Electronic gadgets of the present age are power hungry. As long as power is supplied, they keep on entertaining us but once power is out, they are simply dead. Nowadays the common man is more concerned with the battery strength of his cellphone. The most irritating thing to see is a Low Battery Notification on your cellphone. Once your cellphone battery is dead a terrifying thought crosses your mind that you could somehow be left alone on some far apart planet without ability to communicate. The inevitable question of others ability to contact you arises. Well having a trustworthy battery for your cellphone is like having a breathing tube in the ocean. Yeah, its a fact! Ones concerns regarding their cellphone battery life when they are using their mobile device for 90 minutes a day increases all the time. This is adding up to 3.9 years of an average human life! Granted, it may be one of the cheapest entertainment sources that you bear in your pocket, but we should keep up its strength as if it were the only entertainment source period.

We all come across situations where our gadgets battery is exhausted after a long journey. Tablets, laptops, portable speakers, headphones and other similar electronics are in common frequent use and need their battery to remain functional. Extensive use causes the battery life to decrease and the battery can drain out in a shorter spell. Without energy, these smart and cool devices are worthless. But modern technology advancements have revolutionized their life, including new trends to keep one stress-free and battery full. Let us introduce you to the power suppliers known as Power Banks that help your devices run longer, keeping your cellphone screens glowing.

What is a Power Bank

A power bank is an external power source that can charge a cellphone or other USB devices. It is a portable device that reserves energy to be supplied when your devices: cellphone, tablet, GPS systems etc. are out of power. Power Banks are available in different sizes, shapes and types that provide you the ultimate energy solution till you get home to a wall charger. It provides a quick boost to your devices battery so that you always remain connected with your loved ones.

You May Need One

When you have to charge your device, you either mount it on a holder, push it in a or a charging transformer hanging on the wall. You also physically have to be near the charger if you want to use your device while its charging. Or if you have to go out for whatever reason, you have to leave the device at your home so that it can continue charging which means you could miss out on some important messages. So power banks are available now to keep you tension-free and charged on the go. Instead of plugging your device into the wall in order to get charged, you can use a power bank that will aid your phone out on the road.

These power banks are available in multiple sizes, starting from a lipstick size (pocket size) to the size of a paper board (to provide power boost for days). 'The paper board' can connect multiple devices on a single module.

Before going on a detailed guide, lets understand some basic terms that will be used further.

Terms You Are Not Familiar With

mAh Rating

Power Banks are mostly recognized on the rating of the battery they bear inside, rated in ampere-hours, and measured in milliamps. The mAh ratings show the power flow rating for specific time.

Li-Ion & Li-Polymer

Lithium-Ion and Lithium-Polymer batteries are the extensively used batteries in Power Banks. Lithium-Ion batteries are cheaper and have limited mAh capacity while Lithium-Polymer cells are a little bit more expensive but are long-lasting. Further details of both are explained in detail below in this article.


You know that full power is never transferred as there are several resistance losses included in the process. So normally a power bank is rated on the basis of the number of spells it takes to fully charge a device. Efficiency is dependent on the size, type and environment in which the power banks are placed. Normal industrial standards of efficiency these days are between 80-90%.

Device Depletion

It is the current status or charging limit of a battery at the time of plug-in. A loss in the charging status means more work has to be done by the power bank to bring it back to life. Normal charging, that is 20% to 90%, is considered full charging as there are several losses included. You can also go from 5% to 100% but that will require more work to be done by the power bank.

Types of Power Banks

Several battery banks are available in the market these days and can be distinguished on different basis. Some common types include:

Universal Power Bank: These are available in several sizes depending on your requirement.

Solar-Charged Power Bank: These include small photovoltaic cell panels that produce power when placed in sunlight. It is a rather slow method of charging.

Old-Chubby Ones: These are the old styled power banks that are designed in the shape of a phone cover and are fixed on the cellphone. These power banks have very limited usage now.

We can also distinguish power banks on the basis of built-in plugs:

Power Card: These are the ones with external charging cables. These are used by most. A USB or charging cable is supplied with the power bank that keeps your device to survive long.

