Once power banks were a niche product, but with phones, tablets and other devices now imperative to daily life, they’re a must have the world over.

The popularity of power banks is even higher here in South Africa because of loadshedding. While those in other countries may view these products as a way to keep your devices charged when away from the plugs, South Africans see them as a way to keep going when the power is out.

Despite this adoption many may not know how to approach buying a new power bank, especially around the most important feature: capacity.

On the surface it may seem like a simple situation of “more is better” when it comes to power bank capacity. This is intuitive, but it betrays other factors namely price and size.

So let’s start with the basics: what is capacity? For battery banks capacity refers to the size of the battery illustrated in milliampere hours represented by the abbreviation “mAh”. This is a simple measure of power (milliamp or mA) over time (hour or h).

Romoss, one of the biggest names in the world of power banks for their high build quality, dependability and great prices, sells power banks in a variety of capacities with some of the most popular being 20 000 mAh, 30 000 mAh and 40 000 mAh.

Let’s take the 30 000 mAh power bank as an example, like the Romoss Sense 8F 30 000mAh. Let’s say a hypothetical device draws from this power bank 300 mA, that means that the power bank can feed it power for a hundred hours.

Now these calculations can become rather complex for several reasons, such as the fact that no circuit is perfect so energy is lost to heat, and the fact that the amount of power drawn by smart devices changes drastically. Even a phone or tablet that is not being currently used is still doing a lot of background tasks that will change its draw on the power bank.

Those who want to avoid a math problem at checkout should take the advice we give family and friends: do you already use a power bank? Think back at its usage and if you want more or less power, weighed against cost and size that we will discuss next.

Also consider that power banks, like all products with batteries, will become less effective over time, holding less charge and charging slower as the battery degrades. This is why a new power bank with the same capacity as an older power bank may perform much better.

This is also why we always recommend buying power banks from trusted companies like Romoss, whose power banks stand the test of time and can be relied on for years.

With capacity explained we can return to the factors of price and size. A higher capacity, usually, means a more expensive product so this needs to be factored into your budget.

A higher capacity also, usually, results in a physically bigger power bank. Not only is the battery inside larger, but the other electronics inside need to be beefed up, and the entire housing must be expanded to incorporate the extra size. Sometimes larger power banks also opt for thicker components in this housing for better protection of the heavier electronics.

All of these factors need to be considered when buying your new power bank. If you, for example, prefer to charge your devices by leaving them in one place while you do something else during loadshedding, a higher capacity, larger power bank is probably the better fit.

Do you instead like to charge on the go, either by using your device while it charges or in cases of travelling? Look for something smaller to make transport easier.

Once you know what power bank best suits you, shop the entire Romoss range from South Africa’s favourite online store, Takealot.