Power banks have become an important everyday carry gear nowadays. This is because even though smartphone technology has improved at breakneck speed during the last few years, the battery technology that powers these smartphones have not been able to keep pace.
Result? More and more people are going for portable battery chargers or power banks, as a backup for their ever-increasing smartphone usage. And this has resulted in the market being flooded with power banks, making it all the more difficult to choose one. However, just following these simple steps, you will be able to find a power that fits all your needs as well as carry it everywhere comfortably.
1. The Capacity and Efficiency of the Power Bank
How much capacity do you really need in a power bank?
The capacity of a power bank is a measure of how much charge it can hold. It is measured in mAh (Milli Ampere Hour). The more the mAh, the more number of times you will be able to charge your smartphone.
That does mean getting a power bank with the maximum mAh rating will be a good idea, right? You will find power banks starting from 5000 mAh going all the way above 20000 mAh. But just think about it, do you really need all that capacity?
Most smartphones nowadays have batteries that typically last a day, somewhere in the range of 4000-5000 mAh. In case you are a heavy user and your phone runs out of juice in the middle of the day, you will most probably need to recharge it once. So for most people, the ideal capacity would be something that is able to completely recharge the phone at least once.
So what should be the ideal capacity for a power bank, if you have a smartphone with, say, a 5000 mAh battery? It should be a power bank with a rated capacity of at least 5000 mAh, isn’t it?
Hold on, here comes some technical information that everyone buying a power bank should know about.
The rated capacity, that is, the capacity you see printed on the power bank and in the catalog, and the real capacity that the power bank will actually deliver, are not the same. Why? Because the conversion circuit inside the power bank and the internal resistance in the USB power cable will eat up some of the charge.
No power bank is immune to this loss. Even for the best power banks, you can expect around 75% of the rated capacity as the actual capacity. Since you do not know before buying how efficient the power bank is, to be on the safe side, a good rule of thumb is to consider 2/3 rd of the rated capacity of the power bank as the actual capacity.
Just by remembering this formula, you will avoid a lot of confusion and future frustrations after buying a power bank.
So to completely charge a 5000 mAh smartphone, we will need a power bank that is rated at least 7500 mAh, or more.
However, some of us also like to carry other electronics items like Bluetooth headset, Bluetooth selfie stick, action camera, etc. along with us wherever we go. If you are such a person, it will be a good idea to consider a power bank capable of recharging those items too along with your smartphone.
In that case, a power bank with a rated capacity of around 10000 mAh would be an ideal choice. Again, if you are the digital nomad type, your requirements may be huge, and you will probably need something bigger to power all your gadgets, or even multiple power banks to satisfy your needs.
Moreover, while choosing the capacity, do keep one point in mind. Power banks are usually not allowed inside checked luggage in flights, and hence have to be carried along with you in your carry-on bag or luggage inside the flight cabin. Also, most flights have restrictions on the maximum capacity of power banks you can carry along with you. This maximum capacity ranges somewhere around 20000-25000 mAh in total.
Usually, these restrictions are not enforced very strictly. I once managed to carry along two power banks in a flight, one of 20000 mAh, and the other 10000 mAh. But if you are doing so, you should also be prepared for your power bank(s) to be confiscated by the airport security personnel.
2. Portability: Does it Fit in Your Pocket?
A thing that you are supposed to carry every day with you should be small and light, and power banks are no exception. A large power bank may give you that added capacity, but it will also be larger in size causing portability issues.
In fact, for EDC (everyday carry), you should consider a power bank that can fit in your pocket comfortably.
Have you ever used your smartphone while charging it with a power bank? If you have, you already know how difficult it is to hold the phone and the power bank at the same time, along with the messy USB cable connecting the two. Try doing this with a massive 20000 mAh power bank and you will understand what I mean. I recently did this in a flight, and in an hour my hand was paining like hell. A small power bank is so much comfortable and manageable in such situations.
If you carry your power bank in a bag, a small power bank will reduce the weight, as well as free up some valuable real estate in your EDC bag to make room for other necessary items.
Even for similar capacity, power banks come in different sizes, shapes, and weights. You should look around for one that has the ideal capacity you need in the smallest package possible.
3. The Speed at Which the Power Bank Charges a Phone (and Recharges Itself)
Most of us use a power bank while we are outside and our phone has run out of juice, and we need the phone up and running as soon as possible. Are we going to wait forever in such situations for our power bank to recharge our smartphone? Of course not, and that is why the speed at which the power bank recharges our smartphone is very important.
The charging speed depends on how many Watts the charger can pump into the smartphone. It is not directly printed on the power bank, but it can be easily calculated by multiplying the output voltage (V) and Current (A) rating. So if a power bank delivers 5V at 2A, its power rating is 10 Watt.
You might have heard of, or might be even using, some smartphones that can be charged completely in 30 mins or 1 hour with the wall charger supplied by the manufacturer. Some technologies like VOOC (by Oppo), or SuperCharge (by Huawei) can do exactly that. But such technologies are proprietary and are not available in power banks.
However, there are two fast-charging technologies that can be licensed, and hence are available in some power banks as well. These are Quick Charge (QC) and USB Power Delivery (or USB-PD).
