With more power comes.…more productivity. In this ever connected mobile era, our smartphones and tablets are our gateway to the world. They are essential tools for modern living. We use them for work, for communication, for entertainment— a lot of people just can’t get by on a day to day basis without them.

But despite them being high tech and all, the fact remains that these mobile devices are one of the most power-hungry gadgets around. All of the technological advancements in the last few decades still hasn’t produced a viable battery for mobile gadgets that can last for a couple of days or so. With WiFi and Bluetooth on, even the latest smartphones can’t last for a few hours.

So, the solution for this modern dilemma is external battery chargers. These devices (also called as “power banks” in the vernacular) are portable devices which you plug your smartphone or tablet into when your battery runs out and you can’t access a wall outlet. These things are essentially a lifesaver when you need to send an urgent email or book a last-minute emergency flight on the road.

How Do I Choose the Right Power Bank For My Needs?

Before buying the first power bank that you see on the shelf of your local electonics store, you need to consider a few things first. First of all, determine how much power you actually need. Smartphones like the Samsung S series and iPhones usually have battery capacities around 2100mAh (milliampere hours), while tablets like the iPad air and Samsung tabs are around (11560mAh). This kind of information can usually be found on the battery itself or on the manufacturer’s website.

As you can see, there’s a huge difference between the battery capacities of smartphones and tablets. The power bank that you’ll choose should be able to accomodate the mobile gadgets tht you intend to use when you’re on the go. An external charger that provides at least 10000mAh of juice can fully power at least three smartphones, while it can only partially charge a tablet like the iPad air.

Next to consider is the bank’s physical size. There are external chargers that are no bigger than an oversized lipstick, while some are big, bulky things that are around the size of a small notebook. The smaller ones provide the least juice of course, but if you need something that you can stash easily in a small purse then these smaller chargers might be the right fit for you.

And lastly, take note of the battery charger’s amperage rating. The amperage measures the rate at which a battery pack can charge your device. Older power banks used to have at least .5A and 1A, and these are usually enough to charge most smartphones. Tablets need around 2A before their batteries can be properly replenished.

If you ever experienced plugging your tablet into a USB port and then receiving a prompt that your device is “plugged in, but not charging” then this just means that the amperage rating for that particular port is too low to support charging your device.

Five Great Power Banks

If you’re still confused on what external charger to buy, here are five models that have greatly exceeded consumers’ expectations:

1. Anker Astro E7 Ultra-High Capacity 26800mAh

Anker Astro E7 Ultra-High Capacity 26800mAh

Anker Astro E7 Ultra-High Capacity 26800mAh

Providing 25600mAh of juice, the Anker Astro E7 Ultra-High Capacity external charger is a power giant packed in a small, portable form factor. It’s clear why this brand is Amazon’s top brand in the power bank field- it gives you the most power for your buck.

This device can charge the power-hungry iPhone 7 Plus or the Samsung Galaxy S8 six times over. It can also fully charge most Android tablets and the iPad twice. If you’re going on a long trip and need to have your mobile devices with you, then the Anker Astro E7 is a must-have.

2. Vinsic 20000mAh Ultra-slim Power Bank

Vinsic 20000mAh Ultra-slim Power Bank

Vinsic 20000mAh Ultra-slim Power Bank

Don’t let the slim form factor fool you. The Vinsic 20000mAh Ultra-slim Power Bank provides an impressive amount of juice in such a slim build. You can easily lug this thing around in a purse or a bag. Also, the device has two USB ports which means that you can charge two devices simultaneously.

The best thing of all? The Vinsic has all sorts of protection against overcharging, overdischarging, over-voltage and other circuit issues. Not only does this thing power up your device, it also helps make it last longer too. You can’t get any better than that.

3. ALLPOWERS™ 3nd Gen 3.5A Output Portable 15600mAh

ALLPOWERS 15600mAh Power Bank External Battery Charger for Smartphones, Tablets and other USB Devices

ALLPOWERS 15600mAh Power Bank External Battery Charger for Smartphones, Tablets and other USB Devices

An amperage rating of 3.5A means that the ALLPOWERS 3nd Gen Portable can handle the most power intensive of mobile devices (i.e iPad air and other similar tablets). Aside from its impressive charging capabilities, the unit has AllPower’s patented iPower Fast Charging technology which automatically adjusts the current voltage to provided maximum juice output to your device.

This power bank is compatible with most smartphones and tablets, as well as portable game consoles (PSPs), digital cameras, GPS units, and bluetooth speakers.

4. RAVPower Xtreme Capacity 22000mAh

RAVPower 22000mAh Portable Charger

RAVPower 22000mAh Portable Charger

Unlike most external chargers, the RAVPower Xtreme Capacity 22000mAh earns the distinction of being able to charge three devices all at once. You get 1.0 A and 1.5A ports for smaller devices like smartphones, and another 2.4A output for tablets.

The brand’s patented iSmart technology also ensures that each of the devices connected to the unit is provided enough power while charging at full speed. And unlike other brands, the RAVPower actually has an LCD screen instead of the usual LED lights so that you can easily see how much power you have left.

5. EasyAcc® 20000mAh Dual USB Power Bank

EasyAcc® 20000mAh Dual USB Power Bank

EasyAcc® 20000mAh Dual USB Power Bank

20000mAh is a lot of juice. The EasyAcc® 20000mAh Dual USB Power Bank can easily power up an iPhone nearly ten times or an iPad air twice. With an output of two USB ports, you can easily charge two devices simultaneously. Another great thing is that the unit has a clear digital LED display (not LED lights) that displays the remaining battery as a percentage– which means no more guesswork when you want to compute how much power you have left!

The output ports are compatible with a wide range of mobile devices like Bluetooth speakers, PSPs, headphones, and even Google Glass.