Battery Box for Bicycle to support PNA (Navi), Mobile, ... (devices that can get power via USB)

thingiverse

I have a Falk iBEX30 cross PNA navigation system mounted on my bicycle with a battery that lasts about 4 hours. This duration is too short for longer tours, but it can be powered externally via mini USB for example by a power bank or by the generator for the bike's headlights. The only problem with it is that it goes into USB device mode if a common USB cable is used and shows just the USB symbol on the display, which doesn't help me much if I want to know my route. One solution could be to modify the USB cable so that it only has the wires for ground and 5 Volts, not the lines for the signals. That's what I did, but I went one step ahead by putting a LiPO battery into a little box with some electronics and mounting it to my bike. This battery is loaded by the generator and provides external power for my PNA for several more hours. A usual USB power supply could also be used for loading the battery before you start. The box and the clamp are separate parts screwed together, making it a bit modular, and only the clamp has to be modified to mount it somewhere else. The inner diameter of the clamp is 45 mm, and the distance between the two holes for mounting the box is 18 mm. The published version is my final V1, which had already some iterations. It does what I expected, but there could be some enhancements: 1. The opening for the switch could be in the design. I made it by filing. I had to add the switch because there is a LED on the second circuit that consumes some power. 2. Provisions in the box to mount the electronic parts could be added. I did it with hot glue. 3. Enhancements to see the status LEDs on the small PCBs from outside the box could be made. 4. An additional USB connector A-type female to connect different USB cables could be included. I'm not sure if I will do these modifications, but if I do, this entry will be updated. Please also see "Misc Notes" later in this entry.