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. 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.

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. Originally Dewalt battery casing would hold several smaller cylindrical batteries that work together to power in a similar way an AA battery would work and look. These batteries are then laid into a case and set up to interact with tools. The best power banks we have tried have all come from Anker, but that doesn't mean Anker is the only brand you should consider. All of the power banks on this list passed our testing, traveling with us on the road and powering our devices at home. Anker is the best, but these batteries from Baseus and Otterbox performed well.A big power bank with 20,000mAh or more will deliver almost five charges for an iPhone 13 – and we’d recommend this size if you want to charge bigger batteries like those in an iPad or laptop. These are also about as big as you can bring on a flight (more on that below). 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. 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. Portable devices have a Murphy’s law–like ability to run out of power at the least convenient moment: as you step on the bus, right in the middle of an important meeting, or just as you get comfortable on the couch and press Play. But if you keep a battery-powered portable charger handy, all those situations are in the past.

Think about how you’ll be carrying it around and what you need it for – a power bank for your bag can be quite different than one for travelling or camping. Goal Zero updated its Sherpa line of portable chargers with better wireless charging capabilities: 15 watts, up from 5 watts in the previous model. I tested the Sherpa AC, which features two USB-C ports (60-watt and 100-watt), two USB-A ports, and a 100-watt AC port for those devices that need a pronged plug. It strikes a good balance between power storage (93 watt-hours in my drain test) and weight (2 pounds). It’s enough to charge up my Dell XPS 13 almost twice. But, you only need to worry about the basics to make sure you’re getting the right one for your needs. Most importantly, is it the right size and weight for your needs? Does it have enough ports? And is there enough juice to charge up all your devices? Capacity On test, we found that this was able to restore 50% of our MacBook Air’s battery in 43 minutes with the supplied USB-C cable, and while it wasn’t quite able to get the battery to fully charge, it finished up at 98%, so it has a high enough capacity (enough for almost six recharges of an iPhone 14) to keep your laptop and phone going during your travels. 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.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). One USB-A port (18W) and one USB-C (18W). Can charge most smartphones two or three times (10,000 mAh).

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. Don’t know your USB-A from your USB-C or Micro USB? It doesn’t have to be too confusing. The older USB-A is the connector you’ll have seen often over the past 10 years or so (think little portable USB drives) while the newer USB-C connector is the one that has come with the newest Androids and iPhones (on one end at least, these still charge via Apple’s Lightning port). 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 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.

Recommendations

The chemical reaction that occurs inside a lithium-ion cell is complex, but as in any battery, there's a negative and a positive electrode. In lithium batteries, the negative is a lithium-carbon compound, and the positive is cobalt oxide (though many battery makers are moving away from cobalt). These two compounds cause a reaction that is safe when controlled and delivers energy to your devices. When the reaction gets out of control though, you end up with earbuds melting in your ears. What changes a safe reaction to an uncontrolled reaction can be any number of things: excess heat, physical damage during use, physical damage during manufacture, or using the wrong charger. We like wireless charging as a fuss-free way to refuel smartphones and earbuds, although it’s worth noting that it’s slower than the traditional wired approach.