Bimmerfest - BMW Forums

Bimmerfest - BMW Forums (
-   E39 (1997 - 2003) (
-   -   Cool to run subs on stock battery? (

iceman4169 01-08-2013 03:13 AM

Cool to run subs on stock battery?
Hey everyone im planning on running 4 12 inch subs in my trunk. Im running 2 1500 watt amps to power this and a very good capacitor. Can the stock battery handle this kind of power? 99 540i

edjack 01-08-2013 09:49 AM

All depends on pattern of usage. You'll need to ask your ricer friends what they do. The group 49 battery is rated 8-900 CCAs. Bear in mind, it's the alternator that powers the car when running. It may not be strong enough at stoplights to power the amps.

If you run curbside for any length of time on the stock battery, you may be hurting.

Consider seeing an otologist.

iceman4169 01-08-2013 10:57 AM

No ricer friends here. I just make show cars thought itd be a sick idea for a 540 to be one. Should probably just go big on it. Stronger alternator and optima battery. These cars have lots of sensors though. Possibility of too much power? Btw thank you for your response.

Stone Roots 01-08-2013 11:47 AM

I did some work for a friend of mine who owns a auto sound store here in North County - so he traded stereo for work. Part of the trade was a JL w713.5 powered by a 1000/1 JL amp. I installed myself since they didnt have time for it - i dont NEED that much sub - but when its turned up its a HUGE draw and all the lights (-minus headlights) pulse to the draw.

So if your going beyond that - you will need to upgrade your alternator - possibly add extra batteries. I might upgrade the alternator in future - but as it is sub is just supplemental at this point - even though it can be a neighborhood waker when turned up...:bigpimp:

mpower997 01-08-2013 12:13 PM

O.P- try running a red top optima and a large 3+farad cap, should be good.

iceman4169 01-08-2013 01:08 PM

Im running a lanzar vcap 50 farad. Possibly good?

DennisCooper! 01-08-2013 02:33 PM


Which actual amplifiers are you running? if they are a 'true' 1500 W RMS each, then you absolutely have to uprate your power capabilities as they'd be drawing MASSIVE amounts of current. If they're '1500W' peak, then if they're a cheap budget brand, it's likely they're giving out perhaps 500-600 W RMS. You'd still need to uprate your power though as you will have other amplifiers for the mid range and treble with their own current requirements. If you have high quality brand amplifiers, then they'll have much more efficient and better internal power supplies and you won't really need to use a capacitor. If you look at competition level installs and excellent amateur level ones using high quality products, hardly any use a capacitor.

You need to plan your install carefully if you wish to run high RMS power outputs - have you considered all the 'true' power requirements, proper fusing and protection, correct grade wiring and the large amounts of sound deadening material you'll need? that's all on top of needing a very solid and strong enclosure for the subs, planning the rest of the system as well.

Cheers, Dennis!

iceman4169 01-08-2013 05:06 PM

Dennis thank you for your reply, I've worked on show cars for awhile was just wondering about the battery but everything youve said is absolutely correct! Im running interfire. Theyre 1500 but im almost sure thats not the rms being put out thats why i feel its safe. Im going to make the box built to specs of the subs and have the port running through the back seat arm rest. Again thank you very much for your reply Dennis much appreciated and exactly the answer I was looking for. Take care

AnotherGeezer 01-09-2013 07:23 AM

4 12's?

Can you say...overkill?

iceman4169 01-09-2013 11:09 AM

Yea makin it a show car thats the overall goal boss

speedninja 01-09-2013 06:10 PM

buy another battery your stock is not going to survive

iceman4169 01-09-2013 07:06 PM

what kind? ive used optima yellow top but someone told me red is better? opinions?

guysimmons89 01-09-2013 10:45 PM

Ya your probably gonna want a separate battery, as well as a new trunk lid and hearing aids.

iceman4169 01-09-2013 10:47 PM

Been there dude trust me. Used to do competitions. But was just wondering how much the stock one on the 540 can handle. Brings me back sometimes id be tuning it in the trunk and i cant see straight things blowing sound into my head lol

ill540i 01-09-2013 11:18 PM

I had an l7 with alpine m100 amp in my trunk with the stock battery and it lasted for about 5 months

Sent from my MB502 using Bimmer App

All times are GMT -7. The time now is 10:46 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
© 2001-2015 performanceIX, Inc. All Rights Reserved .: guidelines .:. privacy .:. terms