WHat do you run...

nor_cal_01super 07-19-2006, 3:39 PM

I am discovering that the stock Alternator on my boat is not sufficient for my after market stereo and dual batteries.
What have you all done to solve this problem?
I am running 2 amps, total of 950 watts and my fues' total 80amps with dual blue top optima batts....
Thanks in advance....

E$

(super_air) · (super_air) **Join Date: Jun 2005** 07-19-2006, 3:43 PM

With 950 total watts your stock alternator and two blue tops should be plenty. It sounds like you are not starting out with a full charge on your batteries.

I am running a 140 amp alternator with 8 blue tops and a built in charger on my 01 SAN.

walt 07-19-2006, 3:51 PM

I'm running,
1-500 watt 1 channel
1-300 watt 2 channel
1-200 watt four channel

It's all stock but two batteries and it's working fine so far.

(jaybird) · (jaybird) **Join Date: May 2006** 07-19-2006, 4:00 PM

how many amps is your stock alternator???
JJ

(iagainsti) · (iagainsti) **Join Date: Apr 2004** 07-19-2006, 4:09 PM

That system should not be killing your batteries unless your playing for really long periods with the boat off. Buy a 3 stage charger and top off the batteries at night.

nor_cal_01super 07-19-2006, 4:55 PM

Thank you all for the replies.
I believe the stock ALt is only 40 maybe 60amps, I have an 01 SAN with the GT-40 by PCM.
I put a volt meter on my batt cables and its only hitting 12.95 with a good amount of throttle. SO I think its just slowly fading out cause it can not keep up even with the motor on with the amount of amps my stereo is pulling.
I am looking to see what my options are in getting closer to 100amps in a marine application for a ford motor, I think that should be sufficient for my set up dont you all think???

nor_cal_01super 07-19-2006, 4:57 PM

Oh, and I had to ask what CAR is running off of 8 BLUE TOPS!!! That also must help to throw a FATTY WAKE behind your Super!!!

(liquidmx) · (liquidmx) **Join Date: Jun 2005** 07-19-2006, 5:01 PM

I am having a similar problem but its more related to ballast pumps. Running 4-5 pumps at a time results in a significant drop on the voltmeter. Can anyone give me a link and estimate on a high output alternator for a 2000 malibu wakesetter with the monsoon motor?

Thanks.

nor_cal_01super 07-19-2006, 5:25 PM

KG,
Thanks for the reply,
I have a 3 stage but as i mentioned above my actual alt is only throwing 12.95v out with a load on the motor, so even if I top mine off before I head out I have the possibility of not being able to keep them charged.
Prob sounds like I am answering my own question, but I am really curious as to the options out there with after market alt for my GT-40 motor...

(phatboypimp) · (phatboypimp) **Join Date: Apr 2005** 07-19-2006, 6:39 PM

I took my stock 70amp alternator and had it rebuilt to 130amp for about $200. I have six blue tops (five for stereo and one for ignition) and it will bring the batteries up from 11.0 to the high 12's while wakeboarding in between drinking sessions.

(mikeski) · (mikeski) **Join Date: Aug 2003** 07-19-2006, 8:55 PM

My system is just south of 2500 watts, no lights (except LEDs), 100 amp alternator, two golf cart batteries, works for me.

Here is a little Excel spreadsheet that can calculate your needs, it calcs pretty close to reality for my boat:

Upload
Alternator calcs.xls (17.4 k)

Download it and open it in Excel then just fill in the blanks as shown.

(acurtis_ttu) · (acurtis_ttu) **Join Date: May 2004** 07-20-2006, 6:31 AM

my system is close to the size of mikeski, but with the addition of 3 towre lights, same battereis, same size alt. The key for me is keeping my battereies fully charged when not in use. When I run my stereo (high volume) and lights my alt cannot keep up. But that is for short durations only.

(super_air) · (super_air) **Join Date: Jun 2005** 07-20-2006, 8:36 AM

E Money- I am running 5200 watts of orion amps,2-12w7's,10 speakers on the tower and four in the hull. Seven batteries are for the stereo and one for the engine.

(flux) · (flux) **Join Date: Jun 2003** 07-20-2006, 8:53 AM

Does anyone think 12.95 Volts from the alternator is a bit low??

I am thinking you should be seeing 14 volts +/- 0.5 volts from your alternator.

(acurtis_ttu) · (acurtis_ttu) **Join Date: May 2004** 07-20-2006, 9:11 AM

yes, it's a little on the low side, but unless your seeing that on a voltmeter, it's proabbly not accurate. My dash voltmeter will read 13.3 or so and with the instrument it's reading 14.2-14.5. Also, as the amp draw increases the voltage will drop. typical 100 amps alternators under full load will throw around 13.3-13.5 volts, usually only at full charge will you see the full 14.2-14.5

(clayton191) · (clayton191) **Join Date: Apr 2006** 07-20-2006, 9:39 AM

So how do you calculate wattage for saying how big your stereo is?

Example. I have two 10 subs rated at 375W max. I have two wetsound pro 80s at 225W RMS. I have four cabin speakers at 45W.

Ampwise, I have a 600x2 and 450x4 Rockford Fosgates.

I'm just trying to figure out how much wattage I have :-)

(acurtis_ttu) · (acurtis_ttu) **Join Date: May 2004** 07-20-2006, 9:59 AM

the total RMS wattage that your amplifiers produce.