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View Full Version : Do I Need More Juice?!


AZHAWK
05-18-2006, 02:33 AM
Dropped the boat off at the audio shop today. After discussing the planned set up, I was told that I should run four batteries. That seems like overkill to me... since most seem to be using the two Optima blue top set up. I have two batteries already just not Optimas.

Planned install:

Clarion Headunit with remote and cd changer.
2 JL 300-2 amps. (tower speakers rated 350 RMS x 2)
1 JL 300-4 amp. (boat speakers rated 60 RMS x 4)
1 JL 500-1 amp. (2 subs rated at 300 RMS each)

They are starting the install tomorrow and I need to let them know what do on the battery situation.
Suggestions Please!!!

JimN - I know that you will have some valuable info on this... I'd like to hear it. Thanks.

Foiler
05-18-2006, 05:26 AM
I found that multiple batteries for the most part are used while running the stereo when the boat is not running . I was ok until I added the juice robbing JL sub and amp to my existing amps and speakers.

With the stereo and blower on I sometimes would drop below my voltage limit and the system would cut out. I upgraded my 51amp alternator to a 135amp and have had no problems, I still only have one battery.

One battery wouldn't last very long with system up and the motor off but I've ran this setup for a 1 1/2 with no issues. A second battery would be a good ideal just to be on the safe side but I've had no issues.

If you're going to be sitting and playing your stereo with your boat not running for extended periods of time you'll definitely want more batteries if not you should be fine with two.
.
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ksmaristar91
05-18-2006, 08:26 AM
I would definitely suggest something in the lines, of a stiffening cap, or a multiple batteries, 4 souds a bit like overkill. The slash/ series JL amps do pull some current, but have a cool powersupply 2 good batteries and a cap should be suff. : on a side note, make sure they upgrade charging lead from the alternator. Foiler, where did you score the 135amp alt, would like to upgrade mine.

Foiler
05-18-2006, 09:26 AM
Autolectrics 408-559-3540 is where I bought my marine alternator. ($178.00 shipped)
I got an great deal on it, I think he has since raised his prices. I bet he's still a lot cheaper than others.
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zberger
05-18-2006, 10:11 AM
Here is the questions you need to answer for me..

How often or how much time will you spend with the boat motor OFF and using the stereo?

Don't bother with capacitors, IMO all they are is a drain on the system when they are dead.

What speakers are you going to be driving, and how many?

JimN
05-18-2006, 10:36 AM
AZHAWK- list the fuse sizes for the amps- the power output really is not a good determining factor for sizing the power supply requirements since nothing is 100% efficient. The draw is what's needed because output doesn't reflect the heat thrown off, which is still part of the equation. Also, the power ratings you listed with the tower speakers, subs, etc- is that the number of speakers and the amp's output or the speaker's power handling capacity?

AZHAWK
05-18-2006, 11:22 AM
JimN - Here are the fuse sizes:

The 300-2 and 300-4 series use 40amp fuses. (3x 40amp fuse)
The 500-1 uses a 50amp fuse. (1x 50amp fuse)

Yeah, thats the power ratings(speakers) and the number of speakers that are going to be used.

AZHAWK
05-18-2006, 11:32 AM
zberger - we do stop, throw the anchor out and chill with the tunes on. We never turn the music up that loud because this is usaully the time that the kids are napping. No more than an hour with the engine off, typically. We will mainly play the music at a louder volume while the engine is running and we are boarding etc.

Speaker set up:

Tower: Skylon Rubicon 350 series (1 pair)
Boat: Stock Clarion components series 1632 (2 pair)
Subs: The new 12" JL W3's (1 pair)

JimN
05-18-2006, 12:15 PM
Speaker ratings won't help to determine the power supply needs, just the amp's current draw.

So you're looking at 170A, worst case. Alternator/charging lead/ground need upgrading, add a couple of batteries and delete the cap. At this point, the cap would just be going along for the ride. You'll need to decide how loud you will play the system and for how long. That's what will really determine the needs. If you typically use 10% of the power, you should have no issues with heat (unless the amps are covered and can't breathe), distortion, headroom, etc.

