With the evolution of smart phones there have been numerous articles on how to reduce battery drainage, what apps on your phone drains your battery faster, so on and so forth. At the end of the day it always comes down to the battery. What bullets are to guns, battery is to your smart phone. This small device which possesses the power to convert chemical energy to electric energy gives your smart phone POWER and quoting Spiderman "With great power comes great responsibility."

What we are trying to say is, these rechargeable batteries, without which we are socially impaired in today's world are an important device in our smart phone. Since we cannot tune out the apps (to save on battery), which make smart phones smart, we can always resort to using portable USB battery chargers or Power Banks. Our duty lies in selecting the right device for our phones and how powerful the Power Bank is.

Smart Phone users are rapidly gravitating towards Power Banks because they are portable and can be easily charged with the phone charger, computer USB port and chargers supplemented by the device as well. For the more ecologically inclined crowd there are also Solar powered Power banks.

These rechargeable batteries of Power Banks are made up of Lithium ion and their capacity is measured in Milliampere-hour (mAh), though these terms tend to intimidate us, but these are very basic and simple qualities that we need to understand before we delve into measuring the power of our portable USB chargers.

Milliampere-hour (mAh) is nothing but a thousandth of an ampere hour, which is a unit of electric charge, equal to the charge transferred by a steady current of one ampere flowing for one hour.

Since the Power Bank stores power in the form of DC current, it clearly charges your Smart Phones much faster compared to AC chargers a.k.a the Smart Phone chargers which accompany your Phone, reason being these AC chargers because they transfer AC current to DC, the flow of current is not steady, thus takes longer to charge than a Power Bank which charges your phone with its DC output and with its steady flow charges your devices much more efficiently and faster.

It is a myth when some Power Bank companies claim that their products provide a 92%mAh conversion. Conversion rate is the remaining capacity of the battery after some part of it is lost in heat or PCB. This 92%mAh conversion claim is not possible because the conversion rates of the batteries depend on the input voltage and energy dissipation as pointed out earlier, because of which the same portable USB charger will charge faster through a phone charger but takes a longer time to charge through a computer USB port. In reality conversion rates produced by Lithium ion batteries is only 75% to 80%.

When we consider the power of a Power bank, we must take into account the Real capacity of their batteries, for instance, if a portable USB charger with a 10000mAh (Real Capacity) claims to charge your Samsung S5 with a battery capacity of 2800 mAh up to 5 times, then it is not a justified claim because considering an average conversion rate of 80% of the its battery, if we apply this simple formula we get to know that in reality the device with its real capacity of 10000mAh can only charge the phone up to 2 times.

REAL CAPACITY * conversion rate * phone battery health / phone capacity = total charge times

EXAMPLE:10000 x 0.8 x 0.8 / 2800= 2.28(approx 2 times)

When deciding on a Power Bank we also need to see if the same comes with an Electric Circuit Protection which will protect your Smart phones from overcharge, Over-Current, Over-Discharge and Short-Circuit. Electric circuit protection cuts off the power supply once your phone is completely charged, its absence leads to reverse current from the device, which in turn will harm your phone/tablet/MP3 player.

Always buy a portable USB charger with a Lithium Ion battery though they are expensive but are much safer because they generate less heat, the battery capacity is durable and they come with a battery protection circuit, as mentioned earlier which protects your smart phone from overcharging and short-circuit.

So be smart and powerful with the Power Bank, choose the right one and enjoy your smart phone without being Powerless.

Ravin Kumar is the communications manager for Ravin Retail. Ravin Retail Energy Products comprise of three categories namely: Power Banks, Solar chargers and Solar Lanterns which provide a smart and convenient new way to charge smart phones, Tablets, iPads and MP3 players.