Acceptable voltage loss

[sacsking916 5,000+ posts]

Just an //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif I run a regular stock batt up front off my alt with 2 agm batts in the rear. I never paid much attention to the whole front battery has to be an agm. Its recommended but not needed if you're using a battery in the back. If you're trying to keep it on one batt then get a big agm or equivalent

 

[KTMrida4life 10+ year member]

Got it hooked up tonight about an hour ago. Its kinda rigged. It works, but the main thing Im worried about is there is no fuse on the power wire, so its kinda sketchy. I unplugged the power wire (left the ground hooked up) and wrapped electrical tape around it for the night as I dont want to find out my car is on fire during new years.

It is LOUD. I havent even really tuned it yet, I tried to set my gains with a DMM but Im not sure I have them set correctly, Ill check tomorrow. I cant believe how much **** is still rattling after sound deadener. Im either hearing something rattle inside my box (maybe port noise?) or the plywood in my trunk is vibrating... or the ground wire is vibrating. Whats the best way to stop the big 0 gauge wire from rattling on metal?

Also.. about the voltage drop. I have NOT done the big 3 upgrade yet. 150A amp (stock is 90) and duralast gold battery.. I can only go to about 35 before I start seeing massive voltage drop. If I go to 40, it may dip below 12V just a hair and I can see my interior lights dim a bit when it hits. I dont even have the gains on the amp all the way up yet.

Guess I need to do more electrical upgrades. You were right mast240. So what now? Add an AGM battery to my current acid battery or what?

 

[mast240 10+ year member]

Big 3 is your first step.... it really does make a HUGE difference. i wouldnt do anything before doing that. after that, if your still having massive voltage drop, then it's time to think about a second batt.

also, i'm not sure if it's your power wire rattling, but if you want to be sure, you can get wire straps at your local hardware store, and use those to secure it to the box, trunk, where ever you want.

 

[KTMrida4life 10+ year member]

Big 3 is your first step.... it really does make a HUGE difference. i wouldnt do anything before doing that. after that, if your still having massive voltage drop, then it's time to think about a second batt.
also, i'm not sure if it's your power wire rattling, but if you want to be sure, you can get wire straps at your local hardware store, and use those to secure it to the box, trunk, where ever you want.

Could it be my box rattling? I cant imagine it would be with as many screws I put in it..

My rear bumper sounds like it is going to fall off. I think Im going to take it off tomorrow and put some AT on the backside of it.

 

[mast240 10+ year member]

Could it be my box rattling? I cant imagine it would be with as many screws I put in it..
My rear bumper sounds like it is going to fall off. I think Im going to take it off tomorrow and put some AT on the backside of it.

i doubt it's your box rattling... there's alot of areas in a car that can rattle... rear deck is a big problem for most. headliner can rattle pretty badly, if the car has ever had it pulled (like sunroof work, or ***** like that), door panels, pretty much anyplace in the car where plastic touches metal will tend to rattle

 

[KTMrida4life 10+ year member]

i doubt it's your box rattling... there's alot of areas in a car that can rattle... rear deck is a big problem for most. headliner can rattle pretty badly, if the car has ever had it pulled (like sunroof work, or ***** like that), door panels, pretty much anyplace in the car where plastic touches metal will tend to rattle

Sounds like it is coming from the trunk area.

But thats not the major problem, I cant even hear that in the front seat. I am having some MASSIVE rattles somewhere because when I really turn it up, its all I can hear. I know some of it is from my rear deck, Im putting the AT on there tomorrow as well.

Gonna need more of that stuff.. I havent put any on my trunk lid either. Scared of how it will look.. so I may spray it with the liquid stuff instead.

 

[KTMrida4life 10+ year member]

Took an hour or two but I put in 3 new wires, all 0 gauge.. what took so long was soldering the ends. Ground -> car, ground -> engine block, and 12v from alt to batt. Really wanted to make sure its a secure connection so I had to find a massive soldering iron (couldnt find torch) to solder the ends.. but theyre sturdy.

I had never looked real hard before, but the power wire from the alt to the rest of my car seriously looked like either 10, or 12 gauge. It wasnt 8. Tiny little wire.. I left it in place, and added the other wire on top.

So.. now when driving, playing with the volume at 40/50 and my amp at roughly 1500-1600W, Ive only seen it drop down to 12.9V. Much better.. a whole 1.5V better because I accidentally made it hit 11.5V once before the upgrade. My interior lights dim just a bit, I'm not sure if my headlights do..

So as long as I dont ever hit 12.5V or below, am I safe? Im a nervous wreck right now because my amp power wire is hooked up without a fuse because I dont have a fuse holder. Im scared my car is going to be on fire when I look outside, and now its raining. Im going to unhook it tonight before I go to bed...

 

[CAT MAN 5,000+ posts]

i rest at 14.6-14.8 and anything over 1.7v drop is bad IMO

 

[mast240 10+ year member]

12.5 is acceptable, but to be honest, if your seeing that much drop while driving (not at idle) you're going to want to add a lil to your electrical, just to be on the safe side. Main reason i say that, is that while 12.5 is acceptable, you could easily still drop down in to the 11's when idleing, or under heavy play. a second batt should be able to keep you in the 13's while driving

 

[CAT MAN 5,000+ posts]

12.5 is acceptable, but to be honest, if your seeing that much drop while driving (not at idle) you're going to want to add a lil to your electrical, just to be on the safe side. Main reason i say that, is that while 12.5 is acceptable, you could easily still drop down in to the 11's when idleing, or under heavy play. a second batt should be able to keep you in the 13's while driving

b i n g o and bingo was his name O..... i dont see under 14 most days at 2200 rpm

 

[KTMrida4life 10+ year member]

12.5 is acceptable, but to be honest, if your seeing that much drop while driving (not at idle) you're going to want to add a lil to your electrical, just to be on the safe side. Main reason i say that, is that while 12.5 is acceptable, you could easily still drop down in to the 11's when idleing, or under heavy play. a second batt should be able to keep you in the 13's while driving

I cant hardly turn it up while idling, maybe 30 volume before I see massive voltage drops.

But I was told on here by another member not to use ANY bass boost, and right now Im currently using alot........... so Im going to turn all the bass boost off, and reset my gains using a DMM. He said it may be clipping, causing even more voltage drop. We'll see, but Im pretty sure I need a second battery.

Wish I could just add a battery to what I got...

Edit- So I turned all bass boosts off. Adjusted gain to 33V which should be something like 1625W (.67 resistance if I wired it right) and now Im having no more voltage drops than I did before I upgraded. 14V down to 13.6. Bad news is, its uber quiet compared to how it was. But it does sound much cleaner, I just miss the loud //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif