whats up guys. so i need a second battery in my car for all the current im running with my audio.

has anyone mounted a battery UNDERNEATH (have seen a couple of trucks have this done) the car or maybe even a second one under the hood?

where do most of you put your battery?

i already have about 200 lbs in the trunk from my box/sub set up. i dont want to add too much more weight back there. especially cus when i have passengars it drops too low (scrapes) easily. also would like to retain trunk space.

i was thinking maybe under neath the carpet in the spare tire well, but i also want to be able to pull out the spare tire easily if needed.

suggestions?

 

Can you put up pictures of your current trunk setup? A 30 lb battery isn't going to add much more weight if you already have all that equipment, also what makes you think you need an extra battery? Do you have a Capacitor or maybe you need to upgrade your alternator. What are the issues you're having with your entertainment system?

 

Caps are crap, high output alternator is too expensive (the real ones that is). Just get one of these:



Only 14lbs H-6.5"/W-7"/D-3" and you can probably fit it under your hood.

 

however, I'm currently working on a custom bracket for a second alternator if you're interested make a bracket and add ANY alternator you want Doesnt have to be high dollar high output either since it will be added to your current one.

 

yeah il post some pics. currently (as mr jokster below knows) i'm working on a whole new set up and thinking about getting new amps along with new speakers all around. speakers should be ordered in the next week or so.

the trunk however currently consists of one 12" RE Audio MX. This is only TEMPORARY, while i put in a 4th order box that is ported through the rear deck (to get bass into the cabin and avoid trunk rattle). I usually have a 4th order ported through the rear deck as my daily set up, but since im in the process of constructing everything- i have the RE Audio MX in a ported box as a temp solution.

here are some pics of set up:

This is my temporary 12" RE MX. i dont have any pics of it. but i have a very short and low quality vid i shot a while back. you can see how its set up:



and here are the pics of what the 4th order in the trunk usually looks like (new one wont look much different since itl be sealed off and ported through deck in the same manner. ill probably just throw an Ascendant Audio sticker instead of RE Audio):










This isnt the exact amp set up i have anymore. as i mentioned. i have a sundown and arc audio running everything now. but its the same layout in which the amps are mounted behind the seats inside the trunk and are hidden by the box once it is.







As for my electrical. I already have a H/O Alternator- DC XP 270 model. it should be cranking out about 270 amps. About 100-120 at idle. Full amperage by 2500 rpm i beliver. My voltage is decent- however i get extreme dimming still. I've asked around a couple of shops and friends and everyone says i need the extra battery in the car to help hold up with all the demand.
I also have a capacitor btw... Mr jokster is right- theyre garbage. they dont do anything and a couple of shops have even told me it might even be putting a strain on the electrical. i already installed it and it was a ***** to do so because of the particular place/angle where i mounted it, so that baby is staying in there until (IF) a new battery goes in.

Pretty much the issues im having with it all is that despite having a 270 amp alt AND a Kinetik 2400 battery (which btw is close to 70 pounds- twice what you had estimated lol) i am still getting some major dimming. At full tilt my voltage can get as low as 12.3 volts. so unless the battery and alternator are both bad- then it seems my electrical needs some help in keeping up with all the demand im constantly putting on it. i blast my system 24/7 whenever im in my car. rarely will it be low or off. im pushing two amps. a sundown 1500 and ad arc at 80 watts x4

thanks for the tip jokster. il definitely look into it. im hoping a small battery like this can do the job and that i wont have to go out and buy another huge one. i dont mind the purchase of it- but its the mounting of it and finding a spot to put it that i dont want to struggle with and have to add on to the car.

hahaha thats awesome man! ive seen these in trucks and and suvs and i thought it would be bad *** to have one in our gs' so we can throw in another alt and get some extra power. i currently have a DC H/O alternator that i bought about a year and a half ago. Its supposed to be 270 amps- and yeah it did cost quite a bit. was just under $600 bucks. Definitely brought my voltage up as soon as it was installed. But i sitll do have my stock alternator saved and i could throw that in there. =)


here are some more pics of the electrical and h/o DC alt to keep things interesting. i mightve posted some of these in a thread in the past though:

