Second Battery?

[motoxstud 10+ year member]

i understand when you put in a second battery it gives u more amps of power, but doesnt it also give u 24 volts??? im new to this stuff so im j/w...

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[dbhittin 5,000+ posts]

A 2nd battery doesn't do much when your driving your car. Its only good if u listen to music without the engine running. Up grade your alt. first

 

[Gauntlet 5,000+ posts]

A 2nd battery doesnt give you 24 volts, it gives you a healthy 12V that is dedicated to just running your stereo, and when combined with a 2nd alternator it provides you a healthy 14.4. As dbHittin said, its pretty pointless unless you listen to your system with the engine off a lot

 

[2theMaxx21 10+ year member]

If you get a second battery, I would recommend getting a dual battery isolator (Orion makes a nice one). When the engine is off your sound system will pull current from only one of the batteries, which will leave the remaining battery to start your engine. Once your engine is running, the battery isolator will switch modes and allow your alternator to recharge the battery that was drained down while you had your ignition off. I would recommend getting a beefed up alternator if you plan to do this, because the alternator will be charging 2 batteries, which is an added load on the alternator. A stock alternator won't last very long with a dual battery setup.

If you're interested, I have a nice Orion dual battery isolator that I might sell for $100.