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jsmail

Number of Batteries and Size

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jsmail

My current setup has a dual battery bank with a starter battery on each bank, (this is how it came) and I added a cheap deep cycle battery on the bank I use when playing the stereo to get me through the season. I am at a point that I would like to upgrade and I am looking for some feedback. At the urging of the dealer I use, I will be using Shuriken AGM batteries. My plan is to replace the starter & deep cycle battery on one bank and leave the other starter battery on the other bank. I am not sure if I should use one 4000 watt 140 ah battery or two 2400 watt 120 ah batteries. Space really isn't an issue because I can make either setup fit. And although I would prefer not to use shore power I do have access and can if I need to. I also am not opposed to using two 4000 watt batteries but I am guessing that would be a bit of overkill and a bigger strain to my alternator.

We definitely have a mixed use for the stereo... sometimes we may spend hours out with the boat running while we do all of our activities, and then we may go 2-3 hours in the evening listening to the stereo at a high level while we are parked. When I asked this question of my dealer of which setup to use he just said either setup would work and should be more than enough for what I described. I am just looking for feedback or suggestions on which may be the preferred method.

Here is the amps and watts I am using in my boat:

Wet Sounds Syn 4-800 watts bridged

Wet Sounds SD4-1360 watts 2ohm stereo

JL Audio XD600/1v2-600 watts mono

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MLA

In regards to a strain on the alt, I larger Ah battery 50% discharged is a lighter strain then a smaller Ah battery 100% discharged.

You will likely want to add a charger to the mix. 2-3 hours at anchor with a short trip back to the dock, will leave you with a discharged battery.

If space for 2 house batteries is not an issue, I like the 240Ah option.

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Bill_AirJunky

Whatever batteries you use, install a smart charger...and use it. You will prolong the life of your batteries and alternator.

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jsmail

In regards to a strain on the alt, I larger Ah battery 50% discharged is a lighter strain then a smaller Ah battery 100% discharged.

You will likely want to add a charger to the mix. 2-3 hours at anchor with a short trip back to the dock, will leave you with a discharged battery.

If space for 2 house batteries is not an issue, I like the 240Ah option.

So with 2 batteries it doubles the Ah??? I wasn't sure how that worked.

Is playing the stereo 2-3 hours going to drain the two 2400 watt 120 Ah battery setup?

Also is voltage going to hold steady?

Edited by jsmail

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MLA
So with 2 batteries it doubles the Ah??? I wasn't sure how that worked

In parallel, yes

Is playing the stereo 2-3 hours going to drain the two 2400 watt 120 Ah battery setup?

Not nearly as fast as a single 140Ah

Also is voltage going to hold steady?

Again, the voltage level will hold out longer than a single 140 Ah bank with the same load.

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minnmarker

Whatever size and type batteries you decide on put one of these between them:

https://www.bluesea.com/products/7610/SI-ACR_Automatic_Charging_Relay_-_12_24V_DC_120A

Very slick. Run cables from each positive terminal to the ACR and put the shore (smart!) charger on the stereo battery.

When docked, the shore charger charges the stereo battery first, then the boat battery (if needed) after the stereo battery is topped off.

When underway, the alternator charges the boat battery first, then the stereo battery after the boat battery is topped off.

When engine is off away from the dock, the stereo draws only on the stereo battery, not the boat battery - preventing you from stranding yourself.

Your stereo will run off the alternator when underway but only off the stereo battery when engine is off.

And it does all that without you having to do anything except plug in your smart charger when docked. Who needs switches?

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MLA

The OP's 2015 may already have the ACR and proper switch, but just to clarify a couple of things.

When docked, the shore charger charges the stereo battery first, then the boat battery (if needed) after the stereo battery is topped off.

If using a dual bank charger, which is recommended, and the switch, charger and ACR are wired properly, the charger will charge both banks at the same time and ACR has no impact.

When underway, the alternator charges the boat battery first, then the stereo battery after the boat battery is topped off.

The Blue Sea 7610 ACR is not a distribute on demand device. Its way simpler and has an open and close voltage threshold. This is based on the voltage of each bank, not really based on alternator voltage. The main cranking bank will always see alternator input when the engine is running. Depending on voltage, the ACR will either close/combine the house bank to the main bank or open/isolate the house bank from the main cranking bank. There will be plenty of times when both banks are being charged, as opposed to one being charger to full before the other sees any charger.

I wanted to make this distinction, because there are devices that will distribute the alternator charge based on need. These type of devices typically have 3 large studs, one for alt and the other 2 for the batteries. The ACR has only 2.

