This lightweight battery pack ships partially charged and is small enough to easily slip into your backpack, purse, or pocket.
The charging cable is very short.
It can charge most phones up to 3 times and can also charge tablets, smart watches, and fitness bands.
While it has a fast charge option for capable phones, it doesn't have a second port for the option.
This very sturdy power bank's charge will last all day, enough to charge a phone 3 to 4 times, and never seems to run out of juice.
It's a little larger and heavier than expected.
Able to charge several devices before needing to be charged itself, and has two output ports – 2.4 and 2.1 – that both have smart charging.
It can take a while to charge itself.
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Since the dawn of the smartphone revolution, we’ve lived with ongoing angst that we’ll someday run out of battery at exactly the wrong time. Whether it’s a TV binging session or a video call with a loved one, no one wants their device to die in the middle of something important. To tackle this fear, a new product has emerged: the power bank.
Power banks are batteries inside metal or plastic enclosures that you can use to charge your devices. They’re perfect for situations in which your phone needs some juice and there are no outlets to be found.
At BestReviews, we believe in providing honest reviews of relevant products. Read our shopping guide for power banks to get a grasp on which type of power bank may be best for you. Then, check out the product matrix above to see our most recommended models.
There are a lot of different features that differentiate various power bank models, but far and away the most important one is storage capacity. A power bank has one job: to receive and store energy for your devices. It makes sense, therefore, that available storage is the most important attribute.
Power bank capacities are rated in milliamp-hours (written as mAh), which is a measurement of charge that’s sometimes referred to as current flow over time. So how many milliamp-hours do you need?
Consider these comparisons.
iPhone batteries typically have a capacity of around 2,000mAh.
Samsung Galaxy phones have a battery that stores 3,000mAh.
Typical laptop batteries store 5,000mAh.
Power bank capacities vary widely across the market, but they will always be listed as part of the product specifications. As you’re shopping for a power bank, make sure to get one that holds enough for all of the devices you want to use it with.
Larger power bank batteries weigh more than their less-capacious counterparts, so keep in mind that carrying around more power with you means carrying more weight as well.
As you’re researching power banks, you’re likely to come across a soup of industry terms. Here are the three that matter the most.
As mentioned above, mAh is a measurement of a battery’s capacity. For example, smartphones generally have batteries with 2,500mAh, and power banks can store anywhere from 3,000mAh to 40,000mAh. The bigger the mAh number, the more power it holds.
Lithium-ion and lithium-polymer
There are two types of batteries used in power banks: lithium-ion batteries and lithium-polymer batteries. The terms describe what the batteries are made with. Both are decent, but notably, li-polymer batteries tend to last longer and cost more. If you can afford to buy a power bank with a li-polymer battery, you should buy it. Otherwise, take heart knowing that li-ion batteries are a completely acceptable alternative.
“Smart Charge” feature
Some power banks have multiple ports, and they’re able to determine the right amount of voltage to use based on the connected device. This feature is often called “Smart Charge,” but in some cases, it’s a feature without separate branding. With Smart Charge, you can be certain that every connected device is charging as fast as it can.
Some power banks are designed only for smartphones and tablets, while others can also be used to power laptops. If you’ll be using your power bank with more than just mobile devices, be sure to get one with a higher voltage output (typically 16V to 20V will be required, depending on the laptop). Most smartphones and tablets only require power banks that draw 5V of power.
Power banks are generally affordable, but it’s important to know what you are – and aren’t – getting for your money. As you’re picking out a power bank, keep these three main price ranges in mind.
In the $10 to $24 range, you’ll find low-capacity batteries and no-name brands. Power banks are a great example of “you get what you pay for,” so it’s best to avoid models in this price range.
In the $25 to $50 range, expect to see the best performers. Power banks in this range have ample storage, plenty of connectivity options, and handy bonus features like LED status lights that indicate how much power is left inside.
Some power banks offer multiple inputs, so you can charge more than one device at a time. Just remember when you connect two devices, your power bank will drain twice as fast.
As you’re shopping for a power bank, consider these tips.
Buy a dedicated USB cable for your power bank, and keep them together at all times. It’s easy to lose track of USB cables, so make sure you’ve always got one handy when you’re ready to use your power bank.
If you don’t expect to use your power bank frequently, set a calendar reminder to charge it. Most power banks will hold energy for a long time (anywhere from weeks to months), but if you only use yours occasionally, you’ll want to keep it charged regularly. No one wants to reach for their power bank during a power outage only to find it’s out of power!
Recharge your phone to 80% or 90% with your power bank; avoid charging it to a full 100%. When a power bank is getting recharged, the last 20% or so will take much longer than the first 80%. What’s more, when a power bank remains plugged in after being at 100%, it’s still consuming energy and replenishing it, wasting battery life.
If you’re often in a hurry, consider a power bank with Quick Charge technology. With this technology, certain Android phones can charge much faster than others. Using Quick Charge, a supported phone can recharge up to 80% of its battery in 30 minutes.
Q. How long do power banks hold a charge when they’re not being used?
A. It depends on the quality of the power bank. High-end power banks can hold a charge for up to six months, and low-quality power banks can discharge completely within a few weeks. If you expect to only use your power bank once in a while, avoid no-name brands and any model that’s poorly reviewed.
Q. How long does it take to recharge a power bank?
A. Power bank charging times vary depending on the power bank’s capacity – larger batteries take longer to charge – as well as the type of power adapter. Some power banks use USB cables for power, while others come with AC adapters that plug into the wall. Not surprisingly, charging from the wall is faster.
The average power bank takes between eight and 12 hours to charge via USB and about half that if plugged into the wall. Not all power banks support both charging methods, so be sure to note which ones meet your charging needs as you’re shopping.
Q. Does it matter if a power bank’s ports are USB 2.0 and not USB 3.0?
A. Yes, sort of. The USB 3.0 standard can transfer more data and power than the USB 2.0 version. This means that if your power bank has a USB 3.0 slot, your device supports the faster charging of a USB 3.0 connection – and if you use a USB 3.0 cable, you’ll charge faster than you would if any one of the components relied on USB 2.0.
The USB 3.0 standard is backward-compatible, so it has no problem charging USB 2.0 devices. If you can afford to, buy a model that features at least one USB 3.0 port.