Acceptable voltage loss

[mast240 10+ year member]

Nah I'm all set if I didnt post there would be so much missinformation around this board. and yeah that 150a isn't doing what a normal 150a is doing for power but it's still better than a stock 90a. Why do you think I told him to give it RPMS while idling? Funny how you call me an idiot when I could show you this setup running daily lol.

your the one giving out misinformation... please, just stop

 

[Fi_ 10+ year member]

your the one giving out misinformation... please, just stop

Could you please explain what I am missinformed about?...

 

[KTMrida4life 10+ year member]

OP 150a alt isn't really considered ho by many people. With that said big 3 a better battery than a duralast gold. Also look into another small battery. Low ohm loads like that pull some power.

I know that, usually their upwards of 200A. Well I first specified it was a 150A alt and people assumed stock. Its not. Its the highest rated alt I can find for my tiny car.. its a 95 Nissan 240sx. 2.4L.

I will do the big 3. I wouldnt mind a second battery, what bothers me is that I just bought this duralast gold battery less than 6 months ago. It still has 2.5 years of warranty on it. To not use it would be stupid. From what I've read, it's not recommended to hook up an AGM battery in my trunk to an acid battery like I have.

I guess I'll just do the big 3, hook everything up and pray. Ill keep my volt meter in, and start with the volume way low to see what kind of voltage drops Im getting. I'll set the amp with a DMM to 1500W. If I drop down to say 12.5V, is that OK? At that point, are headlights/interior lights dimming? Ive been told to not go below 12V as thats when you fry things.

 

[mast240 10+ year member]

telling someone it's safe to run that size amp, on that impedance, on that electrical... dude, just no... not safe at all... a higher impedance, maybe... but, just cuz your "friend did it with no problem"... that in NO way means its adviseable, or smart.

please, stick around a lil, and learn from some of the more veteran members here... but stop giving out bad information

 

[Fi_ 10+ year member]

telling someone it's safe to run that size amp, on that impedance, on that electrical... dude, just no... not safe at all... a higher impedance, maybe... but, just cuz your "friend did it with no problem"... that in NO way means its adviseable, or smart.
please, stick around a lil, and learn from some of the more veteran members here... but stop giving out bad information

I just don't agree... Sorry. I will stick around and learn but I honestly think this guy will be ok. and 12.5v MAXIMUM drop if it goes any lower than 12 turn it down and start upping your electrical.

 

[mast240 10+ year member]

I know that, usually their upwards of 200A. Well I first specified it was a 150A alt and people assumed stock. Its not. Its the highest rated alt I can find for my tiny car.. its a 95 Nissan 240sx. 2.4L.
I will do the big 3. I wouldnt mind a second battery, what bothers me is that I just bought this duralast gold battery less than 6 months ago. It still has 2.5 years of warranty on it. To not use it would be stupid. From what I've read, it's not recommended to hook up an AGM battery in my trunk to an acid battery like I have.

I guess I'll just do the big 3, hook everything up and pray. Ill keep my volt meter in, and start with the volume way low to see what kind of voltage drops Im getting. I'll set the amp with a DMM to 1500W. If I drop down to say 12.5V, is that OK? At that point, are headlights/interior lights dimming? Ive been told to not go below 12V as thats when you fry things.

the main thing you want to stay away from is running a larger AH AGM batt in the back than your start batt... but even then, it wont do much. where you'll run into the most problem is if you're running a HUGE difference in AH between the 2. You can pick up a smaller AGM for the back, and it wont affect your front batt, and it will help ALOT to keep your voltage up, especially under full tilt.

 

[KTMrida4life 10+ year member]

the main thing you want to stay away from is running a larger AH AGM batt in the back than your start batt... but even then, it wont do much. where you'll run into the most problem is if you're running a HUGE difference in AH between the 2. You can pick up a smaller AGM for the back, and it wont affect your front batt, and it will help ALOT to keep your voltage up, especially under full tilt.

Hmm..

I'll get the model number off my battery tomorrow and see what its rated for. I cant remember the CCA..

How would I know how many AH my current battery is if its only ratted for CCA and cranking amps (afaik)?

 

[mast240 10+ year member]

get the model number off of it, and you can look it up. Sometimes it's on the data stamp, but not always

 

[KTMrida4life 10+ year member]

get the model number off of it, and you can look it up. Sometimes it's on the data stamp, but not always

Just went out and looked. Duralast 24-DLG. 750 CCA.. all I can find on it :S

 

[mast240 10+ year member]

its a 130 AH

 

[KTMrida4life 10+ year member]

its a 130 AH

Well I read on here THREAD that RC/2= aH, or it gets you close anyway.

Is that wrong? That would mean my battery is more along the lines of a 75 ah battery.

Im still reading more and more about how your not supposed to mix wet cell and AGM batteries..

Like I said, I'll see what kind of voltage drop Im getting tomorrow or whenever I hook this all up, and go from there. If its bad, I'll get 2 batteries and sell mine somehow.

 

[mast240 10+ year member]

your right.. i looked at the msds on it wrong... good catch... it should be in between 70-75

 

[KTMrida4life 10+ year member]

your right.. i looked at the msds on it wrong... good catch... it should be in between 70-75

Ok good. One more thing I just want to clarify. One would assume the voltage drop would get worse as the volume is turned up higher, is that correct?

 

[mast240 10+ year member]

yea, thats what i meant by full tilt.... when you set your gains, you're going to find what volume on your HU sends a clipped signal, and then one setting below that will be your max... thats full tilt. as you turn your source up (volume), your amp will pull more amperage.

short answer, yes, lol

 

[KTMrida4life 10+ year member]

yea, thats what i meant by full tilt.... when you set your gains, you're going to find what volume on your HU sends a clipped signal, and then one setting below that will be your max... thats full tilt. as you turn your source up (volume), your amp will pull more amperage.
short answer, yes, lol

Not 100% sure at what volume my headunit clips at, but Im pretty sure its either 42 or 43. So I set the gains at 40 and just never go higher than that.

Sometimes I swear it sounds like my speakers are distorting (not subs), then I realize its just my door panels vibrating... really need to put the AT I bought in the doors.

But I CANT because SOMEONEEEE decided to hit my passenger side door + rear quarter panel and f it all up, so its going to a body shop soon for no telling how long and maybe even painted while its there. If Im going to wait I may as well have it painted.

If you care, go search on google images "midnight purple 240sx"

I