melonhead Posted April 20, 2010 Author Report Share Posted April 20, 2010 So I've been reading comments from a few threads below regarding how to install the 2nd battery and I just want to confirm this. I need to run a cable from the positive on the front battery to the positive on the 2nd battery? Then I need to run the negative from the front battery to the negative on the 2nd battery OR I can just ground the 2nd battery in the back of the car? Then I should fuse it on both ends near the front and back batteries? Quote Link to comment Share on other sites More sharing options...
dmanson Posted April 21, 2010 Report Share Posted April 21, 2010 So I've been reading comments from a few threads below regarding how to install the 2nd battery and I just want to confirm this. I need to run a cable from the positive on the front battery to the positive on the 2nd battery? Then I need to run the negative from the front battery to the negative on the 2nd battery OR I can just ground the 2nd battery in the back of the car? Then I should fuse it on both ends near the front and back batteries? some people run a negative to the back and then some just ground the 2nd battery to the chassis .... then some run negative to the 2nd battery and ground it to the chassis for overkill. either will work. i have a run of positive and negative from the 1st to 2nd battery, i sit at 15.5 with my setup, mimimum voltage drop. Quote 2-DC 15XLM2 D.7s 1-DC 5K amp (1) XS Power D6500(UNDERHOOD) and (1) XS3000(REAR) 3 runs 1/0ga for power and 2 runs of 1/0ga for negative. (2)-RFT165s components, ...... 4 separate 1 inch tweetersRF T600-2(fronts) Punch 450.4(rear) Audiocontrol 3.1. DC power 260amp alternator w/MLA Module Link to comment Share on other sites More sharing options...
melonhead Posted April 21, 2010 Author Report Share Posted April 21, 2010 some people run a negative to the back and then some just ground the 2nd battery to the chassis .... then some run negative to the 2nd battery and ground it to the chassis for overkill. either will work. i have a run of positive and negative from the 1st to 2nd battery, i sit at 15.5 with my setup, mimimum voltage drop. Ok great. I know I need to run my amps to the back battery and my next question is this. Is the front battery going to be used strictly for the car and inside the car like A/C, heater, etc.? And will the amps be strictly running off the back battery by itself? How is the load spread across both batteries? Quote Link to comment Share on other sites More sharing options...
BrAdAsS Posted April 21, 2010 Report Share Posted April 21, 2010 The alternator and battery could be upgraded, but, your still not addressing the problem directly. The problem is the bass hits, drops the voltage and lights dim. Another option is to see what the voltage is dropping to and use a dc to dc converter to run the headlights, rated to work from 9v to 15v. This will counter the bass hit-voltage drop atleast for the lights so if it hits 10v on a bass note, it's still making the same light as it does at 14v. I've noticed my HID's don't dim, so I pinched that idea from them. No converter is 100% efficient so there is a small overhead trade-off. Quote 2000 VX Holden Commodore V6 Optima D34M The Big 3 / 4ga Hot Earth 108sqft Dynamat Extreme 120A Alt Alpine CDA-9815 +/- 0 gauge run 2F Aerpro cap F/R: Peerless Resolution 6" 2-way / Alpine MRP-F600 Subs: 2x 12" Kenwood KFC-W3011 in moulded f/glass 1cuft boxes / Alpine MRD-M501 Link to comment Share on other sites More sharing options...
melonhead Posted April 23, 2010 Author Report Share Posted April 23, 2010 The alternator and battery could be upgraded, but, your still not addressing the problem directly. The problem is the bass hits, drops the voltage and lights dim. Another option is to see what the voltage is dropping to and use a dc to dc converter to run the headlights, rated to work from 9v to 15v. This will counter the bass hit-voltage drop atleast for the lights so if it hits 10v on a bass note, it's still making the same light as it does at 14v. I've noticed my HID's don't dim, so I pinched that idea from them. No converter is 100% efficient so there is a small overhead trade-off. If I am having a voltage drop when the bass hits, wouldn't the 2nd battery help with that? Also, what size fuses would I need on both ends of the cable from the front to back battery? Quote Link to comment Share on other sites More sharing options...
