I use a USB extension with the standard charger while playing and charging and the control will randomly turn off. At times when I check to see how much power it has on the XMB, it shows " - ". Is there a reason why this happens? Perhaps using the extension cord? I usually end up charging the control on the PC. Does that affect it?
I'm going to be helpful. Welcome to the forums, too. You should check how solid the connections of the cables are, if they're wabbly and loose, you might want to tighten them up. You should also make sure they're clean and free from dust, as that might also affect the contacts on the connectors. Other than that, try different cables and failing all of that, take it back and ask for a new one.