Why does my battery really die?

I have a 12" MTX 9500 and an MTX 8100TC 2400 watt amp and a Mean green 200amp Alt in a Jeep Wrangler. Ive had Custom Sounds tell me my amp is bad but ive swapped amps and the same thing happens. If I have my gain really low, and let the radio do the rest of the bass, everything works fine. But when I put my gain up to really the way it should be, it all works until I turn my Jeep off and then when I try to turn it back on, the battery is almost dead. I know when its going to die next time I try to start it because right when I turn the vehicle off everythings instantly stops when usually my radio plays another 3 seconds before turning off. The speedometer lights up dull, the needles start bouncing everywhere and the starter tries to crank but stops. Other times, when I accelerate, the bass cuts out and when I come to a stop, its back on. But once again, only when I have my gain settings up for more bass from the amp. To get the vehicle started again, I have to disconnect the amp and the battery from the terminals and reconnect them to get it started again. Could this just mean my battery is going bad already? It is a stock battery now, and I did order an Optima Deep Cycle battery and it should arrive here soon, im hoping it will correct my problem. Any recommendations or suggestions or am I on the right path? Thanks.

Batteries wear out like everything else.  If you do routine maintenance- check the fluid level in the battery cells, keep the terminals clean, coat them with grease, check your cables/grounds for signs of wear, etc. it will prolong the life.  You said it's the factory battery- if you haven't kept up on the maintenance, and it's lasted 3-4 years or so, it's probably time for a replacement.

However, I'd get my charging system checked if I were you.  You said the bass cuts out sometimes when you accelerate.  This could mean that your alternator is not putting out what it should.  Regardless what it's rated at, have it checked.  Also, you should do the big 3 (read the sticky if you're unsure what this means).

Once the problem has been isolated/corrected, set the gain on your amp and leave it.  Do a search here if your unsure about this.

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My ex once told me I have a perfect face for radio.

Well you are probably draining your battery pretty quickly.  That can do some damage on a stock battery which isn't supposed to be constantly drained.  This could/most likely is damaging your battery which will reduce the time you can play music with the car off.  The the Optima should help.

The second thing that concerns me is how you are constantly changing your gain.  A gain isn't a volume control, and you should "set and forget it."  Once your find the right gain settings on your amplifier, then there is no other setting.  Do a search for "gain" in this forum for the proper technique on setting gains.  If you don't set it right, then you endanger your equipment.

P.S.  Why did the shop say your amplifier was bad?

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That's my opinion. Take it, leave it, or correct me.

geepherder...  You just beat me .

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That's my opinion. Take it, leave it, or correct me.

Thank you for the responses. The shop said it was a bad amp because whenever he turned the gain up, it would cut off. I tried turning the gain up when I got home and it didnt cut off. I also switched amps and it still worked fine. Im having to keep my gain less than half way and this amp needs a lot more gain to pound the kind of woofer im using. I will admit I have messed with the gain often because this woofer is suppose to pound really hard but its not sounding like my friends 10" Sony Explode only receiving like 800 watts to it. Wouldnt I start to lose power if the battery was bad or wouldnt the stereo start to die during use if it was going bad? Its not even a year old. and I can drive and use it as long as I want until I turn it off then its 99% dead. Then it can do a lot of weird things, my vehicle will flash lights, or turn hazzards on, and when I reconnected my negative to the bat, the vehicle started itself which I though was strange. Maybe the computer remembered I tried starting it when it was dead and finished its objective. Battery terminals are clean, but a little beat up. I may have the electrical checked out. It could be the new alternator, I put it in not to long ago but everything seems to stay charged. Could the amp connection be shocking my battery or can some kind of issue discharge my battery when I turn it off? I disconnect the wire from the battery to amp and everything works so far. Thanks again.

sounds like you need a new battery and need to read the gain turtoral at the begining of this page.    The gain is not a volume knob.....but it is a good way to blow up your expensive speaker by feeding distortion to it.

buy a new gel cell battery that will take the abuse your amp demands...like a kinetik or optima.

read the gain topic at the begining, and set it correctly or take it to a shop to set it correctly

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2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR
2007 USACI World Champion
2007 World Record
2006 USACI Finals 2nd Place

I got it checked out today. He said the battery comes out good and the alt must be charging the battery because nothing is dimming or turning off. The only thing I can guess is that during my bassing out, its killing the battery because it works fine if I dont. When I get my Optima installed, ill let you all know if it cleared up. Thanks again for the responses

Yeah I noticed a major drop in bass with the top off but with the hard top VS the soft top there really isnt that much of a drop in bass. Everyone keeps telling me not to use the gain much but without gain theres practically no bass at all. I have to turn up the radio a lot and its still not enough compared to the gain at 75% vs 25%. What am I suppose to do?

If that's a dual voice coil sub, disconnect one and see if your bass comes in strong.  What you describe could simply be an incorrectly wired sub.

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My ex once told me I have a perfect face for radio.

i feel for this guy, he is only messing with the gain because he is having issues. he is not lowering his gain to to silence his subs he is trying to test and set. but obviously he cant test and set if he is not getting possitive results. Pair corretly most people set there amps and 3/4 volume. he is saying he cant get that high or his battery goes dead..


now for info.

Upgrade ground from battery to chassis use like 0 guage or something. do the same from battery to alt and make sure you have a at least 0 guage wire going from battery to the amp.

check your ground on your amp as well make sure it is properly grounded to a clean area of metal and with your power i would say thru bolt it to the car. just because you have a 200 amp alt does not mean much. 200 amps could be its peak or when making it it could be a rounded up number from what the amp peaked out at. plus the 200 amps is only when driving at high rpm. when the motor is moving the fastest. but when it is at idle it may only thow out 100.

so for you there is a third factor there. check all your connections make sure they are sound and get a dry or gell cell battery.

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Jon
Installer/Help Technician
---coral springs florida---
mecp certification is not always needed. I have it and it has not helped me out at all. my experience out shines it.

Thats correct Jon. I went ahead and did a few upgrades and heres whats new.

MY UPDATE: I appreciate all the info that was sent. Heres I noticed my amps power light was dimming everytime there was bass also. I looked at my power and ground wire and the flip fuse box had an 80 amp switch while my amp requires 90 amps. I must have got so hot that it was melting the fuse box and it was sticking and wasnt fliping off. So I upgraded my wires first to 0/1 gauge and already my battery was lasting a lot longer and eventually didnt die on me anymore. I replaced my battery with a yellow top optima anyway and so far everything is running smooth. I still want to upgrade my terminals to 0 gauge as well but I have to save. I already want a 2nd Sub. Thanks again