Car Stereos: car audio, gauge wire, smart idea

Question
By me having a battery in the trunk running to my amp will it stay charged while its just hooked up to the amp alone? Will it get power from anywhere else to stay charged? So the thing is I have one under the hood running the car, then I have one in the trunk running the amp. Is good to have it like that so that it won't run down the battery to the car?

Answer
Hi Tre,

If the new battery is hooked up to the car's factory charging system, then it will be charged along with the rest of the system.  Adding another battery for the stereo is a very smart idea, and is often a better choice than a simple capacitor.  The battery in your trunk will also be used by the car for other purposes such as starting in the event your factory battery dies.

With this in mind, you'll want to keep an eye on the voltage of the two batteries separately because having ONE battery die will be less noticeable.

Also ensure that you have a heavy enough gauge (at least 4 gauge) wire running to the rear battery as a LOT of amperage has the potential to be flying through it.

Justin