Dynamo light and charger insight

[doctor-bond]

So, I’m finally putting together a Dynamo wheelset (will prolly go Shutter hub, but may dig deeper for a Son). I’m not fussed for a rear light connection (nasty wire run and modern battery Led ones are v. Good). But I do want to be able to charge a phone on the hoof as well as see in the dark.

Before I delve into the bowels of SJS, I figured the RB massive would be able to shed some light on the best way to do this: eg do I need a power splitter/transformer; or just use the connector for the rear; or get a front light with a daisy chain usb output?

Here’s a random hub shot to brighten up this post.

 

[greencat]

My understanding is that dynamos can be quite spikey and noisy in terms of power output. You'll definitely want something between it and any sensitive phone electronics even if it puts out the right volts/amps. Maybe a charge controller of some kind?

 

[doctor-bond]

Ah, interesting, thanks: I’ve got some learning to do on electrics. (Or is it electronics?).

 

[bikeworkshop]

Seems pretty unanimous with the lighting/ charging setups we've seen in the shop - they cost a lot of money and either don't work very well or not at all.

Waterproofing the socket is an issue, and the dynamo doesn't really produce power right to run both systems.

It would be cheaper to carry a backup battery, stop for a coffee and charge it while you're there.

It does tend to be one of those
bike-evangelist features though

 

[doctor-bond]

Hmmm, I have picked up on the evangelists, yet I’m also drawn to the simple fact of having light when you want it without worrying about batteries (I've got a pretty decent rechargeable set up, but even that never seems to be fully there when you need it (eg - impromptu night ride when you haven’t had the forethought to charge it)).

Could be that getting the lighting right first is the key then seeing about phone charging.

 

[legrandefromage]

for anyone reading and thinking of using older dynamos - they were alternating current so some sort of rectifier was needed for a DC output to charge something

modern hubs should have that all built in

 

[bikeworkshop]

It's a little unwise to connect a smart phone directly to a dynamo.
Usually you'd charge a battery pack.

But if you've got a battery pack, just how far are you riding from electricity?
You're probably going to carry a plug in charger after all.

We did have a customer who was planning on crossing Mongolia, disappointed with his fancy phone charging setup.

He seemed shocked when we said people used to do that
without any phone at all!
Let alone Smart.

Making one thing do 2 very different jobs involves compromise.

 

[doctor-bond]

Making one thing do 2 very different jobs involves compromise.

And a donkey load of moolah: have just been checking out the hardware needed for constant, spike free charging - whether via a smart light or a standalone, er … pack-dongle.

(I’m reminded that I cycled round South Asia without a phone, lights, insurance or helmet - but have been thinking I might need a satellite phone for some off roading in Scotland ….)

 

[doctor-bond]

A Light

 

[bikeworkshop]

and it manages to look like a £10 amazon job