Volts at idle with everything on (stereo, lights, acc, etc.) is at 11.4. I have an upgraded alternator, underdrive pulleys. should I get the accuvolt setup from jacobs or get a dual battery setup?

 

does it go back to 14 at speeds other than idle?

 

its fine but idle, I'm thinking the high watt headlights (european) affect it the most. Should I put relays for them? Would that help?

 

yes, put a relay in for the headlights. id check into getting like a 200amp alt, or something that produces more amps at a lower RPM

 

Other than idle, what is the voltage at the battery when measured with an accurate DVM? Say, 1000rpm. If it is between 13.5 and 15 volts you are fine. It's not unusual with a heavy load for the charging system at idle to be low. Also, most Delco alts will back down charging if the regulator senses excessive heat from high demand. If you spent your entire time ideling in traffic with all stuff on maybe it would be of concern, otherwise I would not worry about it. Don't forget, in dash guage reading takes into account wiring and connection resistance. The voltage may not be that low at the battery. Your battery is capable of delivering approx 75 amps for one hour assuming it is charged to 80-90% of capacity, and thats without the alt. If the battery is in good condition there is no need for relays, dual batteries bigger alts unless thats what you want. If you have a 100 amp or higher alt the only thing you may want to do is get a larger capacity battery such as the Optima. Another thing that really helps is to once a month trickle charge the battery overnight. Alternators are NOT battery chargers. Many times people think that there is a problem because the battery during normal service never gets charged to capacity. Loss of crank ability usually happens when the battery gets to 60% or less of capacity. If thats not happening, you are OK.

 

"underdrive pulleys" Get rid of them. It's slowing down your alternator too much. Some of the 'high end' systems I've seen have a overdrive pully on the alternator. If doesn't matter how good or big of an alternator you have if it isn't spinning fast enough.