dynamo & smartphones

Using dynamo charging units to keep your devices charged up on an extended race, event or tour gets a bit tricky as there are many variables at play.
The simplest way to be sure you will be successful is to use your dynamo generated energy to power a power bank (battery). We had 2 customers that did the 2019 Paris-Brest Paris (1200K!) and both of them used the Power Pack II to charge their GPS & phones with success.
One of the tricky parts of using dynamo energy with devices is the constant fluctuation in power output. Many electronic devices lock onto a small trickle of power and do not take in more power when it becomes available. This leads to NOT charging the device. Some devices re-assess and take in higher levels of power when it becomes available (my iPhones have always seemed ok at this), but not all. So the only sure bet is to use a power bank that is designed to adjust intake as it is available. Not all (in fact few) power banks can handle this power management.
The Cinq5 Power Pack II as well as Goalzero Power Banks have been specifically designed not only to accept an ever-changing flow of power, but also are capable of acting as a pass-through. This means that the power bank can be used to charge a device at the same time that it is being charged.

We do a lot of dynamo lighting setups at Perennial Cycle. We have customers using dynamo power to light up their way home from work, keep them well light and fully charged on massive road rides, heading into the woods bike camping or cross country touring.
Lights for dynamo are pretty straight-forward and info can be found HERE.

Personally I've used the Plug III as well as the Igaro D2 Pro R2 to charge a few different iPhones over the years with great success, but how successful you are at charging a device with dynamo charger will depend on the amount of daylight you have (dynamo chargers do not charge AND run your lights), the device you are charging and the speed you ride at.
If you have time, it is best to do a fair bit of testing.

This post was updated November 8, 2018 by Luke

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. In order to do this you need a  front wheel with a dynamo hub and a charging device.

Dynamo powered USB charging options:

IQ2 LUXOS U HEADLIGHT: This is a very technically advanced product in that it's a very powerful light that comes out of the box with a USB port for charging devices. 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 uses the cache battery for overvoltage protection. A great feature being that you'll have expensive devices plugged into it.

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 cache battery 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 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.

Sinewave Revolution: The Revolution is Sinewave's USB charging unit. Sinewave manages the power flow to your device without utilizing a cache battery. It's the lightest option that we've seen and without a battery in the mix, it could potentially run indefinitely.

Cing5 Smart Battery Pack II: lThis 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 friend of mine is sometimes 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.

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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 Sinewave Revolution; 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

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 Pack II 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 system 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 resistance, 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.