The battery chart.

[cobra93 47]

I have looked at the chart you have posted many times and in the end I guess it leaves me confused.

I understand that using one battery for the vehicle will have less reserve for the stereo system as opposed to multiple batteries.

My understanding is that the battery is there as a, "buffer", for lack of a better term.

It is my understanding that the battery will deliver amps "quicker" than the alternator can react, which is why more batteries can stabilize voltage with a heavy amp draw.

I understand that the chart posted is very general in terms of what battery can support "XXX" amount of wattage.

What I'd like to know before making a decision on which battery I may need by looking at the chart, would be what are the parameters your using to make the chart?

Are you looking at maintaining a certain voltage at a specific amp draw?

If so what voltage are you considering to be acceptable?

I know that if your alternator can only produce 100 amps and the system can demand more than the alt. is capable of producing you will not "solve" the problem of decreased voltage output and an eventually have a dead alt.

I realize you are only providing a larger reserve to draw amps from until the battery(s)/alternator is overwhelmed.

At the moment I have a 2000 ford ranger. I have 4 runs of 1/0 (2 pos., 2 neg.) devoted to the stereo system.

I have a 200 amp alternator and have upgraded the alt. to battery cable to 1/0 as well.

I have no grounds using the frame of the vehicle, all connections are to and from the battery terminals.

At the moment I am powering 1> jl 300/2, 1> sax125.2 @ 2ohms and 1> saz 2000d @ 1 ohm.

I haven't measured my actual voltage drop yet, but the factory voltage gauge can drop pretty low with sustained bass output.

I know that music is dynamic and that the possible amp draw is more than the alt is able to produce if I were driving around playing tones, but I don't.

The current battery is a cheap 550 cca battery and is the only battery in the truck at the moment.

I am undecided as to add another battery or build a new tray for the largest battery I can fit under the hood.

I look forward to your response so I can make my own informed decision, not just to keep adding batteries until the problem is overcome.

Thanks for your time.

[Nathan@XSPower 47]

The battery is going to supply the power that the alternator can't. You aren't but for discussion lets say your system is pushing 3000 watts and lets say your alt is putting out 100amps at idle. So at idle you are pulling approx 350amps of power (50amps to run the truck) and your alternator is putting out 100amps. The extra 250amps of draw is now coming straight from your battery, because your alternator can not supply the extra power at idle. If you rev up the RPMs, then you will be getting your 200amps and will only be pulling approx 150amps from the battery. This is where battery power comes up big.

The chart is a general guide for the average car audio enthusiast with a stock alternator and using the system in a daily driver application staying in the 12V range.

With your application you should be able to fit the D6500 under the hood without having to make any modifications, and this would be a good power source for your system in daily driver use.

[cobra93 47]

The battery is going to supply the power that the alternator can't. You aren't but for discussion lets say your system is pushing 3000 watts and lets say your alt is putting out 100amps at idle. So at idle you are pulling approx 350amps of power (50amps to run the truck) and your alternator is putting out 100amps. The extra 250amps of draw is now coming straight from your battery, because your alternator can not supply the extra power at idle. If you rev up the RPMs, then you will be getting your 200amps and will only be pulling approx 150amps from the battery. This is where battery power comes up big.

The chart is a general guide for the average car audio enthusiast with a stock alternator and using the system in a daily driver application staying in the 12V range.

With your application you should be able to fit the D6500 under the hood without having to make any modifications, and this would be a good power source for your system in daily driver use.

That is the information I was looking for.

Thanks for you quick response!

I'll check some dimensions and make my decision.