additional battery for car audio?

[shaunb]

i'm upgrading my audio system in my nissan . I'm thinking of adding an additional battery in the trunk.My question is, can my stock alternator charge this battery and if I need a voltage regulator .The battery will be a optima dry cell and it will be completely isolated electrically from the cars' electronics.

 

[deonejuan]

I've been there, done that, got the t-shirt. Modifying the battery/alternator/regulator becomes a maintenance item. Too much alternator and you fry the car's harness. The alternator, if it fits the engine compartment's mounting brackets, will pull the engine down. A truck will have room enough that you could parallel two auto batteries. You get a 2nd battery kit at an RV center.

 

[MDC]

Why do you want a second battery? Do you think it will help with your headlight dimming/other power issues or do you want to run your system with the car off longer?

A second battery is not needed for your system nor will it make your electrical system better. A battery is an energy storage device. You only need it to start the car or run electronics when the car is off. When the car is on your battery plays a very small part in the charging system. Your alterantor is what produces the power for all the electronics in your car. That is what you would want to upgrade if you had a large system.

Adding a second battery will put more of a strain on your alternator. Now your alterantor has to charge two batteries instead of just one. That will greatly shorten the life of the alternator is it isn't sufficient. It could also shorten the life of your batteries because they may not be charged enough.

If you only want additional listening when your car is off then it would be a good idea to get a second battery. However, you may need a high output alternator as well. It depends on what size alternator your car has stock and what size system you are running.

Good Luck!!!

 

[jaes91]

As already said get a H.O alternator. It is the best thing to do but it depends on what kind of wattage your system is and how many amps you are drawing. There are equations to calculate your amps.