I've got one of these things: http://tinyurl.com/2ps5k4
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?