Cable-less: These do not include any external wire. In fact, these are attached to the phone directly into the port via pin, rather USB or other. These are mostly pocket sized.

Choose the Right One

Think First

Here are some common questions that may cross your mind when you think of a power bank. You should ask yourself:

How many electronic gadgets are under my use in daily routine?

Do I have a tablet or a smartphone?

Is there any GPS or navigational module in the gadgets?

What is the total number of each of the items mentioned above?

How often the batteries of the gadgets are exhausted?

Estimate the Power Rating

First you should understand the specifications of your device battery and external battery. Both of the batteries are rated on the basis of mAh i.e. milliamps hour. This should be your guide when selecting the right one. Bring to the frontline all the devices you want to charge with your desired power bank. Lets assume that you have a Samsung Galaxy S6 Edge smartphone and one Apples iPad Air. The S6 battery has a capacity of 3000 mAh and the iPad Air has a reserve battery limit of 11, 000 mAh. Now its time to hate mathematics! We have a simple formula to help you determine the pack size of the battery bank.

Pack Size = Total mAh X % Battery life extension in decimal format

So if you need more power out of your device, you will need a power bank of 6,830 mAh going by the ratings mentioned above. You will need the power bank of exactly the same specifications and ratings as those mentioned on your devices battery. In the situation where you want to power up both the cellphone as well as the iPad, you will need a battery reserve of 14,000 mAh that will inject 100% power to your device.

It is the rule of thumb that more mAh ratings will require a big battery reserve and ultimately, the size of the power bank would need to be on the larger side. Earlier I mentinoed the lipstick sized power bank. It can have just 2000mAh rating or nearer but the idea is to provide a power source that even slips into the pocket and can weigh only a few grams. On the other hand, the 14000mAh battery bank wouldnt be too small to bear in the pocket and might weigh from 2 to 2.5 lbs.

Alternatively, you can have a small one if your devices include just a smartphone. Having a bulky reserve for the sake of powering a smartphone is not a good idea. In fact you are wasting money. But it might be useful if you plan to spend days out on vacation without a proper source.

Current Rating

Current Rating is also a worthy concept, along with capacity, when buying a power bank. Bigger devices require more power and better amperage at the output ports. There are two standard output amperage ratings for the chargers that include 1A and 2.1 A. All the USB chargers can use both the ratings, a 1A battery can be charged on a 2.1A port but it will limit itself to 1A. Similarly a 2.1A battery also filled up on a 1A port but at a much slower rate. The 2.1A port will charge the cells at a faster rate but still, equating the amperage rating of source and load is of much importance. We have another simple formula to convert amperes into watts and vice versa.

Amps = (Wattage) / Voltage

If we have a battery of 5.6W and the standard output voltage from a DC transformer charger is 3.7V then we can calculate the required amperage for the battery as:

Amps = 5.6 / 3.7 = 1.5Ah

These are the assumed values not just for the undeniable hate of mathematics, but to assist you in your purchase. Your device specifications may differ from device to device but the calculation methods are the same.

Output ports

Most of the power banks feature only one port that supplies a 1A current, enough to power your cellphone. But if you need to charge other devices that need excessive power like your iPad then this 1A port is not enough and will not meet the needs you require. So a second port is included that supplies a 2.1A current (devices are now available with more than 2.1A) to strengthen your tablets and other similar devices like headphones, speakers etc.

So you should estimate your devices before you go in for a battery bank solution. This way you will be able to charge multiple devices with accurate ratings. Even if you are camping or on a vacation in another destination, you can share your reserves with your journey mates. Enjoy the voyage!

Brand Name, Build and Cells Used

It would be rather unsafe to buy a power bank from new sellers as there are cases reported in the past where power banks stamped with 10,000mAh were able to produce just 2000mAh. You cannot see whats inside the box so, pay extra, but find a trustworthy company with reputable products.

Li-ion and Li-Polymer Batteries

Lithium-ion batteries use a variety of cathodes and electrolytes. Some common combinations include:

Anode of lithium (Li) ions mixed with carbon or graphite, cathode of lithium cobalt-oxide (LiCoO2).

