Bicycle dynamos are nothing new, but charge-while-you-ride technology has improved by leaps and bounds in the last few years. Affordable powerpacks in the form of portable batteries make it possible to not only charge devices, but store energy for when you really need it.
These days you can charge just about any device that uses USB power using your own physical exertion, including smartphones, tablets and rechargeable lights. Here are the best power solutions for cyclists who need to charge on the go.
Sometimes when you’re designing the next generation of technology, you need to look back at past inventions and improve on them. Dynamo efficiency is reaching new heights, but the premise of harnessing the rotational energy of the wheels is nothing new.
Siva Atom ($129)
The Siva atom is a charger with integrated dynamo that attaches to the rear of your bicycle and provides a 5V charge capable of charging iPhones and most Android and other low-power devices. It was one of the first next generation devices to provide an all-in-one solution comprising of a dynamo, power converter, and detachable rechargeable battery.
At present, the device will only fit to the rear of a bicycle and is incompatible with disc and coaster brakes. It works with fenders, racks, and panniers and is suitable for use on most bicycle frames. According to Siva, added resistance is “very small … proportional to how large your charging load is,” so you won’t be exerting yourself unnecessarily if you don’t need to.
The detachable 1650 mAh battery pack can be charged before you head out for a ride, which means you’ll only have to keep it topped-up as you use it. It’s rated to a waterproof rating of IP4, which will guard against “splashing of water” — it should be fine provided you don’t fully submerge it.
Just like the Siva Atom, Tigra Sport’s BikeCharge Dynamo is a highly efficient generator that uses the rotational movement of your wheels to generate a constant 5V DC charge your gadgets can use. It too is an all-in-one solution, encompassing a dynamo, converter, and 1,000mAh battery internal battery that cannot be detached or charged through any means other than pedalling.
The BikeCharge is designed to attach to the left side of the front-wheel, which means it’s fully compatible with bikes that use disc brakes (and naturally, rear coaster brakes) as these are frequently mounted on the left-side of most bikes. According to the manufacturer description, it will fit 95% of bikes worldwide, with only an 8mm clearance required between the fork and the spoke.
Despite not having that handy detachable battery, the BikeCharge does come with front and rear facing white and red LEDs on the unit itself, which can be turned on and off using the included remote control. And of course, you’ll never have to replace the battery in those lights.
Dynamo Hub & USB Charger
Buying a dedicated dynamo hub is probably the most efficient way of generating electricity on the go, but there are few things to remember. Your dynamo will output an AC current, which fluctuates massively in terms of voltage and is utterly useless to your DC-guzzling gadgets. If you buy a dynamo hub, you’ll need to convert the AC current to DC and add a USB port to make any use of it.
In addition to being hugely efficient, dynamo hubs are also incredibly lightweight and often don’t cost that much more than a standard quality wheel hub. While they’re generally a more expensive solution to the all-in-one products provided by Siva and Tigra Sport, you don’t have to buy it all at once.
You can buy a dynamo hub first, then buy your power converter and (if desired) a battery pack as you need it. Here are some examples of some dynamo hubs you could use:
- BioLogic Joule 3 — 73% efficiency (manufacturer rating). $129-$149
- Shimano Nexus DH-3N80 — 67% efficiency at 20 km/h, front wheel dynamo. $75-$100
- SON Delux — 65% efficiency at 15 km/h (manufacturer rating). €279
- SP PV-8 — 72% efficiency (manufacturer rating), rim brakes only. $125
Then you’ll need to attach your dynamo to a USB charger that controls the voltage:
- LightCharge II — works with SON connectors, overload protection. $79
- BioLogic ReeCharge Power Pack — 1,600mAh battery, weatherproof. $99
- Sinewave Revolution — completely waterproof, overload protection, gold-plated USB connector that won’t rust. $120
- Supernova The Plug III — stylish and compact, if a little pricey. $190
You can mix and match hubs and chargers based on your needs and available budget.
If you’re thrifty and love the challenge of building something, Make’s DIY pedal power charger uses a traditional run-on-tire dynamo to produce a smooth 5V DC current your devices can use. You’ll need to know how to solder and have access to voltage regulators and rectifiers (by means of a local electronics shop), and you’ll probably learn a thing or two while putting it together.
The finished build doesn’t include a battery, but you could just as easily add one by adding a portable USB charger at the end — they charge using USB power, and often can be used to “pass through” USB power to your devices while being charged. It’s not an elegant, paid solution, but it’s fun, effective and much cheaper.
You might also want to check out the USB Bike Generator on Instructables which is similar in design.
Dynamos are great for those who commute and ride in the dark, but some may prefer a solar solution instead. Just like dynamos, photovoltaic panels have improved massively in terms of efficiency since they first hit the market. Many have also become a lot smaller — small enough for use by cyclists.
PowerBee’s solar chargers are both highly efficient and compact enough to mount on a bike. The PowerBee Executive retails for around £35 and comes with a 3,500mAh lithium polymer battery. It’s perfect for mounting on a bike, charges in 12-36 hours (depending on conditions and where you are) and contains enough juice to charge most mobile phones at least once, maybe twice.
Voltaic creates a whole range of solar charging panels aimed at cyclists, like the wearable Fuse — which comes in 4W, 6W and 10W varying sizes and can be mounted on the back of a rucksack. Voltaic’s most portable solutions come with a 4,000mAh battery, though there are some serious chargers that hold up to 20,000 mAh for use with larger panels.
PowerFilm creates solar panelling that folds up and fits in your pocket, allowing you to only use it when you need it and keep it safely tucked away when you don’t. Using the kit it’s possible to charge two AA batteries (included), which you then use to charge your USB devices.
According to the manufacturer, the batteries charge in just four hours of full sun, though this will depend entirely on the total capacity of the batteries you choose.
Batteries: Your Other Option
There are a huge number of portable USB chargers out there now, from high quality products from the likes of Mophie to the super cheap Amazon Basics range. Amazon even has a 10,000mAh capacity portable power bank for just short of $30 — enough to charge an iPhone 6 five times! The downside? You’ll need to ensure they’re charged up before you leave the house (or add a dynamo and USB charger into the mix at a later date).
For more bicycle products, check out the best bike trackers for catching thieves.
Image Credits: guy is riding a bike Via Shutterstock