Hi my ford focus 1.8 diesel wont start in the mornings, when i turn on the ignition the car tries to start (engine is turning) but the engine does not kick in. I got jump leads and connected them up to my car and another car and she will start no bother then. So does the problem have to be the battery or could it possibly be another problem? because when i put a charge on the battery she will start up with no problem. Any advice?