Try jump staring the vehicle again, once started leave it connected to the other vehicle (TURN THAT VEHICLE OFF). Monitor your battery light...........you may see it dimly lit. If that is the case then a regulator may cure the immediate problem, however you need to investigate the armature prior to making that commitment. If it is deeply worn than an Alternator is a better choice.

If the light is not dimmly lit while running than your battery may be the suspect.