2 alt, 3 batts, and still dropping like crazy...

[boostNbeer]

I think I may have some electrical trouble here. Ive been having some troubles with voltage drop since I upgraded. Heres a pics of its setup for reference if anyone sees trouble

I used to have the factory 100amp alt, and an optima blue top main battery. Worked great for 1500rms

Then I bought a Visonik V4000XD and am running it @ 1ohm

So to back up the power I would need for that, I went and grabbed 2 NSB90 batteries, and put them in the back of the truck, along with 2 2/0 cable runs to the main batt. ALL cable is 2/0 welding cable, big 3 aswell. Didnt work, voltage was still dipping into the 11's not even on full tilt (amp would protect @ 11 volts)

So for the last week I went and bought a 200 amp alty and installed it in my car ALONG WITH THE FACTORY ALT. So 300+amps @ 2k rpm.

BUT STILL, voltage drops just as fast, drops like a rock as soon as any hard notes come on. Almost like the 2nd alt was never even added....

Im pretty stumped as to whats going on, I know the visonik makes 3kish rms and I have close to 1k rms for mids. But it is dropping this low without even going full tilt, it usually cuts off at about 17 of 40 volume....

Only thing I can think of is my rear batterys ground possibly? They are grounded to the floor from a factory hole, but still sanded bare etc.

Click to read more...

 

[michaellane 5,000+ posts]

looks right???

 

[basscort2009 5,000+ posts]

add a ground to your alt and your back battery. and make sure there sturdy as shit. sanded down. metal to metal and bolts not self tap screws

 

[boostNbeer]

Add a ground to my factory alt? and add a ground to my 2nd back battery that ties over to the other rear batery ground?

They are bolted, there was a factory "tie down" bracket with an M6 bolt, so I removed the bracket, sanded down to bare, and bolted all the grounds (my 2 amps are grounded there aswell) to that point

 

[basscort2009 5,000+ posts]

yea cuz right now you only have 2 ground points for 2 batts and 2 alts. ground factory batt and then back batt.

then make sure the gronds all go to the frame, not sheet metal

 

[boostNbeer]

yea cuz right now you only have 2 ground points for 2 batts and 2 alts. ground factory batt and then back batt.
then make sure the gronds all go to the frame, not sheet metal

The floor kinda is sheetmetal... I could always cut a hole in the floor and ground to frame... but thats excessive to me, plus I would need 4 1" holes....

I dunno if you caught my last post, but Ive got 2 batts and both my rear amps grounding to that point in the rear of my car.

Im down for doing whatever will help, but you think that will make much of a difference?

 

[davey2020 10+ year member]

Try getting the alternators tested maybe ones not working. Maybe get your batteries tested as well, one might have a bad cell. Cause i got about the same power as u and i don't drop bad like u do, i usually stay around 12 volts at full tilt on stock 70 amp alternator. sounds to me like your 200 amp alternator isnt working to good.

 

[boostNbeer]

Well the oem alt was all by itself until 2 days ago, and worked just fine. And the 2nd alt is BRAND new. The 2 NSB 90 batteries arent more than a week old

The main blue top optima is a good 18 month old though

 

[davey2020 10+ year member]

i would get the alternators tested i bought i brand new 200 amp alt that lasted me like 3 days lol just cause its new doesn't mean it cant be defective. i friend of mine went through like 3 brand new alternators cause they were defective and he didnt even have a system lol.

 

[boostNbeer]

Anyone else got more ideas to spit at me. Im all ears at this point. Spent 2k in the last month on something that dont work //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[boostNbeer]

I should probly also mention, the + output connection on my HO alt, was an M6 stud like 1/2" long, couldnt fit all my 2/0 lugs on there, so I made a little aluminum block, tapped an M6 thread in it and spun it onto the post, then tapped a 5/16" thread in it and bolted all my connections to the block. SO there is a 1" chunk of aluminum between my alts + output and the actual connections if that matters..... pretty sure aluminum is perfectly fine though

 

[gtbike900 10+ year member]

its kinda the amps falt my truck hated my 2 cdx 20a clif designs same as your 4000 switch to sundown and its much better but i also have 3 0ga run and 1ga run of ground 1 off each alt and one to the front battery big 3 and all grounds are on the same place on the frame

 

[boostNbeer]

You lost me on that sentence

 

[k_schutte 10+ year member]

looks pretty good to me... your voltage drops are pretty crazy IMO, I was running a Memphis 4Kw and a CRUNCH P1800.4 with a single O.G. 300A alt and a pair of BatCap 2Ks and never dropped below 12.8~ then I did the big three and don't recall ever dropping below 13.6~ full tilt at the comps...

what is your resting voltage at the amp with the car off? what about with the vehicle running but with the stereo and everythign off? I have had a couple brand new alts quit on me within minutes of putting them on just for the record... Then I decided to stay away from Iraggi and haven't had any problems since LOL...

I would disconnect your factory alt. and see what you got for voltage... Then tell me the *****es name ;-)

 

[gtbike900 10+ year member]

ygpm