, also read our small-rack UPS buying guide. A conventional UPS can be the better tool even when its battery is smaller.

Compare the exact versions

Model	Nominal battery	Continuous output	Maker-stated AC transfer	Shutdown communication	Best fit
EcoFlow RIVER 3 Max	572 Wh: Plus + EB300	600 W AC	Under 10 ms on the US series page	USB-B on Plus base; Power Manager; NUT lists RIVER 3 Plus	Networking plus a supported computer/NAS shutdown plan
EcoFlow RIVER 3 230	230 Wh	300 W AC	Within 20 ms; EPS	No USB UPS data interface documented in its manual	Router-only backup after transfer testing
BLUETTI AC180	1,152 Wh	1,800 W AC	At most 20 ms	No USB UPS data interface documented in its manual	Larger energy reserve for suitable loads
Anker SOLIX C300 DC, A1726	288 Wh	300 W DC total; no AC	No UPS switchover time published in its guide	USB power ports; no USB UPS monitoring feature documented	Compatible DC travel/portable backup

The EcoFlow US series page separates Max from Plus and Max Plus. Max is 286 Wh + 286 Wh = 572 Wh; Max Plus is a different package. The RIVER 3 manual also separates the 230Wh model from a distinct 10 ms UPS version. Pick by the full model name.

Use continuous output ratings for electronics. EcoFlow’s X-Boost heating-appliance claims and BLUETTI’s lifting-mode headline are not extra normal AC capacity for your NAS.

Will UPS mode switch fast enough?

Pass-through means the station can supply a load while connected to input power. Transfer time tells you how long the interruption is when that input disappears. Those are different buying questions.

The RIVER 3 Max has the best published transfer figure among these AC candidates. EcoFlow’s Plus manual describes the base unit as a standby UPS with transfer within 10 ms; its US page advertises under 10 ms. Choose it first for the UPS-mode job, then test the actual equipment.

For comparison, the line-interactive CyberPower CP1500PFCLCDa has a maker-listed typical 4 ms transfer, automatic voltage regulation and USB management. “Typical” and a maximum-style claim are different specifications, so don’t turn those numbers into an exact speed ratio. Our NAS UPS buying guide covers pure versus stepped sine, USB/NUT evidence and setup for TrueNAS, Unraid and Synology; the CyberPower specifications explain the conventional UPS option.

A router’s power brick may ride through a short gap, but the way to find out is a controlled transfer test. A NAS also needs time to stop writes and shut down. That makes communication just as important as fast switching.

Skip RIVER 3 230 for a NAS. Its manual specifically tells you not to connect NAS servers, desktops and similar devices requiring uninterrupted supply. Its 20 ms EPS feature is useful for suitable loads; it does not make it the same product as the Plus/Max.

How long will your router, ONT and NAS run?

Start with a plug-in power meter, not the power brick’s maximum label. Measure the equipment together, including any switch needed to keep it useful. For a NAS, include a busy period and drive startup in your output-capacity check.

Here is a planning worksheet with deliberately stated inputs:

• Router plus modem: 20 W combined.
• Add an optical network terminal, or ONT: 10 W, taking the total to 30 W. Include this only if your connection actually uses one alongside those devices.
• Add a mini PC: 20 W, taking the total to 50 W.
• Add a two-bay NAS: 30 W, taking the total to 80 W.

These are assumed loads, not typical-use measurements. For every AC example, assume 90% usable battery, 85% inverter efficiency and 15 W fixed station overhead. The AC180 manual uses this calculation structure, quotes about 15 W self-consumption and gives 90% depth of discharge with inverter efficiency above 85%. Applying those same values to EcoFlow is a comparison assumption, not an EcoFlow efficiency specification.

Hours = nominal Wh × 0.90 × 0.85 ÷ (load W + 15 W)

Assumed AC load	Total load	RIVER 3 230	RIVER 3 Max	AC180
Router + modem	20 W	5.0 h	12.5 h	25.2 h
Above + ONT	30 W	3.9 h	9.7 h	19.6 h
Above + mini PC	50 W	Not our computer pick	6.7 h	13.6 h
Above + two-bay NAS	80 W	Excluded by maker guidance	4.6 h	9.3 h

Treat those as scenario outputs. Actual conversion losses, reserve settings, temperature, battery age and changing loads move the result. Keep shutdown reserve rather than scheduling a NAS to run to empty. The Anker is left out because it cannot supply these AC power bricks.

