Lupo gti had it 3 days and went to go to work in the morning and was sluggish on the key and wouldnt start...then the hazzards wer going off so i disconnected the battery and took my van to work, came home later that day with a jump pack and with that it started up.....checked the battery and thers no drain on it and the battery tester is sayong the battery is good....some days it starts perfect then other days it wont but allways goes with a jump....any clues