I would really like the amp makers use/include a spec for dynamic headroom. They use it for home and pro gear, why not use it for mobile?

AZHAWK
05-18-2006, 01:18 PM
What should I tell them to use for the charging lead and ground upgrades? They may already be planning on this, I'll have to check. As far as the alternator goes, I'll have to look into upgrading this later when I get some time to research it more. Is the 51amp stock for my boat? ('03 X30 w/MCX) Sounds like I should get one like Foiler's 135amp. That should do the trick. Thanks again.

jmyers
05-18-2006, 01:26 PM
I am running 2 batteries! For: 1000 watt Concept amp to 4 concept 6x9's on the tower, 1 JL 400 watt amp to the 4 6.5's and 4 tweaters (stock) JL's, and (1) 400 watt JL amp for the "10 Sub JL! So far it is plenty and I have the PERKO switch to cange between batteries! Hop that helps! :wavey:

Diesel
05-18-2006, 01:35 PM
Speaker ratings won't help to determine the power supply needs, just the amp's current draw.

So you're looking at 170A, worst case. Alternator/charging lead/ground need upgrading, add a couple of batteries and delete the cap. At this point, the cap would just be going along for the ride. You'll need to decide how loud you will play the system and for how long. That's what will really determine the needs. If you typically use 10% of the power, you should have no issues with heat (unless the amps are covered and can't breathe), distortion, headroom, etc.

I would really like the amp makers use/include a spec for dynamic headroom. They use it for home and pro gear, why not use it for mobile?

FYI I can pull around 190 amps at full crank on my system and 2 blue tops last about 45 minutes to an hour.

Rockman
05-18-2006, 01:42 PM
zberger - we do stop, throw the anchor out and chill with the tunes on. We never turn the music up that loud because this is usaully the time that the kids are napping.

They won't be napping anymore once you get this system installed :D

zberger
05-18-2006, 02:11 PM
If you are only going to use it for an hour or so, even 2 at low volume.. I'd imagine adding 3 batteries would be ok. You would probably be safe with 2.. but for the extra money it might pay off if you are ever out on the water with some buddies and you decided to finish off a few cold ones, if you know what i mean.

To put it into perspective.. In the boat I did a stereo in.. we have a Kenwood 4 Channel amp that is rated with a 40 amp fuse, then we have an Orion 2 Channel sub amp that is rated at I think 60, We played that stereo for 3+ hours with the boat off on one single battery. It wasn't at full bore ALL the time, but for most of the time it was on pretty darn loud.

If I had your boat, I would probably get 2-3 batts, and upgrade the alternator to at least 100 amps, at a bare minimum.

So you are going to put a bridged 300/2 on each tower speaker.. those are gonna be LOUD.

zberger
05-18-2006, 02:14 PM
FYI I can pull around 190 amps at full crank on my system and 2 blue tops last about 45 minutes to an hour.

Sounds like someone needs 2 more batteries :D

Diesel
05-18-2006, 02:37 PM
Sounds like someone needs 2 more batteries :D

If I could find a place to put them I just might do it. :)

For me I really don't spend that much time at full crank when I am parked/anchored. Usually when floating we are at a much lower volume level but there are times at the beach when it is fun to crank it up. In those cases I have a good friend with an X-Star, with an almost identical system to mine, and we tie up side by side, link up, and share sources..........two boats twice the volume. :D

Day in and day out my system plays at 25-50% when on the water. At those levels my alternator easily keeps the two blue tops fully charged. So far I have been very impressed with Indmar's high output alternator. :)

JimN
05-18-2006, 03:27 PM
AZHAWK- They should be able to determine the right size for the cables. If they can't, they're dangerous (no offense to anyone but I don't know their qualifications). I've seen enough cars, trucks and boats that were damaged by bad installations. They should have a chart with the gauge according to current draw and length. My charts aren't handy at the moment but if I need to, I'll see if I can dig them out. IIRC your stock alternator is good for 59A, but if you plan on balls to the wall a lot while the motor is running, don't forget to factor in the motor's current requirements as well. Your new alternator will last a lot longer if you go overboard on capacity and you won't need to replace it in a year(or less).