Old Kinetik 1800 battery (its a 2400 now in that exact spot but dont have a pic it updated)







Some pics of alt:

Installed:



Before installed when i first got it:

 

In the MX vid you can see where my cap is mounted and you can also hear the terrible sound rattling that i try to avoid with a 4th order.

quick update. ive been looking under neath the carage of the car and it doesnt look like there are any spots or gaps where i could mount a battery underneath =(
i was really hoping that could work out so that i would avoid putting anything inside the car. aside from the weight- i also want to save room.

did some searching on here also and i couldnt find much on this specific topic. the few things i did find- including a battery relocation diy; were all to the trunk in the wheel well. im going to see if i can fit the battery down there while still retaining easy access to the spare tire

 

That's a great box diagram, but I always went by the rule that if you face subs together they'll cancel each other out... In my old car I had two ports, one for each sub going into the cabin like that and it sounded great.

I would still find a place in the trunk for the battery, I would not mount anything else in the engine bay (Considering the additional alternator) and definitely not underneath the car.. Safety first, worse case scenario, god forbid you ever did get in an accident, you don't want that battery to explode.

 

What headunit are you using?
I had the same problem with my JL Sub and an audiovox DVD HU. (with the samme kintex battery you are using)
Now i have changed to a pioneer doubledin and no dimming anymore.
Problem was the 1,5V Preout signal of the Audiovox. The pioneer has 6 Volt so you have a much much better input for the amp to work with.

 

WOW thats a sick setup for the box. i never actually thought about having the box setup like that hahahah

how much that box run you?

 

Robert, the main problem is your amp man its too power hungry. I'm running WAY more power and my voltage drops to 10.5 and I barely get a slight dim, but my amps are much more efficiant.


Thats why you have to reverse the polarity, they only cancel each other out when wired out of phase. I've never heard of a rule about not facing subs together. Been doing car audio for over 10 years as well as owned a shop. There are MANY setups with woofers facing together.

 

4th order boxes are a btch to make, not many will make them because one slight miscalculation and your woofers are toast! not to mention box size is usually close to double of a standard ported box. 4th order box for two tens is about 70-80% of the GS's trunk space

 

haha yeah it would suck if it blew up. i went to a local shop and the guy showed me how he did a custom bracket for a guy with a truck and he mounted the battery underneath. i didnt think much of it at the time. in fact i didnt like it too much. the battery was super dirty and figured it could rust down there with weather and it could mess with the electrical if water got on it or something. but then when i was thinking about adding another battery this came to mind.

i would still love to do it based on my needs, but yes only if i could find a really good and safe way to do it. unfortunately regardless of everything, it doesnt look like the gs has any room for this down there.

as for the box- yeah i kinda had heard that too and for the most part i assumed it true. but the guy who designed it for me said it would work so i trusted him. and it did sound great and loud. that was my best set up yet actually. your two port set up sounds awesome. that would be ideal in my situation also, but i dont want to cut out any holes.or do permanent changes like that.
do you have any set up currently?

hmmm. great point Patrick. really good point. i hadnt thought about that at all.
actually however im not using a headunit. i have the stock nav. so im using a sound processor to get signal to the amps from the factory amp. its pretty much a fancy LOC- its the MTX RE-Q 5. maybe youve heard from it? its the only thing ive ever used since i put a system in. i ran a plain loc for a while actually but i had a much smaller demand. just two jl w3s and 700 watt amp.
and no dimming also. my dimming now is ridiculous.

haha thanks. i loved the idea when i saw it from a member on here too! i had been thinking about something like this and then i saw someone actually do it and i jumped on the idea. its awesome for better sound and to avoid that terrible rattling. i love it. like mr jokster said. its a lot more work and all but its very worth it.

