Still more
It's the credo of manufacturers (and consumers) about the batteries of smartphones, and seen its consumption by our electrical devices like smartphones and tablets, it spits on it. But who says greater capacity, said a longer time to reload. And at this level, external batteries that are late.
About external batteries
External batteries have mainly 3 important characteristics:
- the capacity
- the incoming intensity
- the outgoing intensity
- the number of output ports
The ability to do this, this varies greatly, you which charge barely 1/4 the battery of your smartphone (cases of extreme urgency and which is typically located in credit card format), other half, others, virtually the entire battery (about 2000mAh), and finally those who have more capacity than that of your smartphone and Tablet and you can recharge several times (generally (, + 5 000mAh). The incoming intensity, is what allows to charge the external battery, she is great, and more it is able to recharge faster. Classically, it is from 0.8 to 1 A. Outgoing intensity, of course, the opposite and it is what will in part determine the speed of reloading of your device. Currently, at the level of smartphones, the incoming intensity of these devices is 1 or 2.1 A. The 2.1 have found predominantly in high-end smartphones and tablets. The speed of the device to reload reloading is of course limited by the lowest value: If your battery is able to get out of the 2 but that the smartphone is capable of receiving 1, this will be 1 was due out of the external battery. The number of USB ports to output: generally 1 or 2. And when this number is 2, either, you have 2 ports to 1 A output, either you have 1 port 1 has output and the other at 2, 1 has. Bottom bar contacted me to test one of their product: the 20.000mAh external battery (which is huge), but not only have a huge capacity, the incoming intensity is 2A (which is very rare!), and that is not all, 2 output ports are also 2.4 A, which is also rare! I haven't checked, but all these rarities would almost make it a unique external battery of its kind! In any case, all external batteries which I could see gender passing, none had these characteristics. 
The characteristics
- Capacity: 20000mAh
- Incoming intensity: 2A
- Outgoing intensity: 2 x 2.4
- Outgoing number of USB ports: 2
- Ignition button
- Integrated LED torch lamp
- Built-in load level
- Dimensions: 16.2 x 7, 4 x 2.2 cm
- Weight: 400 g
- Operating temperature: 10-45 ° C
- The supplied cable length: 50cm
The test
As expected, the battery is similarly impressive: almost 500gr and 16cm long, it does not go unnoticed. Entirely white with a gray stripe to the level of the slice, the design is simple. 
This battery has so 2 ports USB 2.4 output, a mini-USB port for charging (cable and AC adapter included) and a white LED lamp. To turn on the LED, just quickly press 2 times on the ignition button. The incoming intensity level, the measured intensity is 1.83 Å instead of 2A, but taking into account the usual margin of error of 10%, the account is good. 
On the other hand, at the level of the adapter which is supposed to give 2A, it can easily give 2.5 A at the level of the USB ports of exit, I unfortunately failed to reach the 2.4 A, but this isn't a lack of battery, but a lack of accessories as i recharges in 2A (more difficult to reach 2.4 with 2 devices that recharge only with 1 A max each), but one thing is, is that the 2A are well met. You also have 4 blue LEDs that indicate you the level of charge of the battery, by 25%. Through these 20000mAh, once recharged, you are quiet for a good long while: you what charge about 10 times a smartphone (so what take 1 week if you charge 1 time per day!)
Conclusion
An excellent battery with high capacity! Not only to have a huge capacity, it can recharge and reload quickly thanks to its intensity from 2 to max and out of 2.4 A! The product link: http://www.amazon.fr/gp/product/B00RYXUEES/