Voltage drop (need major help and input!!)

[Platinumzs1k]

Running a T1500bd-cp and a 4 channel that's like 200 rms at best!

the Rockford T1500cp is a little more than 1900 rms... i have a kinetik 1800 and 600 a interstate battery under the hood.. 2 of the big 3 done. zero gauge wire too. current alt is stock 130 amp

i have voltage drop after like 3 songs. my voltage starts at like 13.8 and after u play it for awhile it goes down to 13.3 or 13.2 and stays there for awhile.. the bass gets noticeably weaker after a few minutes of play. never does the voltage go above 14...never!! how is this possible...i hop in random people old cars with the stock volt meter and it read above 14 and there nothing aftermarket in there...like wtf!!!!!!!???

all i can do is switch my rear battery bank ground wire to zero and do 2 runs and finish the big 3 which would be to run the 0 gauge to the alt...after doing this i really don't see the problem being solved. is the alternator the answer?? i have heard some stories of people with batter batteries than me and a very high output alternator (excess of 350!!) and they still had voltage drop with not that much rms to be honest... im basically worried that the alt wont do it..

if i get an alt i don't want to spend that much money.. like 250 or less if possible. I NEED SUGGESTIONS!!!!!!!!

also how do you get your system to the point where when the bass hits you lose like .1-.4 volts...??? how do these people do it...plus with more watts than ill have.. i need help please.!!!!

[Platinumzs1k]

bump...

[tonedeaf]

So are you dropping down to what, 13.2? Thats not a lot of voltage drop for pushing somewhere between 1200-2k watts of power. Big three btw...do the 0 gauge alt run ASAP. The big 3 really doesnt do ANYTHING with only the ground wires done. The big thing is having the most power with the least resistance from your alt to your battery. Also, is the interstate 600 battery in the back a sealed AGM battery? If not, then it may not be helping your system much, as mixing AGM and non is ftl. Simply put, you dont have the electrical to get up to 14 volts with the system playing. Some cars are also PCM controlled so your voltage wont go above what the computer tells it to.

You didnt specify WHAT you're dropping down to on voltage though. If its as far down as 13.2 you really dont have an issue. If it drops far below that than your amp is probably clipping to shit and pulling loads more power than it should, one of your batteries is bad (remove the non AGM one), or your alt could be going out or is putting out only 60-90 amps out and simply cant keep up (which is likely).

Edited July 19, 2011 by tonedeaf

[tonedeaf]

Also, those 'stories' that they were having terrible voltage drop with 350 amp alternators means they did something wrong. If you're pulling only 2kish watts and you have a good AGM battery and ANY quality H/O alternator, your voltage should be rock solid.

[Platinumzs1k]

when the bass hit the volts go down to low 12's and some songs 11.5 and up ... which is bad..

amp gain is 25%

interstate battery it the megatron 47 and its the biggest battery i can fit and its under the hood.

i probably need to get a better alternator plain and simple...but how much are they and who makes good ones for my needs?

[tonedeaf]

For a good H/O alt you're looking at minimum $400...more towards $550. I wouldnt run anything but DC power or Mechman for alts. I have not had experience with either YET, but both make high quality alts and have loads of people on this site and others to back them.

As I said though, upgrade your alt power wire asap. That is definitely holding you back, much more than you might think. After that, upgrade your ground wire on your rear battery. This is also hurting your system. Your ground wire need to ALWAYS be the same size as your power wire. If you can, you need to run a separate run of 0 gauge from your front battery to your rear. This has been proven to increase voltage and even the TL score in several different builds I have seen.

Edited July 19, 2011 by tonedeaf

[tonedeaf]

You can also go to your local dealer or autozone and have them check both batteries and run load tests on them to see if they are functioning properly or either have a bad cell. Might not be the case but its possible. Your alt might also be going bad, we dont know. You can also have it tested if you took it into autozone. Where is your ground for the battery in the back, and what about the 2 you supposedly have done for the big three? Did you sand these points down to bare metal?

[Platinumzs1k]

all bare metal.. my rear bank is connected to the front by 0 gauge and my rear bank is grounded by 4 gauge... would 2 runs of zero help alot back there or is one enough? its like a one foot run.

[tonedeaf]

Two runs would help, but one run of 0 gauge will be best. Take a DMM and measure your rear battery voltage. Remember that number. Now with the positive still on the battery positive, test the grounding point. If your voltage is less at all than you dont have a strong ground. Replace the 4g with 1/0 should help. 1/0 from front to alt will def. help unless your alt is bad. In which case it might still help, but the failing alt is your main issue.

Edited July 19, 2011 by tonedeaf

[Rebel4055]

all bare metal.. my rear bank is connected to the front by 0 gauge and my rear bank is grounded by 4 gauge... would 2 runs of zero help alot back there or is one enough? its like a one foot run.

So your running 1/0 then just decided to ground the rear with 4?