Lithium manganese-oxide (LiMn2O4) in liquid electrolyte of Li salt.

These batteries are mostly cylindrical in shape due to the liquid electrolyte inside. Prismatic batteries include another and cathode that are inserted into the rectangular enclosure.

Lithium-Ion-Polymer batteries are the next generation of the Li-ion batteries in which the liquid electrolyte is replaced with a plastic polymer. Such assembly suggests multiple sizes and shapes for the battery pack. Li-ion batteries are preferred due to their size, efficiency and power density for specific periods of time. Li-ion provides better timing and advanced shapes compared to the nickel-cadmium or nickel-metal-hydride batteries. Li-ion batteries are light in weight and can be recharged if the battery is not fully drained. This feature excludes the problem of memory handling. Being more efficient and optimized, Li-ion and Li-ion polymer batteries are expensive as compared to the conventionally used cells. This increment I price is due to the volatile nature of Li.

Things to Remember While Buying a Power Bank

Here are some tips that would serve as a reminder when you go for the power bank solution:

Check the device specification and estimate the pack size from the formula equation.

Check your requirement and the power bank size, whether you need a big one or a pocket size.

Check the required accessories, a flash light or a keychain.

Estimate the number of required ports after estimating the number of devices to be powered.

Make sure you get a USB cable, a cover and the adapter to power the device.

Latest Power Banks Available

Several Power Banks are available in market these days. Here we will discuss just a few so that you get an idea.

Solar Power Banks

A solar charger utilizes energy from the sun to power the batteries or supply direct current to the devices. The whole phenomenon is based on photoelectric effect, though we will not discuss in detail but will provide an overview. Solar cells are connected in a series where the upper side of the cell dominates with negative charges while the lower side is the positively charged plate. When the sunlight (or sometimes either fluorescent light) falls on the upper negative plate of the solar cell, photoelectrons are generated that travel to the positive plate and provide a complete current path.

Solar chargers charge the batteries and mostly Ni-Cd batteries are adopted. The same setup is adopted in Solar Power Banks where plates of solar cells supply adequate current. There is an intelligent charge controller in the setup that senses which source (either the direct solar light or the battery) is supplying more power and charges the device accordingly. These power banks can be a single frame or the folding frames. While its incredible that we have access to such a phenomenon as solar power, its important to keep in mind that these power banks are not capable of supplying much power.


These types of solar banks are an advantage for the people who dont have access to electrical supplies for long period of time. Portable Bag packers are also available which fuel the batteries for those fond of hiking being that such batteries are light in weight. Some people prefer solar as it is a good way of living green.

Solar power banks can normally fuel smartphones but sometimes they are also capable of charging the tablets, depending on the requirement as its engine is too weak to supply too much.

You can charge your power bank quicker on a bright sunny day. It doesnt mean that it doesnt work on other days but it is quite efficient on shiny days. Just make sure your device doesnt over heart. A raise in temperature can be a huge detriment to the battery of your phone. You can spot a place that receives the maximum sunlight and then place the solar pack there with plates facing upwards. It could take a few hours to completely charge it, but make sure it receives good light density.

If you are not able to charge the power bank due to insufficient sunlight, you can go for the USB charging mode that normally connects to the computer and charges the battery for your long journey. Remember that your solar power bank is itself an active device that can produce its own power so it will be helpful when you have sufficient light to power it.


This type of solar power bank utilizes sunlight to get charged but if you are living in some area where you face heavy snowfall and less sunlight then dont waste money on this type of product as it is useless for you. This product is only efficient in areas that receive maximum sunlight throughout the year. Parts of a Alaska would be a great bet for this product.

The solar cells are quite brittle and difficult to handle. Make sure that the product you own is shockproof as well.

SunLabz Solar Charger Backpack

SunLabz 7W Solar Backpack enables you to enjoy nature and preserve it. This is a bag featuring solar plates on its face to power up your devices, especially the smartphones during hiking, biking or camping. Its voltage controller is efficient to save your device from over charging. This backpack contains separate compartments that are protected enough to safeguard your device. So whenever you are on a journey, enjoy your travelling without worrying about your smart gadgets. The solar cells, inside weather resistant PVC fabric, provide up to 22% transfer rate with rated 5V that is quite efficient. One can charge a tablet, smartphone, iPod etc. using this portable backpack. It is also contains a bladder with a 1.8L hydration pack and several waterproof compartments. The overall assembly weighs just 3 lbs. (almost 3.52 ounces). It measures 6 x 1 x 6 inches in dimensions (L x W x H).

