Dell KJ321 Slice Battery Issue

Hello, I have a Dell Precision M6600. I recently purchased a KJ321 Slice battery, however when charging it the light blinks amber-off-white-off repeatedly and never seems to charge. But if I charge it through the computer It charges but is not detected in the BIOS or windows, so I don't know how much charge it has, it only knows when it is low on charge, taking out the main battery doesn't make any difference. Does anyone know what could be causing this or how to fix it?