What is a Power Bank?
A Power Bank is a portable lithium battery pack with a 5V 1A and or 2A (usually, or sometimes 500mA in very small devices) USB output for charging mobile phones, digital cameras, MP3, MP4 players, iPods, iPads, tablet, satellite phones or any product that can be charged from standard USB 5V charging technology. You can also get other voltage versions for powering other types of products with DC outputs from 5V up to 24V. For laptops etc.
What will a Power Bank Charge/Power?
In general the majority are USB chargers, so any USB powered device.
How do they work?
They have microprocessor controlled circuitry to control charge voltage & current to the 3.7V lithium batteries which are either cylindrical lithium ion or low profile Lithium polymer. There is also a step up DC-DC converter to boost the battery voltage up to the 5V output for the USB output. Protection circuits are there to prevent over charging, over discharging, over voltage, short circuit, over current and overheating.
How do I connect my device to the Power Bank?
Couldn’t be simpler! For charging you use the USB lead supplied with the charger and plug the large USB connector into the output socket of a standard USB AC-DC charger or a PC and the micro USB charger into the power bank. If you don’t have a phone charger that has a USB socket but has a flying lead output then you will almost certainly have a micro USB terminated on the other end of the lead. Simply plug the micro USB connector in the power bank to charge. It doesn’t matter whether you plug the power bank into a 1A or 2A USB charger as it will only take the current required to charge its internal battery. You cannot over charge. For charging your mobile device simple plug the large USB socket into your power bank and the other end into your mobile device. This will either be a micro USB connector, iPhone or mini USB.
Inside is a microprocessor control PCB with fuel gauge to show the charge level of batteries and the Lithium batteries, some versions feature an LED torch, and some have a built in solar panel to charge from the sun.
Why do I need one?
Anyone who has a mobile smart phone needs one of these! Especially if they are used a lot for web browsing, emails etc.
How long does a Power Bank take to charge?
This depend on two things, the size of the batteries and the rating of the charging circuit within the power bank. This could be from 500mA on some small capacity products up to 2A max for larger units (max USB output)
In general small units may take 3-4 hours and high capacity ones up to 15 to 18 hours.
How many times will a Power Bank charge my device?
This depends on the capacity of the Power Bank and the device being charged. Fully charged smaller Power Banks will charge a Smartphone once while larger capacity models will charge a Smartphone up to five times and a tablet twice.
How long will it stay charged if I don’t use it?
Should last quite a long time. A lithium battery should last a good two or three months but it depends on the design of the power bank and how much drain is on the battery from the internal circuitry. They should certainly last long enough for anyone to use them for charging their phone over a week or two or more.
I have several Power Banks, how do I charge more than one Power Bank at a time?
We have a variety of mains powered USB chargers that can charge 1, 2, or 10 devices simultaneously. The devices you charge with these can be Power Banks, mobile phones, tablets, and most other USB devices.