has anyone noticed a big difference in a second battery?

[audiolife 5,000+ posts]

if your alt cant charge up your batteries A the alt is junk B you listen to sine waves C you dont have the battery installed right D you shouldnt try running 3500+ watts on a factory 100 amp alt and have the volume at near full volume 95% of the time

 

[12Voltz 10+ year member]

If you want to see the benefits of a second battery, you have to keep in mind that the charge/discharge rate of the battery is going to determine whether or not you will see a benefit from the second battery. Think of a battery as a bucket of water, a normal battery will only allow you to **** out a drinking straws worth of power out of it at a time. If you get specialized car audio battery, you can increase that drinking straw to a gas powered water pump. I highly reccomend a kinetik battery. Optimas not soo good. If you are going to add a second battery get a good quality battery, and USE AN ISOLATOR. If you do not use an isolator, you will cause your factory alternator to fail prematurely. I ran a 2000watt system with a facttory alternator and dual battery setup for 3 years with no power issues at all.

 

[skeptikal Premium Member]

I didn't use an Isolator in my Lumina and I ran 2 batteries for almost a year with no problems at all.

I'll be doing the same in my Impala. And if the alt fails.... it will give me a reason to buy a HO alt

 

[djjdnap 10+ year member]

yea i dont use an isolator either

 

[helotaxi 5,000+ posts]

The isolator costs you .7 V. If the point is to keep the voltage up, an isolator doesn't make sense and it usually isn't needed anyway. The charge/discharge rate is determined by the battery's ESR. Optimas are actually pretty good in that regard. Kinetics and the other car audio marketed batteries are as well of course.