Buying Guide for Power Banks

Power banks are a great add-on to our lives where the need for staying connected 24x7 forces us to desperately seek wall chargers and charging points when our devices are running out of battery juice. With their portable size and the ability to charge your mobile devices on the go, power banks have become an essential part of our gadget collection. For frequent travellers and camping enthusiasts, a power bank can be an indispensable tool as you may often find yourself without a power source for long periods of time.
This power bank buying guide has detailed information on the various features and terms associated with power banks and will help you select the right one for your needs.

What is a Power Bank?

A power bank is a portable battery charger for mobile phones, tablets, digital cameras, laptops and other digital devices. It consists of a built-in battery of variable capacity that can store electrical energy for subsequent charging use. This stored energy is measured in a unit called mAh (mili ampere per hour) and this unit determines the charging capacity of a power bank. All power banks contain one or more USB ports to charge devices and a charging port, mostly micro USB, to charge the power bank using an external charger.

What are the different types of Power Banks available?

Like any other device, power banks are available in different types.
1.Universal power banks can be used to charge almost any device that requires a USB-based charging unit.
2.Solar-powered power banks receive their electric charge from sunlight and can be extremely useful during power cuts and camping sessions. As solar-based charging is way slower than regular electrical charging, these power banks can be charged using both methods, with solar charging restricted to being used in emergency cases. These power banks are generally more expensive than their regular counterparts.
3.Phone battery covers or power cases are phone cases that feature an additional battery to supplement your phone’s built-in battery. Due to the sheer number of phones available now, these devices are getting obsolete and are presently available only for top smartphones.
4.Other types of power banks include ruggedized ones for usage in all weather conditions and smart power banks that adjust voltage and output current according to the device being charged.
What Power Bank to choose?

Before buying a power bank, you should determine how many devices you would need to charge on a daily basis and your intended use for it. Most present-day phones come with a 2,500 to 3,000 mAh battery. For charging these phones 2-3 times on a single power bank charge, you would need a 10,000 mAh battery. For instance, the Samsung Galaxy S7 has a 3,000 mAh battery and to charge it twice, you would need a minimum 8,000 mAh power bank, keeping the efficiency figures of the power bank in mind. This efficiency factor is discussed in the next section.
Larger devices such as phablets and tablets come with higher capacity batteries and for such devices, a power bank with a minimum of 20,000 mAh capacity should be chosen. Larger capacity power banks are usually bulkier because of the bigger batteries required in these devices. The fine balance between size and battery capacity needs to be determined based on your usage pattern and requirements.

What does Battery Efficiency mean?

Going by pure numbers, a 5,000 mAh power bank should be able to charge a phone with a 2,500 mAh battery twice. However, there are a number of factors involved inside the battery’s circuitry that prevent this from happening. The resulting loss of battery energy plays a factor in determining the power bank’s efficiency factor. This is why the actual capacity of a power bank is always less than its advertised capacity and this should be kept it mind while choosing one for your devices.

What are the different types of batteries found in Power Banks?

All power banks feature mainly two types of batteries – Lithium-ion (Li-ion) and Lithium-Polymer (LiPo). Li-ion batteries come in a cylindrical-shaped plastic case. These batteries require low maintenance and are cheaper than LiPo batteries but have a higher energy density. LiPo batteries are thinner and lighter but also cost more and have a lower energy density than the Li-ion ones.

Additional Features

As they contain batteries, safety features in power banks such as protection from short circuits, overcharge, over-discharge, overheat and input voltage protection are very important. Some power banks also come with special features that enhance their functionality. Most of them feature charging level status in the form of LED lights or a monochromatic LCD display to indicate the amount of charge left in the power bank.
Some power banks have two or even three charging points, so that you can charge multiple devices at the same time. Few manufacturers equip their power banks with an LED flashlight which can be an extremely important tool for outdoor camping trips or even during a power outage.

Power Banks come in all shapes and sizes

From ultra sleek models that are no thicker than a small mobile phone to ergonomic brick-shaped ones that can be easily held and carried around, power banks come in a wide variety of sizes and colours. The outer casings of these power banks are made of plastic or lightweight metal such as aluminum.
As discussed above, slimmer sizes come at cost of lower battery capacities. Although there are keychain sized power banks available as well, they have more of a gimmick value rather than actual practical use.

What brand should I go for?

You must choose your power bank from reputed manufacturers and big names in the industry such as Xiaomi, Lenovo, Ambrane, PNY, OnePlus, Intex and more. Due to the prevalence of low quality batteries found inside them, generic power banks must be avoided at all cost. These cheap power banks provide inefficient charging, are devoid of any protection features and are known to explode due to overheating upon charging.
Usage Tips
For ensuring optimum performance and longevity of your power bank, the following things should be taken care of:
1.Do not overcharge the power bank
2.Always use branded charging cables
3.Data cables are generally not as efficient as regular charging cables and should be avoided
4.Try to avoid using your power bank in extreme weather conditions
5.Do not use your phone while charging as the resultant increase in battery temperature reduces the lifespan of both the phone and the power bank