Voltmeter on battery before start=12.6V after start=14-15V. More than that=overcharging. Also you could have a leaking or bad battery. Sometimes they do "blow up". Especially if they get HOT! and Smell!! Give it some high idle to see if charge goes over 15V.

Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn