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I found the Goldilocks of portable power stations, and I take it on all my adventures

Looking to harvest free power for your off-grid adventures? Check out the EcoFlow River 2 Max, a portable, highly durable power station with plenty of juice.
Written by Adrian Kingsley-Hughes, Senior Contributing Editor
EcoFlow River 2 Max

EcoFlow River 2 Max.

Adrian Kingsley-Hughes/ZDNET

I love power stations. They're the off-grid adventurer's answer to the power bank. They're a huge box of batteries that can be used to charge USB devices and run gadgets that need AC power.

But power stations can be big, weighty things. That's fine if you have a vehicle to haul your gear to your destination, but if you're going on foot, most power stations are just too heavy to lug about.

Also: The best portable power stations you can buy: Expert tested

And most of those that are small enough to carry are too small to be useful.

The EcoFlow River 2 Max sits in the middle -- compact enough to be portable, big enough to be practical. 

View at Amazon

EcoFlow River 2 Max tech specs

  • Capacity: 512Wh
  • Net Weight: 13.4lbs
  • Dimensions: 10.6 x 10.2 x 7.7 inches
  • Cell Chemistry: LFP (lithium iron phosphate)
  • Cycle Life: 80%+ capacity after 3,000 cycles
  • AC Input: 100-120V, 50Hz/60Hz, 660W Max
  • Solar Input: 11-50V, 13A, 220W Max
  • Car Input: 12V/24V, 8A, 100W Max
  • USB-C Input/Output: 5/9/12/15/20V, 5A, 100W Max
  • AC Output: 120V, 50Hz/60Hz, 500W (Surge 1000W)
  • DC Output: 12.6V, 10A/3A/3A, 126W Max
  • USB-A Output: 5V, 2.4A, 12W Max
  • DC5521 Output: 12.6V, 3A, 36W Max
  • App Control: Wi-Fi, Bluetooth
  • Discharge Temperature: 14°F to 113°F/-10°C to 45°C
  • Charge Temperature: 32°F to 113°F/0°C to 45°C
  • Optimal Operating Temperature: 68°F to 86°F/20°C to 30°C
  • Storage Temperature: 14°F to 113°F (68°F to 86°F is best)/-10°C to 45°C (20°C to 30°C is best) 

Note that the version I'm testing is the variant aimed at the UK market, so it has different AC outlets and power inputs/outputs, but beyond that the unit is the same as the US variant.

Also: This $25 'solar cockroach' DIY kit is fun for the whole family

I've previously tested the River 2 Max's smaller sibling, the River 2, which weighs in at 7.7 pounds, has a power capacity of 256Wh, and capable of a sustained AC output of 300W (600W max). That smaller power station is perfect for times when you want to take power outdoors, but you don't need too much of it.

The handle is comfortable, even for extended periods of carrying the power station

The handle is comfortable, even for extended periods of carrying the power station.

Adrian Kingsley-Hughes/ZDNET

The River 2 Max takes things to the next level. The capacity is doubled to 512Wh, the weight bumped up to 13.4 pounds, and it is capable of a sustained AC output of 500W (1,000W max). While 13.4 pounds is hefty, it's some 22% lighter than the previous generation EcoFlow units of comparable specs.

Getting 124W of free electricity from that solar panel

All the ports you need -- USB-A and USB-C, AC, and DC.

Adrian Kingsley-Hughes/ZDNET

You can recharge the River 2 Max using one of four methods -- AC, solar, 12V in-car, and USB-C. If you choose AC, the unit can go from zero to 100% in an hour, which means you can leave charging to the last minute.

Also: I tested the world's smallest power station, and it's a solar-charging beast

If you want to go totally off-grid, EcoFlow offers a 160W solar panel that can recharge the River 2 Max in about four hours. The panel is durable and waterproof to IP68, so it's the perfect adventure companion for the River 2 Max.

EcoFlow River 2 Max with 160W solar panel

EcoFlow River 2 Max with 160W solar panel.

Adrian Kingsley-Hughes/ZDNET

The solar panel adds weight and bulk, but it transforms the River 2 Max into a totally off-grid solution.

Also: Why you need a batteryless jump starter (and how it works)

And it works really well. I've tested this in the UK in May and could get 125W out of the panel with it placed flat on a roof and a hazy sun, which is excellent performance.

Getting 124W of free electricity from that solar panel

Getting 124W of free electricity from that solar panel.

Adrian Kingsley-Hughes/ZDNET

You might be worried that all the charging and discharging is going to wear out the River 2 Max, but you shouldn't be. 

If you were to completely charge and discharge the River 2 Max six times a week, EcoFlow claims the lithium iron phosphate batteries would last for 9.6 years before their capacity drops to 80%.

Also: I found a Qi2 charging station that can do it all (and Apple users will love it)

A built-in fan kicks in and keeps the batteries cool when charging and discharging at high wattages. The fan generates a maximum of 62db of noise, which is the sort of sound level you'd get from a household dishwasher. I've had this power station running next to my head and I didn't find the noise all that noticeable.

If you don't want to spend your time jabbing buttons then the River 2 Max can be controlled remotely using the EcoFlow App. Keep an eye on charging levels, tweak settings, and adjust charging speeds, all from your iPhone or Android smartphone.

Inputs on the back of the unit for AC power and solar

Inputs on the back of the unit for AC power and solar.

Adrian Kingsley-Hughes/ZDNET

The River 2 Max can also be used as a backup device for when the power goes out. It can detect the mains power is down and switch over to the battery in 30ms, which means that connected devices will keep on running as though nothing has happened.

Also: Turn off this default power setting now

Some context: a typical Wi-Fi router draws about 10W, which means this unit can keep the router going for about 16 hours.

The optional 160W solar panel turns this into a truly off-grid power station

The optional 160W solar panel turns this unit into a truly off-grid power station.

Adrian Kingsley-Hughes/ZDNET

The unit is rugged and well built and shrugs off the knocks and bumps that it will inevitably get when being used.

Currently available for $499, the EcoFlow River 2 Max is competitively priced and is highly recommended for those looking for a truly portable power solution. I plan on taking this on more adventures real soon.

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