This Power Bank costs only $79.99 and is available here.

Waterproof Power Banks

Waterproof power banks are shielded with special sheets that protect the inner assembly. So you dont need to get worried if your power banks fall in water because the battery is still unaffected. You can carry your waterproof power bank even in your swimming pool along with your waterproof smartphone (several waterproof cells are available in market and are also listed on our site) so that you dont run out of battery even under water. These are specially made power banks that are certified with IPXX i.e. IP68 or IP69 etc. certifications.

UNIFUN 10400mAh Power Bank

The UNIFUN waterproof power bank is guarded with an IP66 certification which makes it dustproof, shockproof and skid resistance. It is a perfect choice for hikers, campers and travel lovers. It features a 10400mAh fuel tank that can refuel an iPhone 5 times or a Galaxy S4 smartphone three times approximately. Protruding are 2 USB charging cables with 1A and 2.1A rated currents. It features a Li-Polymer battery that provides up to 1000 rechargeable cycles. It is quite power efficient as it turns off automatically when it is not used for some time. It is suitable for charging smartphones including Samsung, Apple, HTC and Google devices including mp3/4 players. It has a strong LED flash light that can glow for a continuous period of 6-8 days untill it is fully drained. It has 4 LED power instructions that consume a different battery level from 0~100 %.

This Power Bank costs only $19.99 and is available on Amazon.

Heavy Duty Laptop Chargers and Car Jumpers

These are the heavy duty power banks that can even charge a laptop and provide a power kick to the dead batteries of cars. These power banks contain some super-efficient Li-Polymer batteries that provide long backup and are capable of providing sudden current doses without dropping its own energy level. They have wider applications so you can run several devices at a time due to its huge fuel tank. These portable power banks can be carried if you are camping and planning to stay for multiple days without access to outlets. Heavy Duty chargers provide bulks of energy. It faces only one disadvantage: it is a little bit bulky, being that it is heavy duty. But in comparison to other available power banks, while it is a little bit on the heavier side, meaning you cannot put it in your pocket easily, it is by far the at the top of the food chain when it comes to power capabilities. But the new modern power boosters are more compact as compared to the conventional ones.

iMedia NY 12V Car Battery Jump Starter

iMedia NY is a multipurpose power bank, Jump Starter & Laptop Charger. It features an Li-Polymer battery that provides up to 1000 recharges. This power bank is a multipurpose charger that can power smartphones, tablets, electronic gadgets, digital cams, wireless headphones, MP3 players and some Laptops. It can even give a power jerk to your dead car battery to start-up your car with a sudden current boost. Above all, it is a heavy duty product that even fits into your pocket. It features a 14,000mAh battery bank that can provide up to 400A peak current and takes just 4-8 hours to get itself fully charged. It also possesses a 3W LED flashlight with 3 instruction modes for emergencies. It is capable of charging four gadgets at a time. You must follow two instructions to use this power bank as a battery jump starter:

Always clip the Black (-) wire to the battery terminal first, followed by attachment of the Red (+) cable and connect the other end of the cable to the small port on the rear side of the power bank.

After successfully installing the cable, start the engine and then remove the cables in reverse order, i.e. remove the Red cable first followed by detachment of Black one.

This Power Bank costs only $119.99 and is available here.

Portable Speaker Entertainer

These power banks bear powerful sound boosters that provide uninterrupted entertainment to make your time memorable. The good thing is that you can carry these in your pocket and take them anywhere you want because of its compact size. Speaker power banks are available in different sizes and several interesting styles. So dont worry if your cars audiotape does not work as it is the best replacement for secured tunes on your long journeys. It can also power up your other power hungry gadgets including smartphones and tabs.

