Power Bank in the practical test processing, operation and capacity

Who wants to the way time charge, will be able to use this spare battery well

Packing:
The spare battery is supplied in a customer-friendly packaging. The packaging is easy to open and unaided. It comes with the spare battery, a USB charging cable and an English manual.

Processing:
Modern housing is immediately positive effect on: The white plastic looks very high and noble. The surface feels pleasant, everything is rounded, there are no sharp edges or corners. The case is processed very robust and stable. Both USB ports are precisely; USB connector can be plugged easily and pull out again.

The battery is already preloaded, so I can try it out immediately and charge my iPhone.

Weight and size:
With 420 g of the spare battery is not one of the lightweights, the high capacity, the high weight, however, is absolutely justified. Who wants it more easily, has to save at full capacity.
Low weight means low capacity in counter stuff.
The external dimensions of approximately 14cm x 7cm x 2.8cm make the battery handy and not too big. The battery fits into any small bag or backpack enough space. For the pocket but this is not suitable.

Operation and Instructions:
The operation is very simple and self-explanatory; without manual I was able to connect and charge my iPhone. Still, I've read through the English manual; this has a very comprehensive and clear. All necessary information is available.

On the front of the chassis to 4 white LEDs, a pushbutton, the charging socket and 2 USB output sockets located with 5V / 2.4A and 5V / 1.0A output current. The 4 LEDs indicate the charge level in the form of a scale with 25% each. The switch is needed to check the current battery level.

Charging:
The included USB cable is 30cm long; so that the battery can be recharged when needed. Charging is indicated by a plurality of white LEDs on the front of the chassis; when the battery is completely full charged, all 4 LEDs.

Note 1:
To charge the battery, a USB charger is required. This should min. Can provide 2 amps output current, only the battery is within 12-16 hours fully charged.. For chargers with less output current can take sometimes more than 20 hours to complete a full charge.

Note 2:
The charging of the auxiliary battery is also dependent on the used USB charging cable. Here, the processing and the cable cross-section play a major role within the cable. A low-quality USB cable provides less charging current than a high-quality USB cable. For this reason, the included USB charging cable here should always be used.

Capacity:
According to the manufacturer of these spare battery has a capacity of 20000mAh.
On the issue of capacity I go below a more detail.

Especially practical:
There are 2 USB Charging Ports, thus 2 devices can be charged simultaneously. I take this to charge my iPhone and my iPad at the same time.

Conclusion:
This spare battery is robust and easy to handle. The capacity is sufficient for diverse devices to charge several times. This allows the standby time, the move also without power, be significantly extended.

I am totally satisfied with this spare battery.

Strong buy recommendation

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Additional information relating to capacity:

Practice Test How much capacity is actually there?

The most important criterion when buying a Power Bank is the specified capacity. More capacity means more energy and hence a longer endurance. But what is actually behind the different capacity to the manufacturer? In order to shed some light into the darkness, I occupied myself more intensively with the issue and would like to pass my findings.

This Poweradd Power Bank has according to manufacturer a capacity of 20000mAh. This statement sounds good at first, but does not really help further since the battery rated voltage is not specified. The nominal battery voltage must not be confused with the 5V output voltage at the USB port. The battery rated voltage is 5V no means, but in most cases the built-in lithium-ion rechargeable has a nominal voltage of 3.7V.

First, the maximum available in the battery energy in the form of watt-hours (Wh) has to be calculated:
Battery Voltage * Capacity = Energy in Wh
* 3.7V 20000mAh = 74 Wh
This value is, in comparison, the bottom of this Power Bank.

"Wh 74 indicates the power that can be abgebeben maximum within an hour."

The Power Bank provides an output voltage of 5V is available, therefore must be an internal voltage regulator, the battery rated voltage of 3.7V to 5V converter. Now it will be exciting, because the specified capacity of 20000mAh is only available with 3.7V. The actual available capacity must be recalculated at an output voltage of 5 V:

Energy in Wh / output voltage = Calculated capacity
74 Wh / 5V = 14800mAh

Theoretically has this power bank so on exactly 14800mAh.
Using a suitable measuring instrument I have performed on this PowerBank a capacity test and was unable to determine a capacity of exactly 15005mAh. The tension remained constant during the test at 4,92V (see photo).

A measured capacity of 15005mAh is an outstanding value for that battery, because mathematically should only 14800mAh available. Usually occur in the voltage conversion (3.7V to 5V), additional losses of about 10%. This is not the case for this battery.

This test demonstrates that this is a really good, high-quality power bank.

With a meter, I have checked the output currents stated:

The USB output with 5V / 2.4A supplies the specified current of 2.4 amperes, the voltage remains stable at 4.87 volts.

The USB output with 5V / 1A supplies the specified current of 1.0 amperes, the voltage remains stable at close to 5 volts.

After various tests, I found that this procedure is so common with most manufacturers. It is always given the nominal capacity of the built-in battery. The actual capacity which is available at the 5V output is not specified.

Conclusion:
The stated capacity of the producers of Power benches are absolutely right, but always refer to the internal built-in battery with a rated voltage of 3.7V. By the voltage conversion to 5V, the available capacity is much lower.

"Nominal capacity is the actual capacity"