Trakpower 4900 udc 20

[bald eagle]

Hi, I have just tried to charge my 3 week old stick pack on my core udc20. All i get it it starts to charge for approx 5 secs then it comes up with batt vol err cell low vol. the pack has been run last thursday with no problems, and stored un connected to anything, with well over 7 volt in..... It wont charge... I have a core lipo 3250 and that has no trouble. Is the trakpower goosed? HAve spokent o the shop where I got the lipo and they told me to phone flighttech, phoned them and all I get is an answer phone... .. help.