Bienna Portable Bluetooth Speaker & Power Bank

It is a portable Bluetooth speaker power bank that can even power up your smart gadgets including your smartphones and the tablets from a distance of 49.2 ft. It features a 7000mAh battery pack that can provide uninterrupted entertainment for almost 20 hours. It not only bears powerful speakers but also has a microphone to record voice notes. It has also USB and AUX input cables to connect the cellphone and NFC Speakers enabled devices are also connected with the speakers without pairing. It is waterproof, and dustproof so you can carry while hiking and swimming. It is the best companion for the music lovers to kill boredom.

This Power Bank costs only $45.99 and is available on Amazon here.

Outdoor Tech OT4200 Big Turtle Shell

Big turtle shell is a sound boosting power bank that allows you to experience 110 decibels of auditory bliss. It connects with the devices with its powerful 4.0 Bluetooth to provide a continuous powerful audio experience over several feet. It also bears a microphone to record your favorite sounds and external controls making it easy to adjust volume and other essentials according to your mood. It is also waterproof, holding an IPX-5 certification that makes it a well-featured portable power bank at an affordable price. The built-in Li-ion battery can entertain your ears for almost 16 hours and a power outlet is also available to charge other devices like smartphones. You can also enhance your biking experience by mounting it on the handle of your bike. The Big Turtle meshed with soft black color weighs just 8 lbs. Let the turtle float over your mind.

This Power Bank costs only $199.95 and is available on Amazon.

Xtreme X2500 LED Flashlight and Power Bank-2500mAh

This is a portable pocket sized power bank that has a 2500mAh battery pack. A USB cable is available that can charge less-power hungry devices like smartphone and mp3 devices. It has a powerful LED flashlight that makes it more awesome with 3 light instruction modes including the 100%, 50% and strobe brightness modes. This flashlight comes with a key chain and a pocket clip and finds its best use in military operations. It is waterproof and is certified with an IPXX certification. Its the best selection for travelling and camping lovers especially under emergency conditions.

This Power Bank costs only $36.77 and is available on Amazon.

Phone Covers Power Banks

These are very sleek and probably the smallest power banks available in the market. It simply fits to the backside of the smartphone just like a phones cover. It not only beautifies your device but also protects it from scratches. Above all, it contains a small battery that powers the device. These are available in different models and different colors. However, one must ensure that he gets the exact model that fits the device specifically. It only faces one disadvantage, you may not find the exact cover for your smartphone. There are limited models available that are only comparable to certain devices.

Ghostek Nrgsuit - IPhone 6 Protective Case/ Power Bank

Ghostek Nrgsuit is the best option for your iPhone 6 power backup to keep your phone in survival mode so you can remain attached to your contacts for a longer period of time. It is available in three mind-blowing colors that include the meshed black, the crushed Gold and the soft silver. It has a 3100mAh battery bank inside that is almost double the battery of your iPhone so it can power your iPhone almost two additional charges. LED indicators on the face help you monitor the charging and discharging levels. The best thing is that it is certified with a life time warranty and you can claim it anytime you find it faulty. Several frames are available that can be attached according to your mood.

This Power Bank costs only $69.95 and is available here.

Multiple Purpose Power Banks

These power banks are mostly used for charging multiple gadgets like smartphones and tablets simultaneously while using standard USB or Micro USB cables. These are pocket sized and easy to carry and are mostly used to power up smartphones and tablets. However, they are also capable of fueling Bluetooth headphones and mp3/4 players.

Kmashi MP816 10000mAh Battery Pack

Kmashis MP816 battery pack is a mind blowing gadget that has a big tank stored inside to fuel up to 10000mAh. With top specifications and features, this power bank is available at a very low price. It can charge other devices with 5V output voltage. The output ports are rated for 2Aand 2.1A currents. Note that this battery bank doesnt allow charging a device when it is itself charging. It is a totally safe device that offers shielding against short-circuit and over-charging conditions. This device is classic in size and weight and one can even carry it in their jeans.

