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Battery Capacity (mAh)

Number of Output Ports


How to Choose the Best Battery Pack

So you’d like to find a way to keep your tabletsmartphone or portable speaker running while away from home but you’re not sure where to start?

External battery packs--also known as power banks or portable chargers--are a popular option for topping off your battery when power outlets are hard to find.

Whether you’re looking to extend your next Ingress session or want a way to keep working on your tablet all the way through your next flight, we’re here to make sure you know how to find the best portable battery for your needs. Let’s get started!

Battery Pack Basics

Once an expensive item for techies and business travellers, improvements in portable charger technologies have made them affordable for virtually any budget.

While this is great, it also means that there are hundreds of models from which to choose.

How do you know which one to pick?

These basics will help give you an idea of where to start.

How Does a Portable USB Charger Work?

Typically, when you need to charge your tablet, phone or other device, you grab a USB cable or other charge cable and hunt down a power source.

Portable chargers work much the same way.

Simply plug it in and charge it up before you leave the house.

Like other batteries, capacity is measured in milliamperes or mAh.

Many powerbank models use both wall outlets or USB ports to charge, providing flexibility in keeping your battery pack ready to go.

When it is time to charge your device, just connect its USB charger to the port of the battery pack.

No more hunting for outlets at the airport or hoping your battery lasts through the morning commute.

When you are done charging, disconnect the USB cable and stow the pack safely in your pocket or bag.

Battery Designs

Depending on their capacity, battery power banks are available in a variety of sizes and formats.

In general, smaller chargers have a lower capacity.

Lower capacity chargers are also much lighter than those of higher capacities, often no larger than a tube of lipstick or a few credit cards.

A 30,000 mAh battery pack can weigh as much as two to three pounds and take up as much space as a deck of playing cards or small paperback book.

No single design is immediately better than another.

The most important things to consider are how you plan to store and carry your portable charger and what mAh capacity will meet your power needs.

Portable Chargers - What You Need to Know

So you have a basic idea of what to expect from a portable charger.

Now we’ll get into the finer points.

How do you know if you need a large or small charger?

Can you predict just how much of a charge your pack will give your phone or tablet?

Will any pack charge any device?

Let’s dig a little deeper.

How Much Juice is Enough?

One of the most important considerations to keep in mind while shopping for a power bank is its capacity.

Too little and you’ll still be stalking power outlets.

Too much power and you might spend more than needed or end up with a bulky pack you don’t need.

While technical issues, such as efficiency and drain while charging, might impact how many charges you can get from your pack, there is a basic way to estimate how many times your battery pack will recharge your phone or tablet: divide the mAh of the battery pack by the mAh of your device battery.

For example, if your phone has a 2,500 mAh battery and you’re looking at a 10,000 mAh battery pack, you can estimate that you’ll be able to charge your phone approximately 4 times on a single battery pack charge.

If you have multiple batteries to charge, adding their capacities before dividing will give you a better estimate.

Charging Speeds and High-Drain Items

As phones and tablets have become more powerful, they’re demanding more of their batteries.

To help speed up the charging process and account for this high battery drain, many tablet and phone manufacturers are now using high-output chargers.

When choosing a portable USB charger, it is important to know if it will charge a high-drain device.

If you intend to charge a tablet of any kind, it is almost guaranteed that you need a high-output charger.

Many new smartphones will need one as well.

To check if a battery pack is high-output, all that you need to do is check the amp rating on the USB or charge ports.

Currently, 2.1 amps is the ideal output for high-drain devices.

If the pack that you are considering includes a 1 amp port, it might hold the battery steady under use but will fail to increase your charge level unless your phone or tablet is in standby.

Older 0.5 amp battery packs simply cannot keep up with many modern devices.

The exception to this is low power devices, such as eInk readers, wireless headphones, bluetooth headsets and other smartphone accessories.

Advanced Considerations

We’ve covered everything you need to know to pick a reliable battery pack.

However, there are still a few topics that might be handy if you’re looking for the absolute best.

With the sheer number of options available, it is often the extra features that make one pack stand out from the next.

We’ll go through a few of the most popular options now.

Multi-port Battery Packs

Not only is it common to carry a phone, tablet and bluetooth headset at the same time, but you might even use them all at once.

So what do you do when you need to keep multiple gadgets up and running?

Get a portable USB charger with multiple ports!

In general, these chargers operate identically to their single port counterparts.

If you’re not in need of high output ports, just find a charger with the number of ports that you need.

However, if you plan to charge a tablet or newer items, be sure to check the amp rating for each port.

Many cheaper multi-port models only offer 2.1 amps on a single port.

Charge Indicators

Your battery pack is only useful if it is charged.

While most batteries offer some form of warning when your capacity is low, spending a little extra money on a pack that offers a detailed charge level indicator will help prevent being surprised by a low battery while on the go.

Beware the Extras

It seems that battery packs are receiving upgrades of all sorts lately to lure buyers in.

From flash drives and flashlights to fancy covers and a dozen charging adapters, the options are endless.

However, consider what you really need before dropping extra money on a feature that might sound nice but is rarely used.

What Type of Battery Pack is Best for Me?

So we’ve covered everything you need to know about battery packs and all that is left is picking one up.

If you’re still unsure as to what pack would best suit your needs, consider these usage types:

Gadget Guru
You don’t just have the newest phone and tablet, you have backups in the event you drop one. You might even be found camping for a release date or two. You are connected 24 hours a day and need additional power to keep things up and running.

In this case, you should consider a high mAh pack with multiple high output ports.

Frequent Flyer
Your office is whatever hotel you are in on a given day. You no longer suffer from jet lag because you’re never in the same time zone for more than a few days. You need to be able to use your phone or tablet from a mile above sea level.

In this case, a high capacity pack is essential. Since you’ll likely have a carry-on or other bags, size is less of a concern. High output ports will ensure you can work from your seat from taxi to landing.

Mobile Gamer and Movie Junkie
Whether you’re racing, spelling, spinning or slaying, your phone is as much an entertainment center as it is a way to communicate. You have the latest phone and a massive memory card so you can carry your movie collection with you and enjoy silky smooth game play.

For you, the number of ports isn’t as important as portability. Check your phone specs and consider a battery pack that will double your battery life with a high-output port that can keep up.

Emergency Power
You don’t use your phone much, but you worry that one day you’ll need it and it won’t be charged.

You want something you can toss into your bag or vehicle that you can forget about until needed.

A simple 2,000 mAh, single-port battery pack will provide enough juice to let you find help or get to safety. Be sure to periodically check the charge on the battery if you are storing it unused for extended periods.

Your Turn

So there you have it! Everything you need to go out and buy a battery pack with confidence.

If you’re in need of a few suggestions on popular models, don’t forget to check out our battery pack reviews.

If we missed anything or you have a question to ask, get in touch or ask a question in the forum!

We’d love to hear from you!