Diesel- after an hour, what does the voltage drop down to?

zberger
05-18-2006, 03:32 PM
AZHAWK- They should be able to determine the right size for the cables. If they can't, they're dangerous (no offense to anyone but I don't know their qualifications). I've seen enough cars, trucks and boats that were damaged by bad installations. They should have a chart with the gauge according to current draw and length. My charts aren't handy at the moment but if I need to, I'll see if I can dig them out. IIRC your stock alternator is good for 59A, but if you plan on balls to the wall a lot while the motor is running, don't forget to factor in the motor's current requirements as well. Your new alternator will last a lot longer if you go overboard on capacity and you won't need to replace it in a year(or less).

Diesel- after an hour, what does the voltage drop down to?

At a minimum I would run 4 gauge.. But probably just man up and do 0. I only like to do things once.

JimN
05-18-2006, 03:44 PM
IIRC, 4 ga is good for 60A at 15', 14.4Vdc. Real world voltage being lower, 2 ga would be better. If the amps are going to be in the same space, 1/0 with distribution blocks would be OK unless the voltage drops even lower. The chart would be used to size the charging lead, too.

Diesel
05-18-2006, 04:02 PM
Diesel- after an hour, what does the voltage drop down to?

I never checked since it has only happened out on the water. I will check my amps tonight. They have a sick bay flash memory that will record a bunch of max/min values. IIRC is logs lowest voltage.

Goalie_ken
05-18-2006, 04:53 PM
I have a similiar setup.

I chose to use a Battery Isolater / Combiner and a second battery for only starting.

http://www.hellroaring.com/bic75150.htm

I also use a remote switch that can combine both batteries for starting in case of emergency.

This to me seemed to make the most sense. I did not like the idea of having a switch installed and rewiring my accesories This setup will allow both batteries to charge automatically and then isolate the starting battery and will work fine with the stock alternator.

Diesel
05-22-2006, 12:45 PM
Diesel- after an hour, what does the voltage drop down to?

Checked the Kicker amps this weekend and 11.3v was the lowest recorded in the history. :)

zberger
05-22-2006, 01:57 PM
Checked the Kicker amps this weekend and 11.3v was the lowest recorded in the history. :)

Thats not terrible..

I'd say around 10ish you are gettin in trouble.

Are your amps regulated or unregulated?

AZHAWK
05-22-2006, 06:51 PM
Got the boat back on Friday... about 95% complete. (waiting for some cables for the CD changer or something) Anyhow, I took it out to the lake on Sunday after installing 3 new Optima Blue Tops on Sat. (Three batts. total) WOW, WOW, WOW, i am amazed at how loud, and clean sounding this set up is. This thing rocks!!! :headbang: It sounds like an outdoor concert, no joke! Very pleased to say the least. I can finally listen to some tunes while i'm boarding! BTW, The three batts. held up fine. I'm going to add one more to the mix, just to be on the safe side. Four Total.... i know.... that is what they originally suggested! I just had no idea how much current this set up was really going to need. It killed the two original batts. in about 10 minutes. I tried to charge them but they just needed replacing. Better safe than sorry. Thanks for all the feedback and help. - AZHAWK

zberger
05-22-2006, 11:33 PM
Got the boat back on Friday... about 95% complete. (waiting for some cables for the CD changer or something) Anyhow, I took it out to the lake on Sunday after installing 3 new Optima Blue Tops on Sat. (Three batts. total) WOW, WOW, WOW, i am amazed at how loud, and clean sounding this set up is. This thing rocks!!! :headbang: It sounds like an outdoor concert, no joke! Very pleased to say the least. I can finally listen to some tunes while i'm boarding! BTW, The three batts. held up fine. I'm going to add one more to the mix, just to be on the safe side. Four Total.... i know.... that is what they originally suggested! I just had no idea how much current this set up was really going to need. It killed the two original batts. in about 10 minutes. I tried to charge them but they just needed replacing. Better safe than sorry. Thanks for all the feedback and help. - AZHAWK

I am glad everything is working out good for you, got any pictures?