BrAdAsS Posted April 24, 2010 Report Share Posted April 24, 2010 Battery voltage is say 12.6v and Alternator voltage is say 14.4v. The dimming is noticeable as the alternator output is exceeded by the additional load, so the draw defaults to the battery voltage which is always lower. Another battery will help, but it still will attempt to do the same thing when the alternator output is exceeded. The fuses should be rated to handle the maximum draw/charge going through the cable to match your setup/gear.. Quote 2000 VX Holden Commodore V6 Optima D34M The Big 3 / 4ga Hot Earth 108sqft Dynamat Extreme 120A Alt Alpine CDA-9815 +/- 0 gauge run 2F Aerpro cap F/R: Peerless Resolution 6" 2-way / Alpine MRP-F600 Subs: 2x 12" Kenwood KFC-W3011 in moulded f/glass 1cuft boxes / Alpine MRD-M501 Link to comment Share on other sites More sharing options...
splzx3 Posted April 24, 2010 Report Share Posted April 24, 2010 (edited) bradass ok wut about the people that have 2 have a 40-8 0 amp fuse for the class there in? u need 2 get some info be4 u help... op i run a 2400 mono and a 200.4 (50 rms a 4 ohms) amp and i have a oem 110 amp alt and a yellow top in the hood and a bt-100 in the back and i dont drop under 13.5 i would get a big back battery and do a run (+ and -) of 1/0 from the front 2 the back battery then see if u want a alt yes and no u will need a fuse on both side (it ur call about that) but u will need one fuse (300 amps if it is 1/0 and 150 if it is 4g) sorry for all the info Edited April 24, 2010 by 01zx3 Quote ________________________________________________________________________ deepsilencer, on 22 Aug 2011 - 17:32, said: splzx3, on 22 Aug 2011 - 17:27, said: i had my fun on one of his videos...till he blocked me then i got my mother into it lol after her he closed the comments xD lol your mom is a G! WTF, I never thought I'd have a conversation about cross dressers and trans-genders on a car audio forum. Link to comment Share on other sites More sharing options...
BrAdAsS Posted April 25, 2010 Report Share Posted April 25, 2010 bradass ok wut about the people that have 2 have a 40-8 0 amp fuse for the class there in? u need 2 get some info be4 u help... op i run a 2400 mono and a 200.4 (50 rms a 4 ohms) amp and i have a oem 110 amp alt and a yellow top in the hood and a bt-100 in the back and i dont drop under 13.5 01zx3 I didn't want to post, but; what about those people? I don't compete, did you mean the OP is competing? My bad, I missed the OP saying that when I read through all the posts.. Im still wondering what practical information for the OP your message had. If you have 2x batteries, that will help maintain the voltage under load car off, but, still, as soon as you exceed the capacity of your alternator completely it will drop to the uncharged battery's voltage. Does your vehicle already have a dc:dc converter for the headlights? Some vehicles have one from factory. By the sounds you still have the same problem, but, your alternator is able to supply enough to cover the majority of extra load from your stereo before it reverts to battery voltage - hence the voltage drop. Looking at your sig, you have one alpine type r sub powered by a 2400wrms amp... Do you compete with that do you? Upgrading to a bigger alternator before the 2nd battery would have more of an effect on dimming by maintaining the higher voltage when the car is running. If the car lights dim when the engine is off then the alternator is not the cause. A 2nd battery would help more then. I wouldn't consider it as safe to let 300A flow through a cable that only needs to supply 150A. The whole point to matching the fuse size to the equipment. OP I have a 4x100wrms and a 1x550wrms Alpine combo with a D34M bluetop and police-spec 120A alternator, all 0 gauge. I myself use 80A and 120A resetable circuit breakers at the amps and a 200A fuse at the battery. My vehicle consumes a good portion of the alternators output to run which doesn't leave the stereo as much as it needs, hence why my lights dim. Quote 2000 VX Holden Commodore V6 Optima D34M The Big 3 / 4ga Hot Earth 108sqft Dynamat Extreme 120A Alt Alpine CDA-9815 +/- 0 gauge run 2F Aerpro cap F/R: Peerless Resolution 6" 2-way / Alpine MRP-F600 Subs: 2x 12" Kenwood KFC-W3011 in moulded f/glass 1cuft boxes / Alpine MRD-M501 Link to comment Share on other sites More sharing options...
Ray Posted April 25, 2010 Report Share Posted April 25, 2010 HID'S are the only thing that will "FIX" your problem. Quote 2008 California state record holder 157.2 Bassrace2009 California state record holder 157.0 BassraceRollin 50's 158.7db2009 King of Cali Bassrace2009 USACi score 160.5 @ 42hz Link to comment Share on other sites More sharing options...
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