The lumen (symbol: lm) is the unit of the International System of Units to measure the luminous flux, a measure of the light power emitted by the source. The luminous flux of radiant flux difference that the former provides the variable sensitivity of the eye to different wavelengths of light and the latter involves all electromagnetic radiation emitted by the source according Wien law and Stefan-Boltzmann regardless of whether such radiation is visible or not. 1 lm = 1 cd. sr = 1 lx. m2

The battery bank or Power Bank is an ideal solution if you are running out of battery on your device when you really need it.
It's charged using a miniUSB or microUSB cable directly connected to a power source or USB port (PC or MAC).

Its operation is very simple, you only need to connect the battery bank to your smartphone, tablet, MP3, Ipod, etc. and automatically will start charging.

The provided charge to the device depends on the capacity in mAh of the battery bank, usually can perform a full charge of a device and depending on the capacity of the power bank, it can do it a few times.

To calculate the times you can charge your device simply divide the capacity of powerbank between the battery capacity of the device.

Example:
If the battery bank is 7.200mAh i your device is an Apple iPhone, Samsung Galaxy or similar with 1.800mA battery, you can charge up to 4 times without going through the plug.

The charging time of your device using a powerbank is very similar to the charging time using the original charger.

Ideal for long trips, meetings, campsites, etc.