Was going on a 30 day motorcycle trip with my sons and needed to charge our gadgets so I made this connector
After doing a search here I found this https://www.instructables.com/id/Adding-a-Car-Charger-to-a-Motorcycle/
But mine was a bit different in make up and use. So I posted mine. I have a battery tender connected to my bikes. My usb/charger connects to the same wire used for charging the battery. If you don't have one look at myargonauts post linked above to set it up. I also found it makes a pretty good fake alarm system
Step 1: Parts
12v socket found on ebay with search of (Waterproof 12v Accessory Power Socket) 4 bucks each
pvc cap 3/4 inch from home depot
sae 12v 2 pin connector amazon has them with connectors at each end of a 12" piece so cut them in half to make 2
Mini Bullet Dual USB 2-Port Car Charger Adaptor 4 bucks each shipped I think its important to get the ones that light up
Step 2: Put Them Together
Drill a hole in the pvc cap and tie a knot in the wire for stress relief or just use some hot glue.
Connect to your power socket (I attached female blade connectors that fit the power socket) Make sure you have pos and neg wired right
Glue the socket into the pvc cap and your done
Step 3: Using Your New Power
As stated above I have a battery tender connected to my bikes. My usb/charger connects to the same wire used for charging the battery. Now I just plug the unit in and I am ready to charge. I use mine in my saddlebag. I can disconnect it or ride with it attached and charging. I also let my phone charge over night without worrying about running the battery down. The other use I stated was the fake alarm look. I left these between the saddlebag and fender at night when we stayed at hotels after I saw a fellows motorcycle alarm had an led light visible. His connected to his phone in his room to go off when disturbed. My usb adapters where pretty bright and I think would be a deterrent. I am going to run another one to my handlebars to run a gps in the future. IN the link at the top myargonauts ran his to the tank bag. I also bought an (USB Mobile Octopus – 10-in-1 USB charging cable) instead of 3 or 4 charging cables.