E-WERK set up

[iainwarner]

Hi I have a product called a Busch and Müller E-WERK it's a Bike-mobile hub dynamo powered supply unit for electronic devices.
I want to charge my Rav Power bank Ace series as im riding.
Model RP-PB052
Capacity 22000mAh/83.6Wh
Input DC 5V/2.4A Max
Output (smart) DC 5V/5.8A total
Please could you help me with how I should have the E-WERK set up.
It has OUTPUT VOLTAGE Adjustable from 2.8 V to 13.3 V - in steps of 0.7 V (this way, mobile devices can be powered/charged that are run by 1 to 3 serial Li cells or 2 to 9 serial NiCd/NiMH cells). The integrated voltage converter prevents the voltage created by the hub dynamo (depending on speed) from exceeding the set value.
OUTPUT CURRENT Adjustable from 0.1 A to 1.5 A in steps of 0.1 A.
Thank you for your time Iain

[Tigerbiten]

As the E-werks doesn't output exactly 5V then you either need to run it slightly under/over that voltage.
It's probably safer to start slightly under, I think it's 4.8 volts, and see how well it charges your battery/devices.
If it charges well then leave it at that, if not then turn it up one notch to just over 5v.
I've found that cheap chinese cache batteries don't like running slightly over 5 volts, they die, but good quality devices tend to be ok running at that level.
But it's still safer to start slightly low vs high.
Do NOT go higher than the first notch over 5 volts as the risk of killing stuff increase exponentially with over voltage.
As your battery input current is up to 2.4A then maximize to output current of the E-werks at 1.5A.
That's how I've set up mine.

Luck ........

[iainwarner]

Thanks for your help. Out of curiosity what battery do you charge and how do you have the E-WERK set up?

[Tigerbiten]

I now run 2 E-werks.

The first is about 5 years old and is powered by a 12 volt-20 watt solar panel.
This is used to keep my devices (kindle & AA batteries) charged while on tour. This one I run at just under 5 volts as my cheap cache batteries tend to die if I charge them at just over 5 volts, I think I got 5 for £50 off ebay. My powermoney cache battery is still fine after being charged at just over 5 volts for roughly 5 years.

My second one is only a year old and is powered off my SON hub dynamo. I use it charge a B&M cache battery and then my Garmin sat nav. This one I run at just over 5 volts. I got the B&M cache battery as all the joints bar the Garmin one are waterproof so less risk off something dieing in the rain. I don't need the battery at speeds above about 3.5 mph with the lights off. But I cannot stop the Garmin complaining about lack of power at speeds below this and threatening to turn off after 30 seconds and sub 3.5 mph is easy on a bent trike .......

This now gives me the best both world when charging devices while on long multi-week tours.

YMMV .........

[andrew_s]

As the E-werks doesn't output exactly 5V then you either need to run it slightly under/over that voltage.

The relevant options are 4.9V or 5.6V.
For a power bank I'd use 5.6V, with the current limit set fairly high (and have when I want faster charging).
For something expensive (phone, kindle), charged directly, I'd use 4.9V.

When the e-Werk was introduced, USB charging for things like cameras or lights wasn't as common as it is now.
The logic of 0.7V increments was that you'd use 1.4V for one AA, 2.8V for two, 5.6V for 4, and 4.2V for one LI-ion and 8.4 for two. These are the correct voltages for charging directly with no separate charger.

[ConRAD]

... I want to charge my Rav Power bank Ace series as im riding, Model RP-PB052, Capacity 22000mAh/83.6Wh...

.. i'm a bit afraid that you won't be able to charge your 22000mAh powerbank while cycling; indeed as soon as you'll connect it, the output voltage from e-werk will drop ( whatsoever 4.9 or 5.6V your setting it doesn't matter), voltage will be to low and your rav will enter into an idle status, maybe showing some led lit but not charging at all. However good luck.

[Sweep]

Can you explain why you think it won't charge conrad?
Not a challenge, a genuine question - not my area of expertise at all.

[ConRAD]

- e-werk is not a normal "WALL USB POWER SUPPLY"
- e-werk normally relies on a dynamo that is commonly referred as a 3W/6V AC-Generator (when connected on a 12 Ohm resistor at 15 km/h)
- now to say that setting e-werk I/U dials on 4.9V/1.2A equivalent to an overall 5.9W is simply a non-sense
- what happens? Answer: the powerbank starts to draw as much as possible current, the e-werk output voltage in-turn drops and below a certain voltage the charging process simply stops!!! This conclusion is based on my personal and also fahrradzukunft.de relevant tests.
FYI e-werk maximum power at 20 km/h is roughly 2.75W.

[ConRAD]

I suspect that at the base of a certain undisputed and still lasting success of e-werk there might be a sort of a possible general “misinterpretation” in terms of its actual technical data still presented by the manufacturer under the following terms:

- input voltage 0 to 40 Vac, 0 to 50 Vdc
- output voltage adjustable from 2.8 V to 13.3 V in steps of 0.7 V
- output current adjustable from 0.1 A to 1.5 A in steps of 0.1 A
- input frequency 0 to 100 kHz
- max output power 16 W

PS: in the picture below two of these objects perfectly working that I nevertheless use for testing purposes only. For USB devices manufacturer suggests to use 4.9V/ 0.5A setting but, IMO, either 4.9 or 5.6V seem not to be the right choice, i.e. e-werk has not been designed to play the role as an USB charger!!

[Sweep]

Back to my O level physics Conrad.

So when you refer to its "success" you mean continued success in selling them to the unwary rather than sucess in charging their powerbanks?

Have an uncomfortable feeling that we have been here before, but can I ask what you use for charging stuff on the move?

[Gattonero]

I have had more positive experiences with the USB/Werk, which cannot adjust the output but has an integrated cache battery.

[ConRAD]

... so when you refer to its "success" you mean continued success in selling them ...

Yes, "commercial success", success mainly constructed around a device too often presented as capable to offer up to 16W with any possible I/U dials combination ... deliberately overlooking that power is so far generally coming from a dynamo with its very well known limitations and that voltages different from 5V are reasonably useless in a today USB dominated world.
So at a certain point I put aside my two e-werk and bought a "zzing" that acts as an AC/USB_DC converter and has at the same time a built-in 2600mAh battery. As a separate item I have a 24000 mAh power-bank that can be charged either from a 12V car outlet, or from a 16V laptop power supply, from a 18V photovoltaic panel, from its own wall power supply, etc. etc.
PS: to charge big power-banks through a USB-5V connection I think that they must comply with the new USB_PD-Power Delivery standard that can arrive, if I'm correct, up to 100W ... but that's not the case of the e-werK!!

[Martyn]

Hi ConRAD,
Like you, I think B&M items are over-priced for what they are and I'm trying to design something similar from components and boards available on the net.
Your Zzing AC/USB DC converter with the built-in battery sounds like exactly what I have been looking for but all my searches for it have failed to produce anything. I suspect they may have been taken over or gone out of business. Do have any other details about the company or a model No for the one you have and a vendor that you bought it from, please?

[andrew_s]

look here
Search for "zzing usb charger" (as suggested after getting about as far as "u"), and it's hit 3.
More training of your google-fu required, I think.