Help connecting ebike charger to USB

[forwhere]

I want to connect a USB cord to the battery of my ebike charger. The connector of the ebike in the pictures looks like a male coaxial power connector, but I'm not too sure as it doesn't have the grooves of a coaxial. I'm new to this and have searched all over looking for a connector to connect to USB.

The dimensions are: head (3mm), inner width (8mm).

Would appreciate any pointers in the right direction!
Kay

 

[Harald Kapp]

What voltage does the ebike charger output? I very much doubt it is 5V. An adapter to USB is useless in that case.

 

[forwhere]

Hi Harald - thanks for your reply. It's a 42V output for the charger. How would you set up an ebike battery to charge a phone then? I go on long rides and I'm trying to see whether I can do that. Thanks

 

[Harald Kapp]

You will need a voltage regulator that creates 5V from 42V. As this is a rather high voltage difference, a switch-mode regulator is the best option to save energy.
You can buy off-the-shelf ebike USB chargers (here's an example) that then should come with a fitting socket.

 

[forwhere]

Awesome. Thanks.

 

[forwhere]

Harald - can we chat on Skype directly? I need more help with this project.