I'm not an expert on digital dash setups, but I am an IT major in college.... Most digital logic controllers run on 5v circuits, even though a car's elecrical system is 12v, lots of the sensors and other electronics in the system operate by a 5v signal too. The computer systems in the car contain voltage regulators that generate the 5v power source for the low current digital stuff. Most comercially used 5V regulators only require a minimum input of 7v, so if you've got a decent amount of light coming from the dome lights and such, you probably have more than enough voltage for the digital stuff to work decent. I guess you'll probably have a definate answer by the end of the day anyway when the charger decides it's done, but boy suspense is a big B word isn't it?