Touch Pro don't charge when running GPS softwares

[hksmr2]

Hi all,

This is my first post, and i would like to say that you guys all rock, I learn so much from every1 here. My problem was the past weekend I made a road trip from NY to Boston, so I used my Touch Pro with Garmin XL installed as a GPS, I left it plugged in so on driving for over 2 hours my phone started beeping say low on battery so I pull over and checked it was plugged in completely so I exit out of the program, and it was charging, but once I launch the program again it didn't charge, any idea or suggestions?