Went from 2ohm to .5ohm, voltage crashed

[Buffalohed 10+ year member]

Today I rewired my quad 2 vc sub from 2 ohms to .5 ohms, on a Sundown 1500D.

With the sub at 2ohm, I was able to play full tilt and hover between 13.5-13.6 volts. Now, I tried to slowly crank it, and the voltage dropped all the way down to 10.8 not even close to all the way cranked. As it is, the sub was incredibly louder than previously, but where 28/35 +15 was my previous "cap volume" I had it at I think 24/35 +9 when the voltage crashed.

I have 0/1 big 3, 80amp stock alt, 0/1 power and ground runs, and an HC2000 in the trunk. My hood battery is a shitty Autozone batt. Do I need to upgrade my hood batt like to a Yellow Top to see the full potential of my electrical system? I don't know why it was dropping so low with a 2250 amp battery in the back, but obviously something is either wrong or needs upgrading.

Thanks for any input.

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[Twistid 5,000+ posts]

are you getting dimming?

im running my sundown @ .7 and i dont experience any dimmage at all, although ive yet to hook up a dmm to it to check my voltage

i have a 100+ amp stock alt, hc600 in the back, and 1/0 runs

 

[937DYTBOI 5,000+ posts]

upgrade the alternator quick

 

[Buffalohed 10+ year member]

Yes, I was getting very bad dimming even before I rewired the sub.

Another question I thought of, as long as I keep the sub level down so the voltage is around 13.1 or higher, the low resistance shouldn't damage my amplifiers, right? I plan on keeping the sub hooked like this daily unless it is totally advised against after I upgrade my hood battery.

 

[Twistid 5,000+ posts]

your getting major dimming? thats strange...

im not getting any AT ALL ... and you have a 1/0 big 3 + a huge *** battery in the trunk...

 

[blackbonnie 5,000+ posts]

but he also has an 80 amp alt, which definately doesn put out 80 amps at idle. i say first thing you do is scrap you alt, and upgrade quick, before you seriously hurt something electrical from no power. and then upgrade your hood battery, but alt FIRST.

 

[Twistid 5,000+ posts]

dident know there was that much of a difference between an 80 amp alt and a 100+ amp alt (most likely around 106/109 amps , v6 mercury)

edit:: **** nevermind its a 130 amp alternator , HELL YA FOR MERCURY!

 

[djman37 5,000+ posts]

at 10v, your batt is discharged. something doesn't quite add up though.

 

[Buffalohed 10+ year member]

I'm gonna run out and grab a Yellow Top. Alternator is gonna have to wait a week or so no matter what, I don't have the funds for one right now.

 

[audiolife 5,000+ posts]

what is the resting voltage of the battery in back?

 

[blackbonnie 5,000+ posts]

i say if you have the money to go out and buy a yellowtop right now, how about unhook your system for a week (i know its hard) and save up some cash, and throw in a h.o alt. it will be worth it. i mean do whatever you want, but you might still have the same problem with a yellowtop just not as bad, no as with an alternator it would keep both of your batteries charged completly and alot better then your stock one. its your choice though

 

[Twistid 5,000+ posts]

ya dude, if ur alternator cant keep ur batteries charged as it is, another bigger one isent going to help anything //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[xtremesplokc 10+ year member]

First of whats an Hc2000? sorry to lazy to go look around lol but anyways first, what is the rest voltage of the electrical system, and than whats the rest voltage of the front and rear batteries independently, honestly sound like one or both of the batteries are bad. Im running a 160a alt, 2 optima g31's, and 4 runs of 1/0 and i daily drive my memphis 4kw @ .4 and i never drop below 11.9 when i play full tilt. And honestly the alt is a pos that prob isnt rly putting out 160a so im mainly relying on battery than allow the batts to recharge after i let off of it.

 

[canadapettit 10+ year member]

its a big kinetic battery

 

[Buffalohed 10+ year member]

Thanks for the help guys. I bought a Yellow Top, which I was planning on doing anyway, but haven't tested it yet.

Next week I'll be ordering an alternator. When I get a chance I'll test the voltage of each battery.

Thanks again.