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NCSurfing

Wetsounds has a partnership with XS batteries and I swear by them. I have an XP3000 which would give my 2400 watt Wetsounds system 4-5 hrs of docked play time between charges. I just added a second to run in parallel off the first in the perko #2 position (as I added another amp and am at 3000 watts) thus, am hoping to get even more playtime.

In any event, I realize your question wasn't about what kind of battery (although I would reconsider) however, I am an advocate of a battery bank in parallel - the benefits of which MLA outlined

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MLA

AGM's certainly have some pros over wet cell, but Ah is Ah and amp draw is amp draw, regardless of battery type. A bank of wet cell can support a large stereo just the same and will good maintenance, yield good life.

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gorilla

Anyone have a good source for a calculator to determine Ah capacity and stereo run time? All the ones I've found seem WAY off, including XS Power's calculator. It says I need 44 XP3000 batteries to run a 1000w amp for 6 hours.

I've got just under 5000w of stereo and 3 XP3000 and 1 XP2000 (overkill, I know, but never want to run out of power). I've ran the stereo at pretty high volumes for 7 hours and my voltage was reading 12.1 (roughly 50% charge still). Just curious how to calculate it for future projects.

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David

All the on-line calculators I have seen have so many flaws they are useless.

It's impossible to have a highly accurate calculator because there are so many factors with so many variables per each factor.

You apply the 'at rest' true voltage, perhaps an average of 12.4 volts.

You apply the collective amplifier efficiency based on the type and the load impedance channel by channel. Note, with all type amplifiers the efficiency changes at different load impedances. Lower impedance loads means lower efficiency.

In the same way, add up the amplifiers collective channel by channel and amp by amp power.

You estimate how far off full non-clipping power you are normally playing the system at rest. - 3 dB = 1/2 power. - 6 dB = 1/4 power. - 10 dB = 1/10 power. Efficiency drops somewhat at lower power levels and increases somewhat at higher power levels.

Divide the wattage by the voltage to arrive at an amperage.

Here's the most difficult factor to figure. So far we have a purely DC calculation. However, music is very transient in nature, in other words, quick bursts of AC. So the music calculation might be 20% of the DC numbers. And the type of music makes a difference. Continuous-bass-heavy music will consume power differently than other types.

Even system design, installation and tuning can have a profound impact on system efficiency. So the identical system executed by different people may vary widely.

A/Hs are based on empty being 10.5 volts. You do not want to exhaust consumer-grade deep-cycle battery levels below 50%....so 11.8 volts absolute minimum. So you are now using half the A/H spec as the bottom point.

Most will splice some real world experience together with their method of calculation to simplify the formula.

Based on how impossible it is to get a reliable calculator, you can't beat actually measuring the stereo battery bank voltage immediately after your longest stay at rest.

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NCSurfing

Anyone have a good source for a calculator to determine Ah capacity and stereo run time? All the ones I've found seem WAY off, including XS Power's calculator. It says I need 44 XP3000 batteries to run a 1000w amp for 6 hours.

I've got just under 5000w of stereo and 3 XP3000 and 1 XP2000 (overkill, I know, but never want to run out of power). I've ran the stereo at pretty high volumes for 7 hours and my voltage was reading 12.1 (roughly 50% charge still). Just curious how to calculate it for future projects.

Sounds similar to mine although mine is at a smaller scale. How is yours hooked up? Keen to know in the event I decide to expand....

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gorilla

Sounds similar to mine although mine is at a smaller scale. How is yours hooked up? Keen to know in the event I decide to expand....

The 3 big batteries are my stereo bank and the XP2000 is my backup battery........................but I run the battery switch on ALL and have never isolate the banks. I also have a Stinger 60 amp Power Supply in there to charge every time the boat comes off the water. I also have a Mechman 240 amp alternator to keep it topped off while underway.

Stereo is as follows

SD2 powering my Exile Big 15 sub

SD2 powering 2 sets of Rev 8's

SD2 powering a set of Rev 10's

SD4 powering my 8 SW650's

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MadMan

I stopped buying deep cycle batteries 20 years. I am pretty hard on them and would have to buy new every couple years since they only came with a 1 year warranty. I just buy standard automotive batteries now and just deep cycle them. They come with a 3 year free replacement warranty and are always exchanged without a problem. Ends up being much cheaper.

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NCSurfing

The 3 big batteries are my stereo bank and the XP2000 is my backup battery........................but I run the battery switch on ALL and have never isolate the banks. I also have a Stinger 60 amp Power Supply in there to charge every time the boat comes off the water. I also have a Mechman 240 amp alternator to keep it topped off while underway.

