Speaking of that wall plug, it's the most useful feature ever on a power bank. Some power banks come with a built in USB-C cord, but this Anker comes with a two-prong power outlet plug. That makes it a wall charger as well as a power bank, and the utility can't be understated. You don't need all those extras: The Anker Prime power bank is pricey, and if you don't care about monitoring charge Wattage or days of battery life, find another option. To test charging times and claims, we charged a Samsung Galaxy S23 Ultra and an Apple iPhone 15 to determine how many charges each battery offers these devices. We chose a common smaller battery phone as well as our best phone overall for this purpose. The most important question to consider when buying a power bank is what will you be charging? If you are charging a small smartphone and that's all, a simple power bank will suffice. If you plan on charging a laptop occasionally as well, or many devices at once, you'll want something with more power and more features. You can buy the Tylt Bottle with just a power bank attached, but our review sample from AT&T had the full wireless charging treatment. It's easy to set up a phone to charge while studying, working out, or working away from home: all places we take a water bottle and need a full phone battery.

There are plenty of other power bank makers around, and most of them have not caught up to the faster charging speeds available on the iPhone 15 family, let along even faster Android phones. Except for unique form factors or serious bargains, we stayed away from recommending power banks from reputable makers if they couldn't charge at 2023 speeds.

CHARGING FOR 2

Our favorite power bank has a 10,000mAh battery, and the Samsung Galaxy S23 Ultra has a 5,000mAh battery, so the math should be simple, right? It charges twice. Except that's not how it works. Power banks are not 100% efficient, and even though you start with plenty of power, a lot of it is lost in the charging process. If you have a newer Android phone, or the latest iPhone 15 models, you'll want a power bank with faster charging speeds to get your battery full faster. Charging speed is measured in wattage, and the iPhone 15 can charge just a bit faster than 15W, while the Galaxy S23 Ultra can charge up to 45W. Using the Anker Prime power bank, we were also able to test the charging speed claims of other power banks, as the Anker Prime will report charging speed in wattage.

That app is essential because there's a Find My feature built into the battery. It doesn't work like an AirTag over UWB, it's only Bluetooth, but it's useful if you misplace your battery in your office (or you have multiple batteries, like I do).We wish there wasn't such an easy answer to this question, because competition is better for everybody, but Anker is making the best power banks right now by far. It offers the best power-to-weight ratio, the fastest charging, and the most useful features. There are plenty of combination power bank and some other device, but the Tylt Bottle 2 actually makes sense because we're usually carrying an insulated water bottle anyway, so we might as well screw a battery onto the bottom. With a 5,700mAh capacity, the Tylt Bottle 2 is just enough to get us through a very busy day, or keep the phone powered while we play games at the cafe. Anker batteries also look great and are built with high quality parts. The display on our best battery for power users is bright and sharp OLED display, totally unnecessary for a power bank, but that's what makes Anker the best. It far exceeds our expectations of what's necessary to make power banks that are great.

You need fast power: This is a very slow charger, whether wired or wireless, so it's better for casual charging while you sip your water and read a book. You need a lot of power: Thankfully, the battery on the Tylt Bottle 2 isn't so big it adds too much weight, but that also means it isn't powerful enough for multiple charges. We have tested the best power banks by using them to charge a variety of devices, including Apple iPhone, Google Pixel, and Samsung Galaxy phones. We have also charged Apple iPad tablets, and small laptops including a Pixelbook Go and a Surface Laptop Go. The Anker Prime series of Power Banks, including the Anker Prime 27,650mAh Power Bank (250W) and the Anker Prime 20,000mAh Power Bank (200W), are for people who truly love to geek out on power banks. If you came looking for the absolute best power bank you can buy, this is the best we've tried.The Anker Nano is only 5,000mAh, but that doesn't mean it can fully charge a 5,000mAh phone battery like you'll find in the Galaxy S23 Ultra. Power banks are about 60-70% efficient, depending on the phone's technology, so this power bank is good for charging an iPhone 15 to nearly full, but that big Ultra will only get about 65% charge.