As you know the Z3C is water resistant and the opening and closing of the USB flap has be worried about the long term water resistance of the device because that flap looks very fragile and prone to bending.
Because of that, as soon as I got the device, I purchased two magnetic chargers on Amazon. One is a little dock that I leave in the table next to my bed. Thats where I charge it during sleep time. The other one is a little adapter that attaches to the magnetic port and allows me to plug a micro usb charger.
The magnetic charging adapter: http://www.amazon.com/gp/product/B00Q3GK3YI?psc=1&redirect=true&ref_=od_aui_detailpages00
Both devices are working really well for me and I thought you all might want one or the other too.