Why Buy an External Battery Pack?
The top performers in our review are the Anker Astro E3, the Gold Award winner; Limefuel Blast L130X, the Silver Award winner; and Jackery Giant+, the Bronze Award winner. Here’s more on choosing a product to meet your needs, along with details on how we arrived at our ranking of the top 10 external battery packs.
As mobile devices get more powerful, they need more energy to keep them going. Average smartphone battery life hasn't increased much in the past couple of years, which is unfortunate because many people rely on smartphones for access to social media, music and other entertainment. An external battery pack can give your smartphone or tablet the extra juice it needs to last for an entire day of heavy use or even up to a week of medium and light use.
Extending your smartphone's battery life can be especially useful when you're traveling and you're not entirely sure when you'll find an outlet to charge your phone. The best external battery packs are highly portable, allowing you to take them with you when you're away from your home all day long. A high-capacity external battery pack can recharge most empty smartphones three or four times over, keeping you constantly connected – even when there aren't any available outlets.
There are quite a few options when you're looking for a mobile phone battery pack. We've researched about 30 products and narrowed them down to the 10 best mobile battery packs. We eliminated some due to cost and others due to low capacity. When you're on the go, you want to make sure that your battery pack can keep your devices charged for a long time. For that reason, we favored high-capacity battery packs.
What You Should Know About External Battery Packs
There are a few important things to know about external battery packs before you decide which one to buy. The internals for each battery pack can differ significantly among each other. While it may seem a bit technical at first, we'll walk you through the important information and explain why it's relevant. To learn even more, check out our articles on external battery packs.
Most external battery packs come with at least two USB ports. They're usually labeled as 1A or 2.1A. This means the ports can handle up to 1 amp or 2.1 amps, respectively. What's difficult to find is the max output across all ports the battery pack can handle. For example, the Anker Astro E3 has two ports, one rated for 1 amp and the other for 2.1 amps. The battery pack's total output maxes out at 3 amps.
What that means is you will get the full capability of both ports if you use them at the same time, meaning faster charge times for the devices you plug in. Not all external battery packs have a large enough combined output to cope with each USB port being used simultaneously. This is especially a concern with battery packs that have more than two USB ports.
Having an external battery to charge your mobile devices is all well and good, but how long does it take to charge the external battery to full capacity? Obviously, you want this to happen as quickly as possible so that you don't have to charge the external battery while you sleep. The best products reach full charge in six hours or less. Some take up to 12 hours, which is far too long. So, what determines how quickly an external battery can charge? There are several factors to consider.
Of course, a high-capacity battery takes longer to charge than a low-capacity battery. One other major factor is the input USB port's rated amperage. This helps determine how much electricity can pass through the USB charging cable to the battery at any given time. The best USB input ports can handle up to 3 amps, which generally results in charging times of six hours or less.
A mobile phone battery pack doesn't do you much good if it's too large to take with you anywhere you go. You should consider not only the volume of external battery packs, but also their shape and weight. A square battery pack isn't likely to fit in as many places as a rectangular battery pack. There's a good reason why smartphones have mostly evolved to be rectangular in shape – because it's a very portable shape.
You'll want to bring your external battery pack with you wherever your mobile devices are. This means a lot of travel and all of the wear and tear that comes with it. The housing material can make a large difference not only in an external battery pack's aesthetics, but also its longevity.
Metal housing ensures that the device will survive most drops and normal wear and tear for years. It's also good at conducting heat out and away from the external battery's internal components, which can help the battery itself last longer. When it comes to any electronics, cold is good and getting rid of heat usually improves performance.
You don't want to constantly wonder how much of a charge remains in your external battery, so some form of indicator is necessary. Many external battery packs use LED indicators to show you a relative percentage of charge remaining. The best LED indicators have more than four LEDs to show you a more accurate representation of how much charge is left.
While extras like a built-in LED flashlight may seem silly, they can be very useful in the right situations. A low-battery warning is especially useful when you have two devices plugged in at once, as that can drain the external battery's charge quickly.
External Battery Packs: Our Verdict and Recommendations
We determined that the Anker Astro E3 earns our Gold Award and is the best overall external battery pack due to its high capacity, quick charge time and excellent portability. The Astro E3 isn't necessarily the best in every category we looked at, but it comes out on top overall. One particular aspect of the Astro E3 that makes it an attractive options is its 3-amp input. This allows the Astro E3 to reach full charge much more quickly than other external battery packs.
For a very high-capacity and well-constructed external battery pack, you'll want to look at the Limefuel Blast L130X, our Silver Award winner. This is a device that will last you for a long time and has a large enough capacity to completely recharge most tablets. It can recharge most smartphones four or five times. The Blast L130X also has the highest amperage rating across its ports. That means you'll get faster charging times if you have more than one device plugged into the L130X at a time.
The Jackery Giant+, our Bronze Award winner, has just about every extra feature you could ask for. It's also one of the sturdiest external batteries you'll find, thanks to its aluminum housing. While the Giant+ doesn't excel in specifications, its extra features may be enough to pique your interest.
The HyperJuice Expand external battery pack is incredibly versatile. Especially if you need a battery pack that has more than two USB ports, the Expand is a good fit. You can swap out batteries for different purposes. For example, if you want ultimate portability for a day, you can use the smallest-capacity battery. However, if you need more juice, you can throw the high-capacity battery on and not have to worry about running out of power anytime soon.