Ive been wondering what are some of the benefits of running multiple batteries?
The reason is becuase I want to add a little more juice to my system to power the 4th 12" subwoofer I want to put in my car. These will bring me to a total of 1700watts (1600 bass + 100 mids/highs) and about of 150amps max current draw. I know they will never draw 150 amps but Im sure at high volumes and high bass notes the amps will draw around 100amps of current, right now I dont have the money for a high output alt and my stock alt puts out around 80amps of current.
Now when someones says isolate the batteries in the trunk does that mean they only power the amps and the batt upfront powers the car??Will isolated batts help maitain voltage? Does the alt still charge the batts in the back?
no real need for a high output alt OR a second battery with only 1700W, but if you are still wanting one or the other dont even consider the alt.
A second battery will allow a larger "bank" of current for the amps to tap into, and your 80a alt shouldn't have a problem keeping the charge on the batteries since you are only playing music. A higher output alt can be beneficial in the right setup/install, but they cost more than a battery and quite frankly aren't required for anything under 3kW.
I would suggest, if you dont have one already, to start with a single yellowtop under your hood and see how it works. Also be sure to upgrade the 3 wires under your hood:
Alt+ to Batt+
Batt- to Chassis
Chassis to Engine Block
After that is done, if you still have issues grab a second yellow of the same make/model and throw it in your trunk. As long as the batteries match, and you aren't planning on running the system with the car off for prolonged periods of time then there is no need for an isolator, so just wire the two batt+ together and ground the trunk batt to the chassis and you should be set.
I personally run 3kW on music with 2 yellows, and granted a 150a alt (stock), but without the 3 wires upgraded and I dont have any dimming issues at all, even at full tilt.
