EcoFlow Rapid Series 20K Battery Pack Review: Great Pocket Power, With Some Rough Edges

5 min readEcoFlow isn’t exactly a huge name in the battery pack space, which is dominated by tech-adjacent brands like Anker and Mophie. If you’ve ever looked into larger backup power solutions—specifically portable power stations or solar generators for camping, an RV, to back up home appliances in an emergency–the brand name carries a lot more weight. For many years, EcoFlow’s backup power solutions have earned recommendations from my colleagues.So I was intrigued when I learned that the brand had entered the smaller, EDC-friendly world of portable power banks. EcoFlow isn’t the first to make the transition; BioLite has been making battery packs for some time, some of which are impressively effective and feature-rich. I was similarly surprised and delighted by my EcoFlow pack, the 20,000-milliampere-hour (mAh) Rapid Series charger, a midsize battery pack with above-average specs and a sub-$50 price tag. While I found a couple of minor flaws that might point to how and why it’s so cheap, it’s still a rare bargain if you’re looking for the biggest possible pack that might conceivably fit in your pocket.ProsHigh capacity and charging rate for priceCan charge some larger devicesLED battery life indicatorConsExterior scratches easilyA little too big your pocketKey SpecsBattery Capacity20,000 mAhPower Output45W (single output) / 45W (total output)ConnectivityUSB-C cable, USB-C port, USB-A portWeight13.2 ozA Tweener, Twofer Sort of Battery PackBattery packs come in a wide range of shapes and sizes, with an even wider range of battery capacities and charging speeds. But they broadly fall into two categories: smaller, pocket-sized models made to keep your phone and other small everyday tech charged, and larger laptop chargers made to back up your PC, a pro-grade digital camera, and other, more power-hungry gear.The Rapid 20K 45-watt (45W) fallss somewhere in the middle. It has the capacity to recharge most phones somewhere between three and four times to 100 percent capacity. (Expect it to be closer to three if you’re using a flagship-tier like the iPhone 17 Pro, which was my primary test device.) And with 45W out of a single USB-C cable, you can charge a lightweight productivity laptop in a pinch, albeit slowly. That’s more than you can expect from pretty much any lightweight battery pack, which usually fall between 5,000 and 10,000 mAh and tend to max out at 30W or less.Mike EpsteinThe display shows remaining battery percentage, which I prefer to light-up dots.Compared to purpose-made laptop-grade battery packs, the Rapid 20K is small and lightweight. It weighs just over 13 ounces and measures 2.5 by 6 by 0.75 inches (W x H x D). It’s actually close in size to my phone, and it creates a similar bulge in the front pocket of my jeans if I carry it that way.Personally, I’m more inclined to carry it in my backpack: That’s in part because I always stash a battery pack in my bag for work emergencies, but also because it does get a little tight in there when you put the pack and the phone in the same pocket. I’ve done it and it’s not unbearable, but I wouldn’t say it’s comfortable, either.And that’s indicative of the double-edged nature of this pack’s form factor. On the one hand, you’re getting way more power than you would from most pocket-sized packs, which is great if you know you’re going to be away from power for a long time. On the other hand, that higher capacity and charging rate fall short of the best laptop chargers, which generally have the ability to match the speed of a laptop’s charging cable.Given that, I think most folks will be better served considering this pack an XL phone charger, rather than a mini laptop charger. If you use your battery pack to charge a laptop often, I’d still size up.Big Pack, But Single-Device FocusedThe Rapid 20K’s port lineup also falls in line with smaller battery packs. Its primary output is a 10-inch, 45W braided USB-C cable that doubles as a carrying strap–the head of the cable slides back into a small housing at the base of the cable to make a loop. It also features a 45W USB-C input/output port for charging and a less powerful 22.5W USB-A port.Mike EpsteinThe integrated cable, USB-A port, and USB-C port offer a decent range of connection options.Since the device’s single-device and total charging rates are both 45W, you will experience a pretty substantial slowdown if you plug in multiple devices at once. That’s par for the course, I’m afraid, though some battery packs will build in extra capacity to support multi-device charging. That is, again, something you’re more likely to find in a larger laptop charger than a compact device. (Though it has been done.)A Sleek VeneerZooming out for a second, the EcoFlow looks pretty sleek. Its matte silver anodized aluminum alloy chassis conjures thoughts of a MacBook. A black plastic rim on one end indicates where the ports are at a glance and hides a small LED battery life indicator with a percentage readout, rather than the usual (and frustratingly vague) light pips.While I love the look, I was disappointed to find the silver finish on the body is extremely sensitive to scratches. After a few weeks in my bag, one side of the pack is scuffed and scratched. I shudder to think what it would look like if it shared a pocket with my keys for a week.To be clear, that doesn’t make it any less durable than other battery packs; it's just probably going to look weathered before too long. If you like a little patina on your tech, this might even be a bonus for you. But most tech folks I know would rather keep their gear looking fresh, so I’d say buyer beware.Who Should Buy the EcoFlow Rapid Series 20K Battery Pack?The EcoFlow Rapid 20K 45W is a rare value. Thinking purely in terms of capacity for your price, you aren’t going to find something much better than this. And, similarly, its size and shape are pretty comfortable to carry around, especially for commuters who carry a bag.That said, it is realistically more battery than most people need on a daily basis–most modern phones, earbuds, and small EDC tech can make it through a day without charging, so a very small 5,000-mAh pack like the lipstick-sized mophie PowerStation Mini 5K is usually enough to keep people topped off. Those of us who work our tech hard and need to stay powered up over long flights, long days at a job site, or multiday camping trips are far more likely to push this gear to its limits.In many cases, those folks are better served spending more to buy a more powerful laptop charger, like our current top recommendation, Anker’s 25K, 165W laptop charger. However, for less than $50, the EcoFlow Rapid is a very appealing budget-friendly alternative, especially if you’re mostly charging phones and tablets, rather than laptops and cameras.Shop the EcoFlow Rapid Series 20K 45W Battery PackMore Battery Packs We LoveElecom Nestout 15K Rugged Battery Packmophie Powerstation Mini 5K Battery PackAnker Anker Prime 9,600mAh Battery PackNow 22% OffMike Epstein is a Senior Commerce Editor at Hearst Enthusiast Group, producing reviews for buying guides Popular Mechanics, Runner’s World, Bicycling, and Best Products. Prior to joining Hearst, he was a video game and technology critic for over 10 years, with bylines at IGN, Gamespot, Variety, Lifehacker, Kotaku, GamesRadar, Flavorwire and Digital Trends, among others. Now, he’s a jack of all trades, helping reviewers share everything they know about all kinds of technical gear, from snowblowers, to running shoes and bicycles, and every kind of gadget imaginable.Will Egensteiner has been reviewing products for 10 years, testing and writing about everything from climbing gear to video game consoles to cars. He began his career as an intern at Popular Mechanics, then worked as an editor at Outside, spearheading the magazine's gear coverage and biannual Buyer's Guide. Now that he's back, he leads product reviews for PopMech, as well as Runner's World, Best Products, and Biography. His favorite stuff to review is still outdoors equipment, and he can tell you from memory what ePTFE stands for.