# Wiring a Second Alternator? Links?



## newtitan (Mar 7, 2005)

hey all, 


anyone have any links to wiring up a second alternator?

I have a dodge,and im getting different views as to whether I can just swap out the stock one for a HO alt, due to some sort of ECU voltage regulation


so just in case I CANT swap, anyone know how to add a second alternator to supply voltage to ONLY the stereo? 

and while I took circuits once in a blue mon ago, can I assume that I must also have a second battery to receive the secondary alt ouput, or can I connect it all in series to the upgraded under the ood unit?

ie stock altenator to HO alternator to upgraded Car battery ---is this possible?


----------



## maniacmech (Jul 31, 2005)

What about just wiring up a second battery for just the stereo first and see if that is enough of a voltage supply with the stock alternator.

What year and type of dodge is it?
I know some of the older ones had the voltage regulator internally in the smec.


----------



## bobditts (Jul 19, 2006)

Have a load test done on your current setup. If you alternator isnt keeping up with what you have, adding a second battery isnt going to get you anywhere. It will just create more of a load for the alternator. 

This is a great topic and am also very curious how this is done. I have a korean made car and is impossible to get an aftermarket H/O alternator without paying big bucks. I too think it would be much easier to add a second alternator. Im guessing all you have to do is get a special pully for the existing alt so you can run a second belt to the second alt.


----------



## maniacmech (Jul 31, 2005)

Wiring in a second battery will give the vehicle a larger reserve capacity.
For lack of a better term it more or less smooths the load.
I know that some heavy duty trucks use multiple batteries for this reason

If a second alternator is used it I would think it would have to be a self contained electrical system seperate from the other electrical system.

What about batcaps wired in close to the amps?


----------



## SteveLPfreak (Sep 26, 2005)

A battery is a filter and will help smooth transients but adding a second battery WILL increase the load on your alternator. Keeping that increased reserve capacity charged will require more current from your alt. Adding a second battery mainly increases your play time with your engine off.

Batcaps (depending on the model) are just high ESR capacitors and rebadged batteries.


----------



## Tirefryr (May 15, 2005)

Damn Chrysler.

Anyways, adding a self supporting voltage source for the stereo itself is a GREAT idea. You can parallel the output of the secondary alt with your current battery, but it can cause problems. The ideal situation is to have a standalone battery for this alt. Simplest way to do this is to get a unit with a self-exciting regulator, also known as a 1-wire alternator. Make sure the unit is well-grounded, run your power output to the secondary batter, and voila. 

Might I suggest a Delco unit? They are cheap, the aftermarket is huge for them, so an upgraded alt of this manufacturer will generally be cheaper. Hell, while you're at it, you may as well go with outboard rectification and regulation as well.


----------