The low-load trap is worth seeing: ignoring fixed overhead gives the AC180 44.1 hours at the assumed 20 W load; including the manual’s approximately 15 W consumption gives 25.2 hours. That is why “battery Wh divided by router watts” is too optimistic.

For a long outage, shut down the mini PC and NAS once their work is safe and leave the network running. Also remember that keeping your modem powered does not keep the provider’s upstream equipment powered.

Can it tell NUT to shut down your NAS?

RIVER 3 Max is the exception worth knowing about. Its Plus base has a USB-B data port, and EcoFlow documents Power Manager software for PC/NAS monitoring and automatic shutdown. Separately, NUT’s hardware compatibility list lists RIVER 3 Plus over USB with usbhid-ups.

That gives you a documented route to explore, rather than a charge-only USB socket. Use a NUT package that includes the model’s support, connect the data cable and verify that the host sees mains loss, battery state and the shutdown event. A NAS appliance’s bundled NUT version and device list can differ from the current project list.

The AC180, RIVER 3 230 and C300 DC manuals checked here do not document a USB UPS management interface. Their USB charging sockets cannot supply a battery-status signal simply because a cable fits. If automatic NAS shutdown is your priority, choose the Max’s supported communication route or a conventional managed UPS.

Our UPS sizing and graceful-shutdown guide walks through the complete dependency chain: the protected host, the controller and any networking needed to deliver the shutdown command. A battery can keep supplying power long after a host has lost the network path it needs.

Where the C300 DC makes sense

The Anker A1726 guide lists USB-C outputs and a 12 V, 10 A car socket. It suits compatible portable devices, including USB-C equipment that accepts the offered power profile. It does not accept a router’s AC power brick.

For a barrel-powered router, voltage, connector, polarity and current all have to match through a suitable regulated power arrangement. Don’t turn this purchase into an improvised cable project. An AC-output station lets you retain the equipment’s original power adapters instead.

The maker guide publishes no UPS switchover figure or seamless pass-through commitment for this DC model. It also documents low-current USB auto-off behavior after two hours. Choose it as portable backup, and choose one of the AC UPS-mode options when automatic changeover is the job.

Set it up before the first storm

For off-grid texts, choose a battery-powered Meshtastic starter node and test messages with a second node before the next outage.

1. Choose the protected load. Keep the list short: internet equipment first, then a host or NAS with a clear shutdown job. Measure watts and use the sizing guide for W/VA headroom.
2. Give the station ventilation. Follow its manual’s placement and charging instructions; keep intake and exhaust clear.
3. Set UPS and low-load options. On AC180, turn Grid Enhancement off in the BLUETTI app: the manual’s page 13 says it lengthens switchover when enabled. Disable AC ECO auto-off for an always-on small load too. On EcoFlow RIVER 3 230 and the Plus base in Max, set AC timeout to Never in the EcoFlow app so an idle outlet stays on.
4. Connect shutdown data where supported. On Max, use the Plus base’s USB-B communication port, then configure and verify the software on the actual protected host.
5. Test a mains failure. Follow the maker’s outage-test procedure with nonessential workloads first. Watch whether the router reboots, the host reports battery operation and the NAS completes an orderly shutdown with charge remaining.
6. Test recovery too. Restore input power and observe charging, outlet state and host restart behavior. Write down what needs a button press so the next outage has fewer surprises.

Buy RIVER 3 Max for the most complete UPS-mode package here, RIVER 3 230 for suitable router-only duty, or AC180 for the larger energy reserve. Keep C300 DC on the portable-DC shortlist. For a NAS whose main job is surviving a brief interruption and shutting down cleanly, start with the conventional UPS guide and let the shutdown plan decide.

For a router and ONT that can use DC backup directly, our DC mini UPS guide walks through voltage range, polarity, plug fit and runtime estimates before you choose a pack.