mastakebob

Forgive the newbie question, I'm pretty new to the whole bike scene. I've searched for an answer, but have not been able to find the right combination of search terms (and I just don't have the foundational knowledge required to determine what situations I'm finding are directly analogous to my situation).

What do I need to do/buy to charge a USB device off of a Shimano Dynamo Hub and a B&M Lumotec Topal Senso headlight?

My setup:
Shimano HD-3N30 dynamo hub
B&M Lumotec Topal Senso headlight
B&M Toplight Flat Plus rear light
The hub is connected to the Topal. The Topal has 2 auxiliary (i guess thats the proper term?) power leads. The Toplight Flat Plus rear light is connected to one of these auxiliary power leads. The other auxiliary lead on the Topal is available.

I would like to use the Topal's 2nd auxiliary power lead to charge a USB device. How can I do this?

I've searched for such an answer but have only found commercial devices that plug directly into your dynamo hub (or require you to splice in to the existing hub->headlight wires which I'd rather not do). I have been unable to find a USB charging device that explicitly calls out its ability to plug into a headlight auxiliary power output.

Thanks in advance!

Juha

First off, I'm not sure the 2nd "auxiliary lead" actually puts out any current. Are you sure it's not a ground/earth wire? B&M products are built to the German specs for dynohub/lights, and when you use both front light and rear light, there's no extra power output left from the dynohub. I wonder why they'd put an extra wire there.

zebede

Here are some products. I use the former with wires in parallel with light.
If light is on, USB does not get as much juice. I do not know your extra leads from your light but I would guess they are for a rear light. In other words any device attached would share power.


https://www.thinkbiologic.com/product...icro-usb-cable
https://www.peterwhitecycles.com/ewerk.asp
https://www.amazon.com/gp/product/B00...A19K2B0ZZ0HPUD

lhendrick

I think there is a B&M light that has USB output capability. Don't know about the Topal. I am trying to find where I saw that, probably Peter White site.

** EDIT ** It's the Luxos U model with the USB output: https://www.peterwhitecycles.com/b&m-hl.asp

BTW, and to the OP's questions, I am able to run B&M head and tail lights off my Dynamo hub, AND charge my Biologic Reecharge battery pack at the same time. The wire pairs from the headlight and the Biologic charging device ($100) are simply twisted together before plugging into the dynamo.

unterhausen

I would probably split the wire to the headlight instead of going with the taillight outputs on the headlights. That's always an option if the taillight outputs are tried and fail to work

I tried to order a Luxos U, but everyone else wants one too

mastakebob

Thanks everyone. It appears that I cannot charge USB devices off of the Topal headlight aux outputs. If I really want USB charging, I'll have to run a separate circuit in parallel off of the hub. Or buy a Luxos U (or similar) headlight that has a power output specifically designed for USB. Good to know I can stop that line of inquiry.

julcsf

Since you need a new system, there is the USB2BYK: Website in French
https://eurecart.free.fr/
and to order:

I just ordered one and will get it soon but it has very good reviews on french forums.
I bought additionally the battery (AAA) charger which regulates the current, allows to use the light even when we stop and allows to charge the battery for my headlight.

For a total of 45 euros (<$60) I'll get the device shiped to the us.
That may be worth using google translate !