Alternator load dump protection

Hey everyone, just have a quick question about alternator load dump protection! My car has a thick 2/0 awg battery cable that runs underneath the car, to the jumper cable post, where the starter motor gets 12v power from, and where the alternator sends 12v power back the battery. All of my sensitive electronics, and really everything that's powered in the vehicle has 12v power from a another 12v battery cable, that's fused, and distributes the power throughout the vehicle - fused.

My question is, when the car is shutoff, and the alternator stops putting 12v battery out and creates a voltage spike, will the battery absorb the voltage spike from the alternator load dump? The cable underneath the car where the alternator is connected to, is always hot, and will not disconnect unless it gets cut during a crash or something. What about my other 12v battery cable that connects from the battery directly, to my custom power distribution box?

Maybe I'm not understanding load dump correction, but I believe there's no load dump if the battery is always connected to the alternator - is that correct?

Thank guys!

Michael

You are correct. Connecting the Alternator output directly to the battery avoids the issue when the battery disconnect is activated. However some rules do not allow the Alternator lead to remain "hot" when the master switch is off. That is why there is a load (high wattage, low ohm resistor) connected when the master is switched off in those cases.

In a standard setup, the battery absorbs any voltage spikes and acts like a large capacitor. A true alternator load dump only happens if the battery gets disconnected while the alternator is still charging, because the field collapses and the voltage has nowhere to go. That’s why it mainly happens with kill switches or isolators. If there's a constant connection from the battery to the alternator, you don't need to worry about load dumps.