These lithium battery packs have integrated computer circuitry that communicate with the charger. When the battery is so stone dead that there is not enough power to turn on the computer, the charger will not charge the battery and indicate a fault. By supplying the battery with a little charge by jumping it, you facilitate the computer's operation and the charger charges the pack.
another way i got around this (and i don't know why this works but it has twice now). is that i plug in the charger and then add the battery to get the red/green flashing for a few mins. then unplug the cord while keeping the charger and the battery together. Then after a few mins i re-plug in the cord and it usually starts to charge the battery