Quick Charge is currently in version 4 (QC 4.0). While QC 4.0 is not available in power banks yet, you will find a lot of power banks compatible with Quick Charge 3.0. Similarly, a lot of power banks also support USB-PD. QC 3.0 can charge devices at 18 Watt. USB-PD charging speeds can theoretically go up to 100 Watt. However, the maximum you can find in the current generation of power banks is 18 Watt.
Do note that to utilize Quick Charge or USB-PD in the power bank, your smartphone should also be compatible with such fast charging technologies. Otherwise, your smartphone will just charge at the normal speed, even if the power bank supports fast charging.
Most power banks available in the market charge at 10 Watts. Even if the marketing information says that it supports fast charging, do not believe it until you see Quick Charge, or USB-PD specifically mentioned. If your smartphone is compatible with it, always go for a power bank that supports QC or USB-PD. You will thank yourself later, as the difference in the charging speed is significant.
No matter what power bank you choose, if you do not use good USB cables while charging your devices, it will considerably slow down the charging speed.
In most cases, the best USB cable to use for charging would be the one that came along with your smartphone, or along with the power bank itself.
However, sometimes companies do provide low-quality cables to keep costs under control. If you suspect that your devices are not charging as fast as they are capable of, you may buy a high-end USB cable from the market and use it with your phones and power banks. Believe me, you will notice the difference.
Another point to note is how fast the power bank itself charges completely. You will usually be charging the power bank at night, and take it with you while going out in the morning. Usually, 6-8 hours is enough to charge a power bank from 0 to 100%. But some high capacity power banks may take a long time to recharge itself.
In this case, it is helpful if the power bank can use fast charging technology while recharging too. USB-PD compatible power banks usually have this feature, as the USB-PD specification supports the bidirectional flow of current. You can almost reduce the power bank recharging time by half using USB-PD.
4. Charging Options: Number and Type of Ports
All power banks will have at least one USB output port and one micro USB input port. In case you want to charge multiple devices simultaneously, look for one that has more than one output port.
If the power bank supports QC 3.0, the USB output port also needs to be QC 3.0 compatible to deliver fast charging. Then you should look for a power bank that has multiple USB ports all capable of QC 3.0 charging.
In case the power bank is USB-PD compatible, then it will have a USB Type C port. The best thing about a USB-PD compatible power bank is that it can charge other devices, and also recharge itself through a USB Type C port that is compatible with USB-PD.
How do you know whether the port supports QC 3.0 or USB-PD? In most cases, it will be marked as such at the port itself. Just look closely, you will see the QC3.0 logo or USB-PD markings near the port. Sometimes, USB ports that support QC 3.0 are of a different color. Again sometimes, 18 Watt is written just below or above the port to indicate that it can fast-charge at 18 watts.
You can also consult the catalog that came with the charger and read the full specifications of the Power Bank to ensure whether it supports fast charging.
Some power banks come with multiple QC 3.0 USB output ports, micro USB input port, as well as USB-PD type C input/output port. This can give you a lot of flexibility while charging your devices, as well as recharging the power bank itself.
5. Good Brand Usually Means Good Quality
Smartphones have made power banks so popular that almost every electronic/electrical company has started making power banks to get a pie of the market. And not all of these companies have great quality control.
You can get a good power bank from an unknown company, but you just can’t be sure how good it is until you use it. Bad power banks are known to damage smartphones, leak liquids and even explode. Though such extreme cases of power banks exploding are rare, but they do exist.
Some companies use refurbished batteries in power banks to keep the cost low. These affect the longevity of the power bank. The casing of the power bank should be robust enough to withstand minor wear and tear, as well as the heat generated by the conversion circuit inside the power bank.
Well-known established brands usually use higher quality material and components which makes the power bank more durable and reliable.
Don’t get me wrong, there are a lot of little known brands/companies that are probably making good power banks. But you just can’t be sure. Smartphones are costly gadgets, and it is always better to use reliable power banks from well-known brands to recharge your smartphone. A brand that has been in the market for long should be preferred over something that has been introduced recently in the market.
6. Additional Features are Good to Have
Some power banks come with other features like LED flashlight, Pass-through charging, Wireless Charging, Solar charging, etc. These features are not very important for the day-to-day use of a power bank, hence analyze your requirements before you opt for these features.
LED flashlight sometimes comes in handy, but the torch in your smartphone can do the job. Pass-through charging allows the power bank to recharge itself, and at the same time charge another device. This may be useful in certain situations, but do not choose a power bank only based on this feature, as you may not be using this much.
Wireless charging is cool, but your phone needs to be compatible, and it is slower than wired charging. Solar charging power banks have photovoltaic panels to recharge the cells inside the power bank. This may sound cool, but the process is slow hence such power banks usually are of very low capacity.
In short, if these features are not very important for your type of usage, just ignore them.
7. Cost of the Power Bank
Are good power banks available at a cheap price? Well, it depends on what you consider as good. If you just want something to get you by when your smartphone runs out of juice, probably any power bank will do the job. If you really want something that fulfills all your diverse needs, and portable enough to be an EDC, then it may not be the cheapest option in the market.
However, if you are faced with the option of choosing one from two power banks which basically fulfill all your criteria, then, of course, go for the cheaper one.
A good portable power bank is a super useful device that in many cases will outlive your smartphone. For me, quality is king in power banks. I had one that lasted almost 6 years before it started showing its age and could not retain its full charge anymore. If I am assured that a new power bank will last that long, I will happily go for it even if it is a bit costly than other available options in the market.