As time goes on, even the most advanced batteries can wear out, especially if they’re constantly charged and discharged.

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. In fact, our testing confirms what battery makers usually claim. A battery maker will claim between 60% and 70% efficiency, so that 10,000mAh battery will only give your phone around 6,000mAh of extra battery charge, at the least. In practice we find around 65% efficiency, though occasionally we can do even better. 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 want a more portable option: Because of its combo nature, the Anker 733 is a bit bulky and cumbersome, but if you use it both ways, it's worth the trade-off in size to have such a useful device.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. The bottle is actually a nice, insulated affair, and it kept ice in cold water for 12 hours, which is all that we need. It has a good, strong strap to carry the bottle, though we would have liked a lid that was easier for sipping. 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).

A power bank is a portable charger that can store energy and output it to electronic devices like smartphones, tablets, laptop computers, e-readers, etc. A power bank can also be called a portable charger. It might be difficult to recharge the power bank batteries if they’re completely depleted for any reason and the voltage falls below a certain threshold. Keep in mind that you should always use a USB cable supplied by the vendor or a short, high-quality USB cable The battery in your portable charger might have worn out if you’ve been using it for more than a couple of years. Extreme Temperatures

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. You can also charge the Anker Prime using both USB-C ports at the same time, for a combined recharging rate up to 170W. That means you can completely refill this whopping 27K mAh battery in under 40 minutes. I thankfully had an Anker 737 GaN Prime charger that was up to the task, and it's fun to see the percentage climb. Everybody on our gift list who got a new iPhone is going to get an Anker Nano Power Bank (22.5W) this year. This cute little charger is perfectly sized to sit beneath your favorite smartphone, plugged into the USB-C port with a little plug that opens out or hides away for a sleek look.

The next question is how you want to charge your device. You can find a power bank that charges your phone (or even your Apple Watch) wirelessly. These will usually charge slower, but they can be very convenient if you want to leave wires at home. We expect this competition will heat up next year as more power bank makers catch up and make faster charging batteries. Until then, Anker is the dominant brand, and if you want the best it's an easy choice. How many times can my power bank charge my phone? 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.

Smaller portable batteries with capacities of 5,000mAh and 10,000mAh are available, but a 20000mAh power bank will last longer and should be able to charge your phone battery numerous times. Why Is My Power Bank Taking so Long to Charge? If your equipment is at least somewhat new, you might still be protected by a manufacturer’s warranty. If the maker finds that you’ve been using your device responsibly and that it’s still within the warranty period, they might offer to fix or replace it. Power Bank Maintenance When the battery compound of the external battery has been used up, it no longer functions as intended. It can’t be recharged and the battery loses its ability to hold a charge. Remember not to leave the lithium-ion battery power bank charging longer than necessary. FAQ How Long Do Power Banks Last?Tylt also wisely left enough of a gap between the battery and the bottle that you can coil a small USB-C cord (included) into that space. That way, even if you're not charging wirelessly, you're not adding a lot of extra bulk to your bag. It's a smart setup. 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 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.