Quote: I welded a screwdriver between the + side of a battery and the fender when I shorted it out once by accident. but thats neither here nor there.
lik stumpy said and as I have been saying, the voltage regulator (and hence the alternator field) is not disconnected when the battery is removed- so no jump in voltage.
The regulator still being connected and operational is what causes the field to remain energized, this causes the alternator to keep working, building up a charge with nowhere to go since the battery is no longer in the system
the most I'll give you is that there is an overshoot of voltage when the battery is unplugged and replugged. voltage of maybe a few volts. But no way do I see damage occurring.
thats just a surge, thats not the issue
what about using jumper cables??? here you attach a battery to a car with a dead battery (dead battery with no voltage is close to no battery at all) and then DISCONNECT it after it starts.
thats a serious mistake but only determental to the car with the dead battery. Its not relevant to this arguement. It causes the alternator to work full tilt til the battery is charged. An alternator is designed to keep a battery charged, not charge up a dead one. The result will often be a burnt rectifier. Sometimes they whistle. Most people get away with it though.
so people should be blowing all there electronics using jumper cables. thanks but no thanks.
there is a possibility but minimal. Best not to do so.
same with using a big battery charger to start a dead car. Did it lots of times, never any damage.
no damage that youve seen immediatley. Seen it many times myself, and know of other knowledgeable mechanics that have. Becoming a bigger issue these days with body shops running down batteries then boosting them
never say 400v either- ever- unless the car hit a power line.
Try it and tell me never. 400 is a tad high, but its possible. 200+ is more common! try it, keep your field energized, then disconnect the output wire on your alternator. Check the alternator output with a voltmeter. rev it up. Tell me how your readings wont cause troubles!! Just like I said earlier, try it with your battery charger. It works the same way!
