How much is too much? Battery question...

**AuMDLST** · 09-04-2009, 10:27 AM

RE: How much is too much? Battery question...

It is highly unlikely that you will play the system at the RMS of 3000 watts - thats like 250 amps. Your alternator (factory 100 amp) cant keep up while running
and the batteries - even kinetics (KHC2000) - wont last but maybe 30 minutes (two batteries fully charged with engine off).

You may run at 50% RMS (1500 watts) (appx. 125 amps) and the above scenario would maybe get you one hour with two fully charged (100 ah) batteries - engine off.

If you are really interested in approaching the entire 3000 watts - you will need to upgrade the alternator (check out Balmar - 150 amp)

Even with the Balmar - You will need more than two batteries to play the stereo for a decent amount of time (4 batteries - 50% rated RMS - 2 Hours)

Some spec reading material
http://www.odysseybatteries.com/batt...2150series.htm

**EarmarkMarine** · 09-04-2009, 12:50 PM

Re: RE: How much is too much? Battery question...

flaudia,

I'll leave the debate over golf cart batteries versus Kinetik to others as I see strong points for either argument.

I feel three total batteries (one starting in reserve and two stereo) and 2000 watts system power is about the limit for a factory alternator. At this level I recommend an automatic combiner/separator smart solenoid for preservation of your alternator. I'd also recommend at minimum a 20 amp dual-bank multi-stage shore AC charger so that you're less dependent on your alternator for the preservation of your batteries. A bigger charger would be better.

But when you step up to 3000 watts things get considerably more complex and the challenges domino into every aspect of your charging system.

3000 watts divided by 12 volts times 60 percent efficiency times 50 percent of maximum output (given the transient nature of music and just a bit of restraint) would be over 200 amps of draw off what I'm assuming is a 100 amp factory alternator. Add to your current draw the demands of several depleted (10 1/2 to 11 volts) batteries which could initially pull 25 amps a piece. Its a clumsy equation but you get the drift.

Multiple fully charged batteries do not present a challenge but a few discharged batteries can toast an alternator.

An alternator can't properly restore and condition batteries. You'll have to be heavily dependent on shore AC power. Each stereo battery, depending on it's capacity and the degree of optimum which you want to achieve, deserves 20 to 40 amps of charging capacity to desulfate. This translates to longer playtime and longer life span.

A serious alternator upgrade is in order and Balmar would be the right avenue.

You could run as many as four dedicated stereo batteries if you break them down into two cascading banks so that no fully depleted bank is seen by the alternator until the bank before it is fully restored. An elaborate control system is needed to facilitate the three or four different modes of operation (ie; at rest, boat running, shore AC charging).

It might also be a good time to start converting over to high efficiency Class D amplifiers.

I know this sounds unduely complicated but these are real issues when you're playing at that level. Please don't shoot the messenger. Hope this helps.

David
Earmark Marine

**Mikeski** · 09-07-2009, 02:04 PM

RE: Re: RE: How much is too much? Battery question...

flaudia,

I am currently running two Kinetik 2400's dedicated to my stereo, they replaced a pair of Exide golf cart batteries I used previously. For the price I cannot recommend the Kinetik batteries, if I were starting over I would not go back with these. There are several other factors that need to be considered. In my boat the batteries are readily accessible in the hatches. Takes me no more than 5 minutes to gain access to the top of the batteries, and I have room to run them upright inside a marine approved battery box. This said, there is really no reason for me to run the expensive AGM batteries, I could get by with the significantly cheaper traditional lead acid batteries.

One member here, Harold, a good buddy with Grant is just going through a battery replacement. Harold previously had 11 Optima blue tops (that's no typo). He had 4 in the back of each rear storage compartment mounted in their sides plus another in the factory location in his 2003 SAN. This time around he is going with 4 large 12v Interstate lead-acid batteries or a similar sized AGM battery. The new setup will provide comparable run time to what he had with his Optimas. After just a few years 3 or 4 of the Optima batteries were bad.

My stereo is running at about 3000 watts (of class D/T/H amps). I am using the stock 100amp alternator. At my listening profile it keeps up with the load. In reality I probably average somewhere around 20-25% average wattage while listening, maybe double that when a favorite song comes up on my playlist.

I believe the key to keeping your alternator alive is the combiner/relay/isolator. My device of choice is the Yandina C150/160. David sells another option: http://www.earmarkcaraudio.com/Xcart...261&page=1

I would not hesitate with the amp upgrade...

I would also recommend a digital voltmeter if you don't have one already.

**flaudia402** · 09-09-2009, 10:54 PM

Well perhaps if I lay out what exactly my stereo consists of currently, and what I plan to upgrade in the next few months, then perhaps you can tell me what battery set up to go with.

Current Set up:

Pair of NVS Prodigy Tower Speakers powered by a Kicker ZX850.4 (Bench tested at 1100 watts)
(1) JL12W7 in a sealed box built to spec powered by a Kicker ZX750.1 (Bench tested at 950 watts)
The factory Polk Momo interior speakers were rewired with the one Clarion powering the rear four speakers and the other clarion powering the two bow speakers in the front. I believe the Clarions are pushing together around 400 watts.

