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The battery on my car seems recently to have become flat, i renewed it a year ago. i checked current drain on it and it showed about 0.5ma with the engine off. i charged it for 4 hours and checked the voltage it was sat at 13.5v. when i started the engine the voltage rose to 14.2 and when i put the headlights on it rose slightly to 14.4v....i cannot figure this one out, i thought initially it may be the alternator but the rise in voltage with the engine running seems to say it is ok...is it possible it is a faulty battery ? the car is only run locally and has done 60000 mls.....advice will be gratefully accepted.thanksandy

The out put voltage with the engine jogging should be 14.25 volts dc. on a 12 vdc system. this is the voltage required to maintain the charge on the battery. the rise in voltage could be a regulator problem. the voltage limiter should keep the voltage no higher than 14.25 unless it is mis-set. on solid state regulators commonly used to day about the only thing you can do is to replace it. older regulators the voltage limiter can be ad ed. additional: forgot to add, the voltage cut-out relay could be stuck closed also. if the cut-out sticks the battery will then discharge or be flat through the alternator. the cut-out relay separates the battery from the alternator when the switch is turned off to stop discharging through the alternator or generator. this is another reason to suspect the regulator as being your problem.