Monday, April 27, 2020


Is that a disco in your bumbag, or are you pleased to see me !

What do yo do when you have weapons grade tail-lights and it's a waste to have them mounted on just the one dynamo bike? Mount them on your bum bag and you are good to go!

A truncated handlebar, with a Qube atop.
I just got 108 hours continuous flashing out of one 18650 rechargeable battery encased in this 2 cell power-bank case. Probably not what the inventor of the Qube, Kerry Staite had in mind when designing ultra efficient tail-lights for dynamo rigs, but I never leave the house without my bumbag anyway, so it makes sense to me. With quite a few bikes to choose from, it's now no longer an issue, as far as rear lighting goes.

I should state that this is an unsanctioned hack, as power-banks all work differently, and Kerry's Qube lights have such a tiny drain that most "proper" power banks don't notice when a Qube is even connected after a while, and they automatically switch off.

Kerry uses some clever super-capacitors in the flashers than mean that they will keep flashing for 3 minutes after being disconnected from their power-source, obviously a very cool set-up for a dynamo scenario.

Anyway, it worked for me with this particular combination of 18650 cells and the power-bank case that I used, so if you want to give it a crack, details are below.

If you think this is overkill then you likely don't commute (like I do) on the highest trafficked heavy vehicle route in New Zealand. Despite lobbying since 1904, there has never been a cycle lane for cyclists riding from Wellington City to the Hutt Valley.

Bits and pieces
1 bumbag with loopy bits on the back. Purchased in Japan.
An old Salsa carbon handlebar.
4 handlebar plugs.
4 zip-ties.

This is my favourite 18650 battery, but you can harvest them any older dead lap-tops, early model Nissan Leafs or Teslas you find at the recycling centre.

Power Bank case from Aliexpress. These cost a few bucks, $3 US. They probably work because they are unsophisticated and don't try to be too clever. These cases are also chargers, so you could put the batteries in and use it to charge them if you wanted. I don't, I have a separate charger that is faster, and that I would trust more, but even then I would not leave the house while leaving any batteries on charge.

K-lite Qube lights.

Recycled 18650 batteries from a dead lap-top battery pack.

No comments: