E23 735i Charge System... - United Bimmer Community

**QcMarque** · 11-02-2006, 11:40 PM

Alrihty... so I'm going to be installing my stereo system here soon and I know I'll need additional power to keep the system charged and not kill the battery. What's the best way to go about this?

*keep in mind I'm pulling about:
200watts constant per channel for component speakers - 4ch
800-1200watts constant for subs
a 1.5 farad cap

1) Should I get a bigger cap?
2) Alternator: I haven't been able to find an oversized alternator... so I plan on probably mounting a 2nd alternator.
2a) with that should I mount a 2nd battery (basically give the sound system it's on power & charging supply)... or should I have 2 alternators charging 1 battery?
3)Component replacement... before I tear into existing the speaker system, does anyone know if what's there is common ground, or does each speaker have its own ground?

Every bit of help I can get would be wonderful... I'd like to have as few surprises as possible when I start pulling panels and wires. If I have to I'll replace all the speaker wire with some nice 14awg and basically isolate the system.

Lastly... I'm in need of a working power antenna. Anyone have one they're willing to part with?

Thanks a million everyone!

**Numark318i** · 11-03-2006, 12:30 AM

Quote:

Originally Posted by QcMarque

Alrihty... so I'm going to be installing my stereo system here soon and I know I'll need additional power to keep the system charged and not kill the battery. What's the best way to go about this?

*keep in mind I'm pulling about:
200watts constant per channel for component speakers - 4ch
800-1200watts constant for subs
a 1.5 farad cap

1) Should I get a bigger cap?
2) Alternator: I haven't been able to find an oversized alternator... so I plan on probably mounting a 2nd alternator.
2a) with that should I mount a 2nd battery (basically give the sound system it's on power & charging supply)... or should I have 2 alternators charging 1 battery?
3)Component replacement... before I tear into existing the speaker system, does anyone know if what's there is common ground, or does each speaker have its own ground?

Every bit of help I can get would be wonderful... I'd like to have as few surprises as possible when I start pulling panels and wires. If I have to I'll replace all the speaker wire with some nice 14awg and basically isolate the system.

Lastly... I'm in need of a working power antenna. Anyone have one they're willing to part with?

Thanks a million everyone!

Pm Harry(Komodo) about the alternator. He had a beefed up one on his 328 a while back. Im sure he knows more about it.

**QcMarque** · 11-03-2006, 12:38 AM

Thanks!

This has been the only board I've found where people actually reply to posts. Quite refreshing.

**c1apton** · 11-03-2006, 03:37 AM

A dual battery system would be more feasible than two alternators. You can use a system similar to marine applications/race cars - using a deep cycle battery for your secondary battery.

**QcMarque** · 11-03-2006, 04:14 AM

Would you not then need a more powerful alternator to keep both batteries properly charged (especially during the more bass intensive sessions)?

**c1apton** · 11-03-2006, 07:59 AM

One alternator would be more than adequate (provided it's a fairly high output as the majority of BMW alternators are) The marine dual battery systems use one battery for starting and normal ignition functions and the deep cycle handles all the excessive accessories and the duties when the motor is not running. They come with an automatic switcher that sends current to one or the other or both batteries (when needed) So in your case you'ld hook up all your audio gear to the aux or secondary battery. No big deal and you avoid the headache of trying to fabricate a second charging system.

**RSF5** · 11-03-2006, 10:10 AM

Yeah a second battery would be the best way to go rather than messing with a new alternator. It will give you the power you need while the car is running, you might want to also think about a 3 farad cap. or around that.

**QcMarque** · 11-03-2006, 04:20 PM

Quote:

Originally Posted by c1apton

One alternator would be more than adequate (provided it's a fairly high output as the majority of BMW alternators are) The marine dual battery systems use one battery for starting and normal ignition functions and the deep cycle handles all the excessive accessories and the duties when the motor is not running. They come with an automatic switcher that sends current to one or the other or both batteries (when needed) So in your case you'ld hook up all your audio gear to the aux or secondary battery. No big deal and you avoid the headache of trying to fabricate a second charging system.

Alrighty... so make sure I've got the 90amp alternator, and a deep cycle battery to run the sound system off of. Think I should replace the existing battery with a deep cycle as well?

**c1apton** · 11-03-2006, 05:05 PM

I'd keep the stock battery for the stock equipment, the deep cycle for the "add ons". Also get an auto-switcher for a dual battery set up - do NOT try to just put cables between batteries (some folks try to cut corners and it turns out to be a costly mistake) You can get these switchers from marine, camping suppliers & some parts stores.

**QcMarque** · 11-03-2006, 05:43 PM

excellent... once everything setup I'll post an update.

Thanks everyone!

**QcMarque** · 11-03-2006, 06:41 PM

Hmm... so I figured I'd start with the rear deck speakers, and know what? I have no idea how to get the blasted things out

From the trunk side they're sealed, and there's nothing on the deck that shows signs of a pry spot or anything to remove the black cover to get to the speakers themselves. Anyone know how to get to them so I can put me PG's in there?

**QcMarque** · 11-15-2006, 12:47 AM

Wow... I feel stupid... got the rear deck speakers out, 'cabinets' altered and speakers mounted (Phoenix Gold Xenon all the way around, as well as subs and amps)

Just have to modify the rear deck itself to fit the larger speakers, alter the original grille to cover mounting screws, and run wiring for the amp... next comes the front sets (I think these'll be the hard ones) and the deck.

Woohoo!