USB power / DeWalt radio modification

[FwoGiZ]

Hey guys!
First time here so hopefully I am in the right section!
I bought this radio/sDeWalt DCR015 for camping mostly and in the backyard. So basically it can run off DeWalt batteries or plugged in the wall.
When plugged in the wall, it will recharge your DeWalt batteries and also have 120v outlets along with a USB outlet.
But when on battery, the USB and the 120v outlets get disabled
I want to make it that at least the USB stays enabled. I do not have the schematics... Where do I start?
I will upload pictures of it opened later.

Thanks

 

[FwoGiZ]

In this first image, the bottom left PCB is the usb. The one above is the aux jack but as you can see, the USB is connected to it. Then I would think the grey wire is audio and the two black wires are the power going to that blue thingy (transformer?)
Any idea?
Thanks

 

[Bluejets]

USB runs of the mains.
"Blue Thingy" is the mains transformer.

If you need battery powered USB, it would make more sense to get a seperate unit.
Hacking into this unit could be a major headache.

 

[FwoGiZ]

Gotcha.. I'd have to find a 5VDC I can tap onto without disturbing the integrity of the system basically right? Which would indeed be a headache.
Goddamn!
Thanks