Hi, my battery on my tigra 1.6 1995 keeps going flat overnight. It is a brand new battery. I charge it fully, then overnight (without even using the car) it goes flat. I suspect that some component is taking charge when ignition is off. All the lights are off (& radio etc). The car will run with the terminals not connected so i dont think its the alternator. How can i check what is wrong? please help ...thanks