A reader writes:
[What is] the future of cycle electrics? Dynamos vs power banks. Lights are becoming much more efficient, but there’s more and more requirements for charging eg: mobile phones and navigation. Any thoughts?
Thanks for the question! I’ve had a fair few questions about tech and cycle touring, specifically about getting the best out of smartphones on bike trips – but none about what the future might hold in terms of electronics and their ever-increasing demands for power. It’s an interesting one!
Well – I don’t know exactly what the future of bicycle electronics holds, of course, any more than the future of mobile device technology in general.
But I am pretty sure that, as it is now, it will be a case of supply and demand helping each other move forward. As devices become more power-hungry, the power supply industry will develop more efficient, clever, and expensive ways to feed them. There’s a lot of money to be made here (and, incidentally, in delaying the rollout of advanced technology in order to capitalise in the shorter term on existing inefficiencies).
Another way to put this is that ten years ago I could find power banks and dynamo charging solutions that between them would keep my current phone charged on a bike tour, and exactly the same is true today – just with newer products.
So the same will probably be true a decade from now as well. (It’s interesting to look back at this piece I wrote about the technology I was using at the time.)
Since you mentioned dynamo hubs (aka: generator hubs), it seems important to note one constant in all of this, which is the range of useful electric currents it’s possible to generate from the rotation of a bicycle wheel.
We aren’t likely to start cycling faster in order to charge more devices, nor fit smaller wheels to our bikes to increase the rate of rotation of our dynamo hubs (at least, I’m not, even if it is a marginal argument in favour of 26-inch wheels for touring bikes!). Even the best dynamo hub and voltage transformer combinations can still only supply a single USB charging port at typical touring speeds, and then only at currents on the lower end of the current spectrum. Put another way, the laws of physics mean rapid charging off a dynamo hub will never be feasible.
What that means is that it isn’t really a question of dynamos vs power banks, as you put it.
It’s more whether a dynamo hub is a useful supplement to the inevitable necessity of a power bank and/or wall charger if you want to keep multiple devices powered on a bike tour.
Whether or not a dynamo hub is useful is mostly about pace and terrain. Right now, you’ll get a useful output from a dynamo hub and transformer at a constant speed of around 12–13kmph or more over long periods of time, but the same setup will be all but useless when crossing a steep mountain range, as you’ll be going too slow on the uphills and too fast on the downhills to produce a useful current.
Back to the original question, if you really twisted my arm and forced me to guess what the future holds, I’d imagine that the raw power demands of phones will continue to increase in the short term; phone batteries, power banks, and distributed charging infrastructure will evolve in line with that; dynamo chargers won’t be able to keep up with these power demans; and by the time battery efficiency comes back into line, the fundamentally inefficient device that is the handheld smartphone will have been replaced by devices that interface more directly with users anyway.
AirPods and smartwatches etc are the beginning of this trend. It’s already possible to pocket your phone and have it give you audio navigational directions via a wireless headset. As soon as augmented reality tech is routinely able to project virtual maps, signposts and directional prompts onto the lenses of our cycling sunglasses (or something comparable), the phone itself will become all but redundant for the purposes of navigation on a bike tour.
It’s also possible that more riders will realise that smartphones are actually quite shit at almost everything.
As navigation devices, they’re overly power-hungry with poor outdoor screen visibility and are inherently fragile. As cameras, they don’t come close to a dedicated digital camera with a real piece of glass in front of the shutter. As entertainment devices, they’re too small to watch videos on without squinting and too stridently loud to use in public without blocking out everything else via headphones. As communication devices, the apps involved are infested with dopamine-triggering tricks that cause you to spend far more time pointlessly scrolling and chattering than you ever intended to.
(And don’t get me started on social media apps and the borderline-narcissistic tendencies they produce in users who believe that turning every aspect of their bike trip into “content” is benefitting anyone other than those who leverage that content to sell ineffective and intrusive ad placements. Rant over.)
Trends swinging like a pendulum as they do, perhaps we’ll see more people returning to DLSRs and compact mirrorless cameras for the joy of photography, fitting dedicated cycling GPS receivers that last for days and are visible in bright sunlight (or using paper maps and road signs!), and keeping their phones packed away and using them mostly to keep their friends and family updated. Who knows?
For what it’s worth: having experimented with the current state of device charging technology in Australia last year, my upgraded touring bike setup includes a Shimano dynamo hub and VeloCharger USB transformer, which I mostly use to trickle-charge a 10,000mAh Anker power bank.
As well as that, I keep a rapid-charging USB wall charger close at hand, which I use in cafes, campsites and filling station toilets to keep my smartphone topped up (even a 15 minute stop is worth it). Then I fall back on the power bank if mains power isn’t available.
I use the phone as a GPS to avoid multiple redundant devices, and employ various battery-saving techniques to prolong its charge. And if I’m on a long, flat stretch and I know I’ll be able to keep up a decent pace for an hour or more, I’ll connect the phone directly to the dynamo/transformer to give it a boost.
That’s all I can think right now of for regarding the future of cycling electrics. Hope it helps, and/or is at least an interesting enough ramble to warrant publishing!
This is part of my “No Stupid Questions” series, in which readers write in with questions about cycle touring or bikepacking and I attempt to answer them. Check out more recent posts in the series or ask one of your own.
Something to add?