i get the designs made online from guys over at car audio forum. but i build the boxes myself with the help of my dad. so it saves me a ton of money. designs are usually 20-30 box for a 4th order. and then building the box obviously just consists of the material (which i also save a lot on because my dad does construction so he has everything but MDF) and some hard work. i love this because it saves me so much money. i asked at one particular shop about prices for such a box before i went ahead and did all this and he quoted me at 500 dollars just to build the box. eefff that! it only costs me about $50 bucks to build a box if i do it myself. design+sheet of mdf and my dad has everything else ready. .. if you like it and plan getting something similar i would definitely recomend doing it yourself (if you think you know enough or know what you're doing)

yup. ive thought about this jokster. which is one rason why i said in the beginning of the thread that im really thinking about all knew amps. these sundownz seem to eat so much power so quickly! i start getting dimming and moderate sound levels where it just seems reidiculous to get dimming at. im really looking into getting something more efficient but geeze those amps are expensive!!! maybe if i can sell this sundown for a decent price i can afford something else. but the customer service from sundown is amazing. not only that but to get an amp that pushes this much power and have it be one of those higher end names will be extremely expensive. i have always thought that im not pushing enough power to get this kind of dimming with the electrical i have (big 3, h/o alt and 2400 batt) seems like a lot of electrical work and too much dimming/voltage drops. someone told me that our cars are very sensitive to voltage drops though. and that even slight drops or changes will cause it to dim because of the sensitivity. but i dont know how true this is. .. what amps are you running again (or did you switch)? im thinking about getting a jl 1200/1 for subs and 600/4 for full range. but i just dont know if the jl would push like the sundown does. and these ascedants im gona run LOVE power and getting loud.

i would like to figure this electrical thing out though or at least find an amp that pushes and doesnt go nuts on power eating.



yup they can be a *****. ive told jokster but no one else on here knows the hassles that my current design put on the guy designing this new box (not shown in this thread). and the building will be a *****. sooooo many cuts. but itl be worth it.

 

Haven't done my GS yet, but in my Volvo, I had three 12" subs in a sealed box facing the rear of the car and two ports in the rear deck. So this actually made my trunk into a band-pass box.

Well, what battery are you using now? Optima Yellow Top w/ 750 CCA ?
Are you running all 4 or 0 GA wiring? Are all your ground wires the same size?
I honestly think an extra battery would be overkill for your setup, I've done cars with bigger amps that don't even need an extra battery.

 

haha nice. any pics of that audio set up in the volvo? i had a box that was just ported through the rear deck and not sealed off, but in the gs its hard to avoid trunk rattle. which is why i swithced to 4th order.

im currently running a Kinetik 2400
All 0 gauge (big three done. and 0 gauge to the amp)
all grounds are 0 gauge.
AND i have a 270 amp h/o alt
i think an extra battery is overkill also, but there doesnt seem to be any other remedy. with my current set up. any ideas?

 

I guarantee the JL will blow it away. Have you see the bank of caps in that thing?



That thing powers itself. I was running 2 of those and another 1000watt JL 4-channel.

I have a friend with a repair shop and he hooked up one of those so called "4000watt" amps and when you watch how it sucks power, its UNBELIEVABLE! He hooked up the JL and the meter barley moved a mm (no joke) The cheaper amps are busy looking for juice to push power that it cant blow it out, good amp stays nicely charged on the inside to provide what it needs.

The science behind why you're dimming is because the amp is discharging the battery faster than the alt is putting out. If you fully charge the battery and play it [with car on], you will get no dim at all and it will slam! Give it a few minutes as the amp slowly discharges the battery, dimming will begin because the battery is completely drained and the amp is now basically running straight from the alternator and taking away from what the car needs. This is why smaller amps can push louder than some bigger ones because they come with a bank of caps to give what they need to run at 100%. Its like stacking boost in a car. You can give the engine 20 lbs of boost, but if it cant take it all, its not gonna use it all. Now give the engine 5lbs of boost and it will be MUCH faster and stronger than that of a 20lbs boost because the engine can handle 5lb much more efficient than the 20lbs.

Now if you give that Sundown EVERYthing it needs, then yea it will blow out lots of amps, but once you pay for all it needs, you could have bought the one good amp


I lost my train of thought lol, I'm done