The HTC One has a standard micro USB connector, so one would assume that when charging you can use any micro USB connector lying around both at home and in the car. Well you can but be warned.
In the car and at home you need to make sure that when using a third party cable and plug that you are charging AC power mode and not USB. Nothing wrong with USB mode except it’s slow and in the car might not charge the phone quick enough as you use the GPS, Bluetooth and more. If you use HTC’s own car and supplied charger you will see the below screen shot. Go to settings, power and top left it says AC charging.
Now if for example you used an iPad wall part with a USB cable the top left wording would change to USB charging which takes a lot longer. In the car I originally tried a Kensington car charger block with a BlackBerry micro USB cable. This only gave USB power and consequently when I had GPS and Bluetooth running the phone battery died by 2% every hour. Swap over to the official HTC car charger, AC power mode is triggered and the phone chargers ahead despite using it heavily.