What Size of Power Bank Should You Buy

Power banks are the lifeline for many who are often on the road. These rectangular devices provide the needed power when the battery on our smartphones runs out. Besides that, they save you from scrambling to find a wall adapter and a power outlet. All you need to do is plug it in, and that’s it. However, one of the most important things to check is to check the power banks size and capacity.

You wouldn’t want to lug a huge brick around if you use a power bank sparingly. And the opposite is also true. A small power bank won’t do any good if you are often on the road. Hence, you must pick the right size of the power bank. Besides that, you should also calculate the number of devices you need to charge and the charging speed.

So, if you are planning to buy a power bank for your tablet or smartphone, this guide will help you pick the right power bank size for you. Let’s get started. But first,

• Let go of the hassles of wires with these power banks with built-in cables
• Love traveling? Here are our top picks for high-capacity power banks for travel
• Check out these power banks for laptops that you can buy

1. How Many Devices Will You Connect

How many devices do you plan to charge on your power bank daily? Is it just your smartphone? Or do you plan to fuel your headphones and tablet?

If you plan to refuel your wireless headphones/earphones or your watch, you are in the safe. This is because these devices do not eat much stored energy compared to other power-hungry devices like tablets and laptops (yes, some laptops charge via power banks and vice versa).

For instance, wireless earphones like the Apple AirPods Pro have a mere 45.4 mAh battery. And smartwatches like the Samsung Galaxy Watch 4 have 361 mAh batteries compared to the whopping 5,000 mAh of the Galaxy S21 Ultra.

The bottom line is that the number and type of devices also play a crucial role in buying the right power bank size.

2. What mAh Power Bank Should You Buy

Now, coming to the most important part — what should be the battery capacity of your power bank? As noted earlier, the math is simple. A small power bank should provide around a single round and half of the charge cycles for a phone on a good day. When we say small, we mean around 4,500 mAh – 5,000 mAh power bank. These small devices should be good enough to charge a budget smartphone fully.

For example, if you have the Google Pixel 7a, the Miisso 6,000 mAh portable charger should be good for backup.

However, if you have a smartphone with a large battery or a laptop, you should opt for a heavy-duty power bank. However, it’s not as simple as buying a 5,000 mAh power bank to charge a 5,000 mAh smartphone. Life should be that simple, no?

When calculating the power bank capacity, you’ll have to consider the conversion ratio. When it comes to smartphones, the power rating is calculated at 5 Volts.

But, in the case of power banks, the power rating is calculated at 3.7 Volts. This is because they carry Li-ion (Lithium-Ion) battery cells. And naturally, this difference causes a step down in the charge cycles.

Thankfully, there’s an easy way to calculate the actual power of each device as per its capacity.

Here, let’s take the example of the 5,000 mAh power bank.

Total energy of the power bank is 5,000 mAh x 3.7V = 18,500 mWh.

Converting back to 5V, the capacity is 18,500 mWH / 5V = 3,700 mAh.

Hence, a 5,000 mAh power bank will be able to yield around 3,700 mAh power. So, you’ll have to decide accordingly.

3. What Size Power Bank Do You Need

If you want to charge a 5,000 mAh phone via power bank, you’ll have to buy one that has over the said amount of power. At the same time, you’ll need to consider other things like the number of charges it can hold.

For example, if you want to charge your Moto G100 several times, consider a 20,000 mAh power backup such as the Anker PowerCore. To put that in perspective, a 20,000 mAh can charge the Samsung Galaxy Z Flip 5 or the iPhone 14 Pro four times.

One of the main disadvantages of a high-power power bank is its weight. They weigh a ton (not literally) and can be difficult to carry around. Apart from that, they are also expensive. But at the same time, they allow you to juice your phone without hunting for a power outlet.

4. What About the Weight of the Power Bank

As noted earlier, the weight of a heavy-duty power bank is considerably more than its mid-sized counterparts. On top of that, they are considerably bigger since they carry the hardware to store the necessary power.

These two are the major limitations of a heavy-duty power bank, especially if you want to use one on the road or traveling. Yep, they are pretty big, but the good news is that all power banks are portable.

That said, there are several new-age power banks like the Anker 737, which has a capacity of 24,000 mAh. Despite its capacity, it has a compact shape and weighs around 1.4 pounds. Besides that, it has USB-C fast charging ports.

Note that conventional heavy-duty power banks take a long time to charge fully. But, with the introduction of USB-C Power Delivery input ports, things have changed in this regard. For example, the Baseus Portable Laptop Charger has a capacity of 30,000 mAh. Still the USB-C input ensures that this massive power bank recharges in under 3 hours provided you use the right power adapter.

5. Power Bank Feature: Fast Charging

Even if you opt for a bigger and heavier power bank, you should check the fast charging capability. After all, you wouldn’t want your smartphone to stay glued to the power bank for hours.

Some power banks, like the Baseus Portable Laptop Charger mentioned above, support USB-C Power Delivery, while others bundle Quick Charge support. These ensure that your compatible phone can charge fast and quickly.

This one ensures that phones like the iPhone or Samsung flagships charge at their required speed, which is true of laptops.

But at the end of the day, it’s up to you to decide if it makes sense to lug a huge power bank with you every time you step out of the house. On the contrary, getting your hands on an efficient wall adapter and a charging cable is a much more clever move. Wall adapters like the Baseus wall chargers can provide up to 65W and are good enough to juice your phone and tablet.

If wall adapters are not your thing, you can opt for a car charger with similar power to provide the necessary muscle to juice your smartphone. Car adapters with USB-C ports efficiently charge smartphones and tablets fast.

Also Read: 4 Best GaN Chargers With Power Delivery for Fast Charging

FAQs About Power Banks

Size vs. Speed vs. Ease

Everyone should indeed have a power bank. They ease your travels and outings. All you need to do is plug them into the device and let the cells inside weave their magic. Sure, carrying a heavy power bank is not the easiest job around.

But if you travel a lot, buying a 20,000 mAh, or 30,000 mAh power bank makes sense. With it, you’ll be able to fuel your phone and more. As long as you remember to charge the device before you hit the bed, you’ll be safe.

However, if you rarely use a power bank and want one just for emergencies, you should get one of the small power banks, such as the INIU Portable Charger. They are affordable and can be easily carried in purses and pockets.