2.10 – Intenso Power Bank

Power banks mainly provide our smartphones with energy while traveling. They can also be used for all kinds of electronic projects when it comes to standalone devices.

For our particular application we have a few requirements:

  • well-known brand so it can be ordered from hopefully anywhere in the world
  • compact size
  • suitable connector arrangement
  • high charging/discharging current (well relatively)
  • charge while discharging (allows an operation while plugged in)

Without going into detail, I tried out four different products and every single one had its problems (mainly charging while discharging).

My final choice is the Intenso power bank 7332530 with a capacity of 10,000mAh. The outer dimensions are 130mm x 70mm x 15mm.

It can be charged and discharged with a maximum current of 2.1A which is sufficient for our purpose. The battery can also be charged while the output is in use. Unfortunately, the power is disconnected internally at the very moment you pull out the charging cable. This leads to a power loss for maybe a tenth of a second which could be buffered with a capacitor, so the power bank may be used as a UPS as well. I haven’t done that. Instead I live with the disadvantage. In almost two years of usage, this has never been a problem.

10Ah at 3.7V (37Wh) and an estimated step-up efficiency of not less than 90% result in at least 6.5Ah at 5V.

When booting, the Pi Zero W consumes something between 160mA and 210mA in the stock configuration. Idling with connected WIFI draws about 160mA. This value doesn’t change when connected via SSH while doing nothing. Executing the program yes increases the power consumption to 230mA. It rises even more when listening to loud music with mpg123 (400mA). Running the LED rainbow snake test program doesn’t have such a big influence (210mA). Summed up, the battery pack offers more than enough juice to power our device for several hours of continuous usage.

In contrast to other power banks where you have to push a button, the Intenso provides power as soon as a load is applied. Moreover, it has a nice band of mini LEDs to indicate the battery status. If not used for a minute or so, the lights will automatically turn off.

The chosen battery has two more particular upsides in comparison to other models that I’ve tested, which is the alignment of its connectors. On the one hand, it provides a flat and flexible Micro USB ribbon cable. On the other hand, the charging port is placed on the corner in a space-saving way.

I am very satisfied with my choice.