Dynamo light and charger insight

I've run them for more than a decade. I need to do an update on my setup in another thread.
Personally when touring I always take lights - I've had several occasions when transport delays and other problems have led me to be riding in the dark unplanned. Generally this is a dynamo.

The problem with charging phones directly (main tourer has an Axa Luxx lamp with a USB charge socket on the side) is that the start-stop nature of charging (e.g. junctions, slowing etc) causes the phone to helpfully light up and say it's charging. This often consumes more power than the charge rate, depending on how daft the phone design.

So, it's best to charge a cache battery pack, then use it to recharge the phone in one big go. It also allows other things like GPS etc to be charged. It's up to you whether you then go the whole hog and use USB lights charging off the pack too.

Personally, for lights I am 100% satisfied by the B&M IQ+ on my road bike, paired with an SP dyno. I rode the Dunwich Dynamo in the summer and having zero lighting range anxiety was reassuring. The light has a good low wide beam spread.

For USB charging you can buy some like the https://www.sjscycles.co.uk/dynamos/klite-micro-usb-charger-box-type/ which aren't that cheap, or use a home-made circuit (plenty on the internet). Typically they use the 7805 regulator IC which is not great on efficiency but simple and does the job. There are also eBay converter modules for around £10 like https://www.ebay.co.uk/itm/12671362...044&customid=a5f753adf3d317db3a583483e76d9e49
I will get round to trying them soon.

Here is an old but pretty good article. https://www.cyclingabout.com/best-dynamo-usb-chargers-bicycle-touring-bikepacking/

There is also a lot on the Cycling UK forum.
 
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Thanks @hamster, that’s useful real world insight. Other commentators I’ve been coming across also highlight the merits of the charge a powerbank approach.

I’ve been looking at drag data (🤦‍♂️) but it’s all relatives: how noticeable is Dynamo drag in day today riding?
 
Thanks @hamster, that’s useful real world insight. Other commentators I’ve been coming across also highlight the merits of the charge a powerbank approach.

I’ve been looking at drag data (🤦‍♂️) but it’s all relatives: how noticeable is Dynamo drag in day today riding?
Frankly I never noticed a difference. It’s less than the difference between a clean or dirty chain, or tyre pressure.
 

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