When I do a tour, the battery lasts about three hours according to experience, depending on which applications are running and how often I turn on the display. Usually runs at least through GPS and the mobile Internet, often even Bluetooth to let me navigate through headphones. All this consumes power. If it would now be possible to extend the three hours that would be a significant increase of pleasure while cycling.
The installation of the E-Werk myself I hammer out quite quickly as a bicycle-layman, what is not least that the product is accompanied by a wide selection of cables and adapters. My Shimano hub dynamo (a hub dynamo is a prerequisite) has a plug that is supplied from where the headlights with power on the side. The charging cable of the E-Werk is now with the cable of the headlight twisted (= twisted) and re-set in the plug. This sounds more complicated than it is. The e-work itself, I have secured with the supplied (in three sizes) elastic bands to my frame and the cable there tightened with cable ties. Rubber rings make the impression that they would not hold too long, if you often solves the E-Werk from the frame. As far as the assembly.
The function test was, however, disappointing and disappointing. I could not detect any longer battery life and the reason for this is opened up to me pretty quickly if I put a charger in my HTC One S, the display comes on. The lights normally be at least 15 seconds (minimum value) before it goes out again. But if the power plant is used as a battery charger, the current flows from there with fluctuations in the smartphone. Current flows for about 3 seconds, as long breaks from and then flows back, etc. The consequence of this is that the smartphone every three seconds gets the pulse that a charger is connected ... and the display lights up for 15 seconds. So it is clear throughout the whole time. Even if you turn off it manually, it will light after a few seconds on again. It may be that other smartphones behave differently here.
At first I was looking for an app that suppresses switching on the display during charging, but this has not been able to find. In the default settings of the smartphone I found also nothing suitable. Before purchasing the E-Werk but I had read that it would (also from Busch & Müller) provide for such cases a buffer battery. This is connected between the power station and the smartphone so that it initially collects the flow of e-work and fluctuation free passes on the smartphone. Cost, however: just under 45 euros. This I bought and have no more problems now (see my review here).
Conclusion: The E-factory alone was useless to me. Only by the additional investment in the buffer battery is now working as I expected beforehand or exceeds my expectations, it even. Because the E-Werk causes not only that the smartphone will discharge more slowly or holding the battery level, it even loads still on and I end up the bike a higher battery level as at the beginning! Nevertheless, one should be aware before buying the fact that may still result in additional costs for the buffer battery.
E-Werk alone: 1 Star
E-Werk with buffer battery: 5 stars
Overall: 3 stars