When do I need to upgrade my alternator in my car.. for my car audio system? How to calculate it. 

Good video man.

Thak you Josh for this helpfull video. Keep teaching us.

Thank you for this video

When you talk watts, are you talking rms?

I've been trying to figure it out for weeks now. I want to add a second battery. I'm running a 2500 W amp with 2. 12. I have done the big 4 upgrade. But I'm just not smart enough to figure out what kind of battery I need. I cannot get nobody to give me a direct answer. And it is driving me crazy. I drive a 2007 Kia Ronda. And I'm running a Pioneer head unit and Both of my twelve are rated for twenty five hundred

Only if your system exceeds the cars electrical demands... I would still do a big 3.