That said, currently my system consists of roughly 2400 watts. The battery set up is the same as factory. The stereo is wired to the one OEM battery. I always have my Perko switch said to both. I never let the battery drain lower than 12 volts and consistently stay at around 13-14 volts.

Future Set up:
I would like to change out one of two things. Either change out my current JL sub for a more efficient subwoofer possibly one from FI audio. Either that, or keep my current JL subwoofer, and put a Kicker ZX1000.1 in place of the 750.1. The way Kicker rates their stuff I imagine this will probably be closer to the 1300-1500 watt bench tested range.

I would also like to add an extra pair of NVS Modus speakers. These require just around 250 watts at 4 ohms. Still unsure about which amp from Kicker to power these (I would like to stick with Kicker since my other amps are Kicker as well).

Depending on power I will be increasing my stereo wattage from roughly 2400 to more along the lines of 3000 or so. Now, I understand I won't be utilizing all 3000 watts, and I am certain there are boats on this site as well as some done by Earmark (The Black SAN 220 owned by Robert - BigGris) that are pushing similar wattage. Please have a look at what I'm doing and give me the best option for batteries. I have gone on Kinetik's site and looked at their power cell calculator and they have recommended other options (Two HC1800's for just the stereo).

Any advice would be appreciated. Thanks!

**EarmarkMarine** · 09-10-2009, 11:59 AM

flaudia,

The kinetik battery calculator pertains to a system's total wattage in relationship to immediate demands and is not a good representation of 'at rest' performance. Their amp/hour specs are a batter gauge for the typical marine application.

Your systems efficiency, your music and the volume will all affect the 'at rest' calculation. A single Kinetik 2400 would probably deliver 2400 watts for one hour before its reduced to 10.5 volts.

So two 2400s at 1200 watts (that's alot!) could deliver 4 hours of constant play time according to crude estimates. Keep in mind that two depleted 2400s are probably going to initially draw a collective 80 amps without the stereo on and without boat operations. I think that is the absolute limit without getting into some very complex scenarios. And at that level I would highly recommend a combiner/separator with a parallel bypass/isolation switch plus a Kinetik 80 amp charger (about 4 hours restoration time on average).

Putting your JL 12W7 in a bass-reflex enclosure will be the equivalent of doubling your power. Still, 1000 watts would be nice. Properly powered (and that's a tall order) and properly loaded (bass-reflex) the W7 is top dog (as in woofer). If you want to stay small and gain a bit more efficiency look at the Boston Acoustics SPG555 with possibly the SPG-TR passive radiator.

David
Earmark Marine

**flaudia402** · 09-10-2009, 02:42 PM

David,
I appreciate your responses. They've been very helpful so far. I don't however generally play the stereo past 15-25% capacity when at rest. If I do crank it up, I always make sure the subwoofer is turned down to almost nothing since I realize that it takes the most voltage. I generally let the tower speakers play most of the sound when at rest.

When cruising or pulling someone is mainly the only time I crank up the stereo. Even then, I generally keep the interior speakers on the WS-420 which is what the subwoofer is wired to as well, to about 1/2 way on the knob, with the tower speakers all the way up.

So with that said, I see that the black SAN 220 you guys did has three optimas which you guys kept even when you did the upgrades with the additional pair of wetsounds and the additional 1000 watt amp for the JL.

Could you guys build me a better box for my JL sub tuned for the boat? The reason I went with sealed was because I was afraid if I ported it wrong the frequency would be completely off and it would sound terrible. You're welcome to PM me about pricing and details. Thanks!

**Mikeski** · 09-11-2009, 12:32 AM

you can play around with my little battery calc spreadsheet...

Attached Files

alternator_calcs_427.xls (20.5 KB, 50 views)

**EarmarkMarine** · 09-11-2009, 11:51 AM

flaudia,

Everyone's usage is different and from your comments it sounds like you're dialed in on what your battery needs are.

We select bass-reflex alignments for a low and linear response curve. This is in contrast to those tuned for more peak output whith obvious tonal abberations. The alignment really isn't that fragile in a boat provided the locker is large enough, the woofer and port are initially loaded into an unobstructed path and the locker is adequately vented.

I'll send you some details.

David
Earmark Marine

**EarmarkMarine** · 09-11-2009, 11:55 AM

Mikeski,

Awesome spreadsheet. You, Grant and a few others have really been on top of this big picture for a long time.

Too many wakeboarders ignore their battery maintenance as if its their car when they should be treating them more like a tournement bass boat.

Everytime I see someone complaining in a post about their experience with this or that overpriced battery, I know its more likely to be improper maintenance.

It's usually like a $5k invenstment in the stereo with a $35.00 trickle charger?

David
Earmark Marine

How much is too much? Battery question...

How much is too much? Battery question...

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