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I am running 2 Viper 1200's and Viper 200.4 in a 2004 Dodge Durango. I have an 1100A Rockford/Exide Orbital Deep Cycle Batt under the hood, i did the big 3 in 2/0awg, I have a 1 farad cap, and i just got an Irragi 220A alt, 150A at idle. However I am still having voltage drops at idle. I will put a strong bass line on and the voltage on the cap reads 10.5v and my batt light comes on. My batt light does not turn off until i turn my system down. What else do i need to be able to bump my music without having to worry about my voltage dropping? Would an extra batt or batts help the situation? I am looking to keep my voltage at around 12-13v while bumping it full tilt at idle.

a few more batterys. those vipers arnt very efficent so they draw alot of current. also are you sure your alt is working properly? that 220 amps should be sufficent to sustain that with out dropping to 10.5 call dom and check with him. because my voltage will drop to 11.6 with a single deka and a 200 amp alt from excessive.

i'm not to knowledgable about this but heres what i think.

Extra batteries really do nothing. Batteries are just prety much for runing music when the car is turned off from what i hear. (please correct me if i'm wrong, i live to learn). If your at a show and want to bump your music wihtout runing the car its nice to have a seperate batery (deep cell so it can be recharged over and over).

The caps are really crap. They do nothing. Caps are made as a bandaid for a bad electrical setup. They only hold so much charge. If your system keeps hitting musical peeks and draining power its just gona drain that farad right out and before it can recharge keep sucking more juice. Especialy the 1 farad caps from what i here arnt built that great. If your looking for a true cap thats good and may help some i here alumapro 5, 15, and 50 farad caps are great and are built with true capacitor components that the military uses. (not paper like the 1 farads, still a bandaid tho)

What i think is your alternator at idle still isnt powerful enough. i'm asuming that d1200 has probably 100-120 amp max draw each (add up your fuses), not to mention that 200.4 which is probably max 30-50amps. thats 260 amps at the least max draw (assumption here) Your probably not drawing full amperage cuase of all your settings on the amps and loudness your playing your system so while your driving you wont see any voltage drop. While sitting still, theres essentialy nothing you can do. Unless your worried just about at lights or a short period of time a big farad alumapro cap might do. but if you want to sit around at a show and crank it and want no voltage drop, its not going to happen without a 2nd HO alternator. I've seen it. People make custom fitments. Lota work but can be done.
This is alot of assumptions here and if i'm wrong on anything as i said before please correct me. hope this helps :happy055:

In a situation like this, where at idle your not getting enough current, couldn't you overdrive the alternator a bit? Meaning a little bit smaller pulley? Bill you tried that before?

his alt amperage is fine your not going to get much bigger than that and hes only running about 2600 watts. 220 amps should be fine it seems to me that the alt is not working properly. you can try a smaller pulley but he already has an upgraded alt and the pulley is specifically designed for that alt. any change could result in catastrophic failure or less current than its already putting out.

Extra batteries really do nothing. Batteries are just prety much for runing music when the car is turned off from what i hear. (please correct me if i'm wrong, i live to learn). If your at a show and want to bump your music wihtout runing the car its nice to have a seperate batery (deep cell so it can be recharged over and over).

This is incorrect a second third or even fourth battery is beneficial only if you have the alternator to support it which he does. (although I don’t belive its working correctly as stated above) I run 2 batteries in competition (only 2 because that’s what my class allows.) because I can draw much more current than I could with a single batter on top of that the second battery is withing 6 inches of my amp. Again this only matters if you have the alt to support it.

Wouldnt you want to keep say 14.4 volts? i would think your altnernator would keep this amount of current flowing so it wouldnt have to dip back out to the battery? Or are you constantly drawing power from the battery even after the car starts? Prety new to this electrical portion, evertying prety much was assumptions from what i've overheard people tlak about here and there. Could you explain a bit more about that bwcad1?

When your car is running, you're probably running consistently more around 13.6v. Idle is probably slightly lower, between 12.5v and 13.6v. It depends on the alternator.

I'm not sure if the battery is actually used as like a reservoir once your car is on and than is simultaneously recharged or if your car runs straight off the alternator and then dips into the battery when it needs more than the alternator can put out at once. In any case, if you try to draw more than your alternator can put out, it will use charge from your battery.

Bwcad1 wrote:his alt amperage is fine your not going to get much bigger than that and hes only running about 2600 watts. 220 amps should be fine it seems to me that the alt is not working properly. you can try a smaller pulley but he already has an upgraded alt and the pulley is specifically designed for that alt. any change could result in catastrophic failure or less current than its already putting out.




This is incorrect a second third or even fourth battery is beneficial only if you have the alternator to support it which he does. (although I don’t belive its working correctly as stated above) I run 2 batteries in competition (only 2 because that’s what my class allows.) because I can draw much more current than I could with a single batter on top of that the second battery is withing 6 inches of my amp. Again this only matters if you have the alt to support it.

Bwcad1 is correct, but don't misinterpret what he's saying. For an average person that almost exclusively plays their system while the car is running, you need to be looking at a HO alternator to power your system. For competitors, the multiple batteries are needed because many competitors are required to keep their cars turned off to compete. In the competitors case, the alternator actually doesn't matter until it's time to turn the car back on, which is when the batteries begin to recharge.

solacedagony wrote:When your car is running, you're probably running consistently more around 13.6v. Idle is probably slightly lower, between 12.5v and 13.6v. It depends on the alternator.

I'm not sure if the battery is actually used as like a reservoir once your car is on and than is simultaneously recharged or if your car runs straight off the alternator and then dips into the battery when it needs more than the alternator can put out at once. In any case, if you try to draw more than your alternator can put out, it will use charge from your battery.

Correct but most cars sit anywhere from high 13s to low 14s mine sits at 14.6. the alternator runs the car the battery is just there to start it and is charged by the alternator. dont forget music is dynamic. for instance your not going to constantly draw 150 amps it may go from 20 - 60 - 35 - 175 then back to 60 your alternator will absorb most of the amp draw however if it cant supply enough current at the time the system will draw from the batteries this is where the larger alternator comes in. during the lower amp draws like the 20a draw it will recharge the battery/s so then the batterys are back at full charge when the next large draw of current comes.

solacedagony wrote:Bwcad1 is correct, but don't misinterpret what he's saying. For an average person that almost exclusively plays their system while the car is running, you need to be looking at a HO alternator to power your system. For competitors, the multiple batteries are needed because many competitors are required to keep their cars turned off to compete. In the competitors case, the alternator actually doesn't matter until it's time to turn the car back on, which is when the batteries begin to recharge.

extra batteries are for more than just this. see the reasons stated above. extra batteries are always benificial as long as you have the charging system to back it up.