I was helping my buddy work on his daughters car. Battery was discharged, so we will pulled it and charged overnight. Performed two tests on it after 12+ hour charge. Specific gravity test indicated all cells being marginal (yellow) as did the load test. We reconnected the battery, started car, lifted one battery lead, and engine died. Bad alternator, right? He took car to his 'wrench' as we don't work on 'sideway motors'. His 'wrench' said two strange things...never lift the battery lead on newer cars as this puts high voltage AC on the electrical system. Also, he said you have to let the battery rest after charging before taking a specific gravity reading. It will read low otherwise. Is this correct? Thanks
