I am sure allot of people want USB Chargers in their older cars, trucks, etc that do not have them. I have used a number of cigarette lighter adapters with either 1 or 2 USB ports and they are absolute junk. The most common point of failure is the cigarette lighter adapter and socket in the vehicle. So to get a real 7 port USB hub working in your vehicle it comes down to getting the right amps and voltage more or less. I looked at the D Link 7 port USB 2.0 HUB I have on my computer at home and the power adapter's specs are: Input: 100-120V~0.4A, 50-60Hz LF Output: +5.0V ===== 3A I looked around and some of the new USB chargers that plug into the cigarette lighter with 2 ports say they pull 3.1 amps (One USB port takes 2.1A and the other 1.1A) Apparently Ipads and tablets need 2.1 amps or they will not charge. (I noticed this with some USB ports on my laptop. The Ipad will "conntect" for data, but it will not charge off that USB port on the laptop which is odd. So my guess (I will need help here) is that if I want this 7 Port USB 2.0 HUB hardwired in my truck somewhere I would have: Input: 9v-14v (Typically 12v) Output: I need 2.1amps per USB port to charge what ever is plugged in so (14.7 amps) total and +5volts Also to make this work, I would need to regulate the Input down to 5v some how from 12v. In searching for the answer to all this, I also read that I might need a DC to DC converter? not sure how that works, it seems redundant.