I'm trying to solve a charging issue for tablets in my cars. We need to leave the tablets in the cars all the time (this is for work) and the temperature in the cars in Phoenix reaches 120 easy. The tablets are fine, but the batteries hate it. We've figured out also that the lighter-chargers don't put out enough current to actually run the tablet, so the batteries run down, even when plugged in and charging. We'd like to hard-wire the tablets, primarily to get enough juice to keep the tablets charged. Ideally I'd find tablets without batteries and just run them always plugged in, but the reason tablets are affordable is that they're not custom. The hard-wire harnesses I see coming from China don't seem to have any images or notes about amperages on them, nor any notes regarding this issue. Any advice?