I've got one of these things:
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i.e. a microprocessor-controlled "smart" charger.
Been disconnecting the batt before charging just on GPs - having blown a couple of alternators giving somebody a jump start.
The device has an "alternator good" indicator light on it... so I'm guessing there's some built-in functionality that purports to evaluate the alternator without damaging it.
Am I wasting my time by disconnecting the battery before charging?