Here's my Mobley. Paying $20/month with no contact for unlimited (22GB LTE, then throttled) in the car connected device plan. Paid $99 direct from AT&T online and had it literally next day with free shipping.
There was no way I was paying $25-$30 bucks for an AC adapter. Nope.
I'm tech savvy and decided to mod my own. I didn't want to make any mods that would make it unable to plug into the OBDII port, so I decided to simply open the unit up and tap into the power lines (pins 4 and 16) and solder on some leads and use a screw terminal barrel connector. This allows me to power the Mobe in three ways: 1.) Standard 12V AC wall adapter. Mine is 2.5A, but I would recommend at at least 1.5A. 2.) Battery pack. I can use a brick of 8 AA batteries or any sort of battery pack with a 5.5mm barrel. 3.) Vehicle 12V cigarette charger with a 5.5mm tip.
The newest firmware has a no timeout option, so I've been using it at home and work as well as in the car. Speeds aren't what I was expecting (likely due to no carrier aggregation), but still a hell of a deal for $20/month (and probably less than that since I will be using a discount code).