The Kmashi MP816 power bank hangs with a price tag of just $13.99 and you can catch it here

Anker 2nd Gen Astro E4 13000mAh

E4 power bank offers cool features at its charging ports that can supply a rated 3A current at the output that is even adjustable. The battery is protected inside a drop-proof shell. The button of the LED light protrudes which makes it difficult to slip into your pocket. Moreover, it is not light enough to be kept in pockets.

Anker Astro E4 costs just $29.99 and you can grab this model here.

EC Technology Deluxe External Battery 22400mAh

EC Technology Deluxe is a mega device that supplies power with its 22400mAh capacity battery. It measures 6.3 x 2.9 x 0.8 inches in dimension and is on the larger side making it slightly difficult to carry it everywhere. This mega power bank can provide long-lasting power with its 3 output ports. 3 ports are rated differently that include 2.4A, 2A and 1A output USB ports. As this power bank opts DC output from the cables so you cannot charge a laptop using this power bank.

EC Technology Deluxe hangs with a price tag of $38.99. You can buy this gadget here.

Frequently Asked Questions

What should be the capacity of my Power Bank?

Having a power bank with a capacity slightly above the rated capacity of the battery to be charged is what youre looking for. For example, your cellphone battery at 0% is rated to be 1500mAh and you buy a power bank of 2200mAh then the power bank will pour its power into the battery. However, some of it still remains reserved in the power bank, but your cellphone will be fully charged. On the other hand, a 2200mAh power bank would not be able to fully fuel a battery with a 3000mAh rating as battery requires more to be fully charged. But keep in mind that a 3000mAh can charge a 1500mAh battery twice.

How many Output Ports are suitable?

This really depends upon the amount that needs to be connected. If you merely have to charge a smartphone, you can go for 1 port but for multiple devices at the same time you should opt for a multiple ported power bank.

How to understand the output Specifications?

1A-1.5A output port is generally designed for cellphones, especially smartphones while the 1.5A-2.0A output is meant to fuel the tablets.

How much time it takes to power a power bank?

Keep in mind that a power bank is an active device. The term Active device relates to Electronics Engineering, meaning that it produces its own power. So these devices are already charged and ready to use. The charging time of the power bank depends on the capacity remaining in the power bank and the power supply conceded. The lesser the capacity, the more time it takes to get charged.

Power bank Rating: 13000mAh (0% remaining)

Power Supply/ Input: 1000mA plug

Time = 13000mAh/ 800mA = 16.25 hours

1000-200= 800mAh: shows the power losses while transferring power from one end to the other.

How many times can a power bank charge the phone?

The higher the power rating of your power bank, the more spells it provides to charge the device. You can do simple calculations to estimate the number of times it can fuel you device.

Power bank rating: 10000mAh (full at 90%)

Phone Battery rating: 1500mAh

Charging spells: (10000mAh x 90% x 80%) / 1500mAh = up to 5 times

As mentioned in the start, a good power bank can give out up to 90% while 80% portrays the power left behind after excluding the power losses.

Why is my Power bank not properly charging my tablet?

Tablets normally use a 2.1A port to get charged while some power banks include only one port i.e. of 1A. It charges the tablet but at a slower rate. Try to grab a power bank with a 2.1A port. Another factor could be the USB cable. Make sure your cable is specific to your device.

Why do Power Banks tire so soon?

A power bank is capable of returning 0-90% of its original capacity. Might be that the power bank is smaller to keep your device alive. Read the specifications of your devices battery briefly. Also perform the calculations suggested earlier in this article to know the number of spells it provides to charge up your device. TIP: Disconnect the USB cable when not in use.

Why wont my power bank startup?

Its quite possible that the power bank itself is power hungry. Connect it to the supply so the blinking Led can show that it is connected. Power banks also switch to sleep mode when they are not in use for some time. So turn it on again to wake it up!

How long do the Power Banks survive?

A power bank gives out 80-90% of its stored power and can survive for 400-500 charge/discharge cycles (where 1 charge+ 1 discharge = 1 cycle). If a power bank doesnt store enough power to provide a backup, throw it out and go for a new one.

Different power banks with different output specifications are available on the market. Some companies focus on the capacity rating (mAh) and some excel in output amperage and number of ports. One should go for the best solution after estimating the requirements and knowing his/her needs.