underground_army wrote:well i just thought about it im not going to do it and just that people that have big systems and i mean BIG i thought would it drain the crap out of the battery im new to the whole system thing i am just learning about audio
I got ya. You said radio..... not some "huge" system. Batteries are for starting the car and using accessories while the engine is off but key on. The alternator is what your vehicle and accessories run off of when the vehicle is running. Once the car is started, you could actually take the battery out and it wouldn't be needed. So if you have a system big enough that draws more current than your alternator can supply, then it will start to draw from the battery(s). In this scenario your alternator could burn up prematurely. Adding a second battery is only a band aid. You could even argue that the second battery could be even more of a strain on the alternator. Because if you are over drawing from the alternator, then the batteries are losing charge. Once your music dies down a little where it's not such a strain on the alternator, then now the alternator has to charge "2" batteries back up instead of just one. Also, capacitors do not supply power to your vehicle's charging system. They only supply instantaneous burst of current for bass notes to reproduce them properly. They are nothing like a battery! So the real solution for a high current drawing system is a bigger alternator.... plain and simple.
Toby