USB Chargers

Posted by: ConRAD

USB Chargers - 05/11/18 10:31 AM

First of all thanks to Fahrradzukunft [https://fahrradzukunft.de/] for having published and so far shared all the below charts and information.
Said that, due to my very poor German knowledge, I’d appreciate if someone could help me in German to English translation and possibly confirm my “Highlights&Conclusions”
Thank you in advance.



LEGEND
- Ladesleistung in die Akku-zellen = battery charging power [W]
- Fahrgeschwindigkeit = speed [km/h], all data based on SON28 assembled on a 28” wheel
HIGHLIGHTS&CONCLUSIONS: with some models at 20 km/h it seems to be possible to have up to 5.5W charging power to the internal buffer battery


LEGEND
- Max Dauerhafte USB-Leistung = max permanent power at USB output [W]
- Fahrgeschwindigkeit = speed [km/h], all data based on SON28 assembled on a 28” wheel
HIGHLIGHTS&CONCLUSIONS: with some models at 20 km/h it seems to be possible to have up to 5.0W permanent power at USB output


LEGEND
- Wirkungsgrad Akku zu USB = efficiency power_battery/power_USB [%]
- Entnahmeleistung am - USB-Anschluss = power on USB output [W]
HIGHLIGHTS&CONCLUSIONS: with some models at 3W USB output it seems to be possible to reach up to 84% efficiency (QUESTION: is efficiency to be intended as overall efficiency, i.e. dynamo to USB output, or just internal buffer battery to output ???)


LEGEND
- Fahrgeschwindigkeit = speed [km/h], all data based on SON28 assembled on a 28” wheel
- Electrische Leistung Dynamo = dynamo electrical power [W]
HIGHLIGHTS&CONCLUSIONS: with some models at 20 km/h it seems to be possible to have up to 6.5W transferred power from the dynamo to the charger
Posted by: maram

Re: USB Chargers - 07/07/18 09:16 AM

Originally Posted By: ConRAD
(QUESTION: is efficiency to be intended as overall efficiency, i.e. dynamo to USB output, or just internal buffer battery to output ???)

If you look on Steckdose unterwegs (http://fz.0x0c.de/11/steckdose-unterwegs/) you will see that this is the efficiency from the output of the battery battery to USB, that is, how hot is the voltage converter becoming...
Posted by: ConRAD

Re: USB Chargers - 07/09/18 08:03 AM

Very clear, thank you.
Posted by: ConRAD

Re: USB Chargers - 05/24/19 09:37 AM

With reference to "e-werk" and looking at the below specific plot, I've a question:

QUESTION: is the e-werk output power referred to a specific e-werk output voltage, i.e. is the output power at 20km/h allover the same from 2.8V to 13.3V?

The reason I ask it is because, just to make an example, at 5.6V I get more then 3W.

Thank you for any reply.

According to the Forum Rules, only own pictures, texts, etc. may be shown in posts. Therefore, I had to give a link for this picture (fortunately, I know from where it was taken).

Figure taken from "Fahrradzukunft"