Originally Posted by
benshere
Are you aware that a battery charger that is capable of 200 amps puts out MUCH more voltage than 12.5 VDC?. I mentioned this in another thread. In order to push 200 amps through a charged 12 V battery and a 12V system, the voltage would have to be (just a guess, but your charger info should tell you) considerable, like maybe 30-50 or more VDC. Voltage is what drives amperage. You cannot get an increase of amperage in any given system unless you increase voltage or decrease resistance. That is part of the Ohms Law formulas.
Given that, you may well have damaged some electrical components. For example, some cheap diodes may have a PIV (peak inverse voltage) threshold that you exceeded, which would probably blow them. Not saying thats what happened, but it is clear to me that you did something to the electronics. No doubt about it, the excess voltage caused excess current flow through the breakers/fuses and tripped them. I am curious why you didnt blow and fuses----maybe you did.
Reasons like this are why they tell you to disconnect the ground cable when welding on vehicles.
I would say your wrong with your example. We run 200 amp alternators on tractors with 12 volt systems all the time. These alternators don't go over 14.5 volts to induce 200 amps of current under a heavy electrical load. These tractors will use up to 14 onboard computers depending on attached options, so they closely monitor system voltage and have protection parameters to guard against voltage spikes. The automotive industry uses the same protection systems.
Just because you set the charger to a 200 amp setting doesn't mean it will automatically put out 200 amps. You would need to be cranking the engine with a dead battery to get the full 200 amps out of the charger.
The over voltage protection system on the vehicle probably shut power off to the computer which has the drivers in it that controls the windows. The same thing would happen if your alternator regulator failed allowing the alternator to overcharge.