We’ve all experienced that moment, when we run out of battery juice in the middle of the day thanks to some power hungry apps. It is evident that most of our lives revolve around our smartphones. So whether you use yours for gaming, productivity or entertainment you are guaranteed to charge your smartphone once a day of course depending on your usage. Smartphone battery technology is stuck in the past, there has been not much innovation in this area, yet phone processors and apps get sophisticated every year. So, smartphone makers have come up with several “fixes” to ensure that battery life if on par with expectations from customers and that phones can last through at least a day of use. These include thing like fast charging, wireless charging and removable batteries. But, the most commonly used are portable Power Banks– these charging gizmos always come in handy to save the day and help top up our smartphones and enable us go an extra mile especially if one is on the move. Today, we bring you 5 things to look out for before you buy yourself a portable power bank.

Size and Portability

Power banks come in different shapes, deigns and sizes. Size is one of the qualities you should consider when buying a good power bank for your smartphone. Remember, this is a gizmo you will be carrying round fairly frequently. You should therefore buy one that will not be an extra burden in terms of adding more bulk in your handbag or pocket. Some people don’t mind having larger sized power banks since they are in most cases capable of storing more battery capacity. So a trade-off has to be made between how much capacity you need vis-à-vis its size.

Battery Capacity

Warning Math Ahead! As you embark on your power bank shopping voyage, you will need to understand the power storage capacity of battery banks. Okay let’s try this; in case you already own a power bank you will find somewhere at the back or bottom depending on its design the battery rating. This rating is always measured in units known as milliampere hour (mAh). This is a 1000th of an ampere hour (Ah). Both measures are commonly used to describe the energy charge that a battery will hold and how long a device will run before the battery needs recharging. In simple terms, there bigger the value of mAh, the more battery capacity it will store.

Power Banks mAh ratingAll you have to know is most battery banks have capacities that range from 2,500 mAh to 20,000 mAh the larger the capacity the pricier it gets. Most power banks come with lithium-ion or polymer cells with a rated output voltage of 3.7 or 5V. The standard input voltage of smart devices is 5V so power banks need an output of 5V to charge smart devices. Let’s take an example, I have a 12,000 mAh rated power bank, and if I need to find out how many times it can theoretically charge my 3,000 mAh smartphone from 0 to 100%, I will need to consider the calculation below. This shows that the battery bank is able to charge my phone at least two to three times depending on its output voltage.


so 7192.8mAh/3000mAh=2.4 times or 3.4 times with a 5V output power bank

In first time 0.9 means 10% loss from boost converter in the power bank and second 0.9 means 10% loss from smartphone circuitry.

The extra Features

4 USB ports, Water resistance, battery LED indicator lights, Quick Charge, torch, SD-card capabilities and Wireless Charging are just a tip of the iceberg of what can be incorporated in a power bank. These are just add-ons that may not be necessary, but preferable for a few. You can also make a choice based on this.

Power input/output (Time taken to charge)

It’s not enough having a power bank. Also, we need to get power banks that are able to charge quick and at the same time be able to charge the phone very fast. Basically, shorter battery charging time is always preferable. Most power banks come with lithium-ion or polymer cells with a rated voltage of 3.7V. So what can one look out for?

You should buy a power bank that allows at least and Input and Output of 5V/2A, if you have a power bank with more than one USB output port, ensure that at least one port capable of fast charging. Lower charging times are always preferable.

Pricing and Authenticity

Honestly speaking, don’t expect a power bank with killer features and massive battery capacity to come cheap. You can hit your favorite and trusted electronics shop or e-store for actual prices. Be aware of cheap power banks that go for as low as UGX 20,000 ($6), chances are high that you are buying a counterfeit device. So what can one look out for? You can look at the branding, printing at the bottom as most fake products tend to have inconsistent and unrealistic numbers printed on their power banks.

At the end of it all what matters is the amount of money you’ve set aside to buy a power bank. It’s not a guarantee the most expensive power bank is the best power bank– I have been there before. Always strike a balance and look out for the tips mentioned above. Want to share your power bank experience? You can jot it down in the comment section below.