Blog header

Using Your Dynamo Hub for Device Charging

this entry was updated February 1, 2018 by Luke

Dynamo Light Display Bike

Our Dynamo Demo Bike at Perennial Cycle

It's no secret that we're big fans of using Dynamo hubs to power lights. The idea of being my very own utility power station makes me smile almost as much as knowing that my lights will ALWAYS be ready for me when I'm headed out on the road. We also have a variety of products that use the same Dynamo hub energy to charge a mix of USB devices. Your dynamo hub can charge lights, an external battery, a GPS unit or your smartphone during rides. Touring cyclists can charge USB devices on the road. The key piece to make this happen is a  front wheel with a dynamo hub.

Busch & Mueller Luxos U

Busch & Müller Luxos U Dynamo Headlight/USB charger

Dynamo powered USB charging options:
IQ2 LUXOS U HEADLIGHT: This is what we think the future of dynamo lights will be. Weird to say, being that it is a product available today, but we expect all the high quality dynamo lights to eventually have a USB charging port built-in (like the Luxos U has). If you're looking for a high power dynamo light AND the ability to charge USB devices, this unit is what you're after. Up to 90 lux of light (floodlight) with a lithium battery cache that charges while riding and powers the floodlight, standlight and USB port. The Luxos U has overvoltage protection which is a great feature being that you'll have your expensive devices plugged into it.

Busch & Mueller USB WERK

Busch & Müller’s USB-Werk

USB-WERK: Busch & Müller's USB-Werk uses dynamo power to charge USB devices. Like the Luxos U, the USB-Werk has a small buffer battery cache to safely charge your iPhone, Android phone, MP3 player, GPS or other USB devices at any speed. The USB-Werk can be used as a stand alone item that is connected to your dynamo hub, or (more commonly) it can be wired along with your dynamo light.

Cinq5 The Plug III

The Plug III, Dynamo USB Power Suppy

Cinq5 Plug III: The Plug III is a USB charger and a 1-1/8" topcap for your threadless stem. It would be difficult to integrate a charger any more eloquently. It is a bit bulkier than a typical top cap, but there's a USB port! The PAT II technology used in converting the dynamo energy into a current that your device can pull from does an awesome job of allowing your device to charge even at slow speeds. I have used this device a lot (most often with an iPhone SE) and have found it to be very reliable. It successfuly charges my phone even when I'm running map aps and have bluetooth running. The Plug III is a lovely and very reliable charger. I'd recommend it whatever your needs are.

Cinq5 Smart Battery Pack II

Cinq5 Smart Battery Pack II

Cing5 Smart Battery Pack II: This is not a charger, but it's worth adding to the page. We have found that some phones or devices struggle to get a steady flow of power to them for charging. Sometimes a device seems to lock onto a stream of power before the flow of power is at it's peak. In this situation the hub is pushing a higher amperage of power than the phone is letting in. I don't have that problem, but a buddy of mine with a superior charging system* is challenged to charge his phone on the road. To get a steady charge he needs to get the bike up to speed, let the charger build up a cache of power and then plug in the phone so that it locks onto a higher amperage. With the Smart Battery Pack II in the middle, this problem is solved. You can simply charge the battery and later use the charged battery to charge the device, or you can use the battery as a buffer by having it plugged into your dynamo charger and your USB device at the same time. Another reason you might need the Smart Pack is that your device requires higher than .5 amps to charge it. No dynamo device is going to push more than .5 amps, so potentially you need to charge the battery and later charge the device with the battery. An iPad would be an example of something needing more than .5 amps.

Biologic Reecharge Dynamo USB Charger


Biologic Reecharge Dynamo USB Charger

REECHARGE POWER PACKThe Biologic ReeCharge Power Pack is another way to charge your smartphone, cell phone, GPS, iPod or other USB rechargeable device. The Lithium battery on the ReeCharge Power Pack is a bigger battery that you can plug your USB chord into and charge while riding, or simply charge the Reecharge Power Pack's battery on the road and then use as backup battery power at the campsite. This system also provides a steady current to your device no matter what speed you are riding at. Also of note is that the ReeCharge Power Pack's battery can be charged by a USB from a computer or a USB wall plug power source (not included).

•       •       •       •       •       •       •       •       •       •        •       •

If you are starting from nothing, we'd be hard pressed to recommend anything other than the Luxos U as the light is very high quality (and high powered) and the USB plug is wired to be on your handlebars along with the light's control button. If you already have a dynamo light, or want something different from the Luxos U (the Luxos U seemed a bit large for my Brompton folding bike), then the Busch & Müller USB-Werk,  The Plug III or the ReeCharge Power Pack are excellent options for keeping your smartphone or other USB device powered up. We are the midwest's largest dynamo specialist with a large assortment of dynamo hubs, wheels, lights and accessories in stock. We also understand the importance of getting these systems setup properly and we have the expertise to do that very well. Give us a call or stop in if you have questions about getting a dynamo setup for your commuter or to get setup for an around the world tour.
Here's a link to view our Dynamo related items at the shop: Dynamo Category

Dynamo Lighting @

NOTES: Dynamo hubs have limited power output and thus cannot charge all USB rechargeable units. If your device needs 1 amp or more, then you will need to use your dynamo power to charge the Smart Power Packk II or the ReeCharge Power Pack's battery which in turn can be used to power your iPad. iPads are known to require more than 1 amp to charge and thus cannot be charged off of dynamo power. The output of these dynamo USB ports is .5amps which is actually the same as a USB port on a PC. The reality is that if your screen is off, charging will occur, but very, very slowly so in reality it's best not to consider it a working option.

MORE NOTES: Good quality dynamo hubs have an output of 6 volts/3 watts of power. These are the huge majority of dynamo hubs in use, BUT there are some 1.5 or 2.4 watt hubs that are made. These are quite low quality and will not work with any of the USB charging units. No worries if you have purchased your dynamo hub from a reputable bike shop, but if you're an Alibaba or eBay troller you'll need to be aware...

*The reason I believe my dynamo sytem is inferior to my friend's is that I use a hub designed to small wheels (SONdelux), though my bike has 700c wheels. These hubs have a little less rolling resitance, but in theory you would need to be going faster to get full power out of them. He uses the SON 28, which is designed for the 700c wheel, which is what his bike has.