Stereo is as follows

SD2 powering my Exile Big 15 sub

SD2 powering 2 sets of Rev 8's

SD2 powering a set of Rev 10's

SD4 powering my 8 SW650's

Nice! Assume your bank of 3 is in parallel? I used the 2000 to replace the factory deep cycle (#2) in the stock location/box and then wired my 3000 to it in parallel. I mounted my HF1215 intellicharger in there as well so I can charge when I'm back at the dock. What kind of idle play time do you think I will get off this setup at 3100 watts? Last summer I had only the 3000 running 2400 watts and that seemed to get me 3-4 hrs of play time. I went with the current setup figuring I could add another 3000 if I wanted more play time.

Curious why you never isolate the bank? Are you worried about not having enough juice to start - perhaps that's why you carry the 2000 as a backup?

Edited by NCSurfing

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David

gorilla,

Charging batteries with a blunt power supply versus a three stage smart charger would concern me.

Even though some power supplies claim to be intelligent I have seen many swollen batteries due to use with a power supply.

When the load is gone the power supply should be gone also, especially as batteries get older with a little wear and tear.

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gorilla

Nice! Assume your bank of 3 is in parallel? I used the 2000 to replace the factory deep cycle (#2) in the stock location/box and then wired my 3000 to it in parallel. I mounted my HF1215 intellicharger in there as well so I can charge when I'm back at the dock. What kind of idle play time do you think I will get off this setup at 3100 watts? Last summer I had only the 3000 running 2400 watts and that seemed to get me 3-4 hrs of play time. I went with the current setup figuring I could add another 3000 if I wanted more play time.

Curious why you never isolate the bank? Are you worried about not having enough juice to start - perhaps that's why you carry the 2000 as a backup?

You have to install these batteries in parallel, if not, you get 24v and will fry everything.

Like David said, only you can estimate your system run time based off of what you've seen in the past. I'm guessing that you might get 5-6 hrs of play time if you run the XP2000 and XP3000 together. Add another XP3000 and you can go all damn day.

I never isolate them because the first few times I went out with the system, totally forgot to turn the switch. The lowest I have ever seen my voltage gauge was 11.8v when I was running a similar wattage Exile setup (had class AB amps, so more power draw). Boat started up just fine at that voltage (4 batteries had plenty of cranking amps). I watch my digital voltage gauge like a hawk now and would just start the boat up before it drops below 11.8v, which I've never seen. It's a little hard on my alternator to try and charge up 4 batteries, but I put it on the charger right after I get it out of the water. The boat goes from the party cove right on the trailer and back to the condo/house/what ever to charge up. The next morning, the batts are reading full charge and ready for another day out on the water.

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gorilla

gorilla,

Charging batteries with a blunt power supply versus a three stage smart charger would concern me.

Even though some power supplies claim to be intelligent I have seen many swollen batteries due to use with a power supply.

When the load is gone the power supply should be gone also, especially as batteries get older with a little wear and tear.

David, I've been running the Stinger with the SCM, which is supposed to make it switch into a charging mode. Have been running this setup for 5 years and have never had a problem. Batteries are always charged and never a hint of problems. I just swapped out the Kinetik batteries for XS Power batteries because I was moving to AZ and it was going to take a bit of fab work for my stereo guy to change them out. But the Kinetik's were working just fine, just figured 5 seasons with heavy use was enough to warrant new batteries.

Now you have me a little worried................... :(

Edited by gorilla

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David

gorilla,

My comments are based on decades of experience with soundrooms and demo vehicles.

All used power supplies similar to the Stinger, Cascade, & Kinetik. All claimed "intelligent". All had supplemental battery banks. And all where in use six long days per week. And all experienced battery life shorter than what we expected.

So we used an AC relay to shut down the power supply and a solenoid to isolate the batteries at the exact same time the display was shut down. Overnight the battery bank was then maintained by a small amperage 'Smart' Ctek charger.

The battery lifespan now became 5+ years hammering on the supply all day six days a week.

I've also had experience running very large audio systems on cruisers where the gen supplied AC to DC power supplies (like two 90 amp models in parallel)rather than overwhelming the onboard charger/convertor. In the same way, once the load was gone the power supplies where automatically disabled. And we immediately switched to a dedicated smart charger.

There's little doubt that the power supply would be safe when a large bank, capable of dissipating lots of current, is low and in need of a bulk charger. My concern is after that brief period.

So I'm not saying "don't do it" but just sharing my concern based on my own experiences and adaptions.

Edited by David

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jsmail

So what is everyone using for a shore charger???

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AJWest

So what is everyone using for a shore charger???

I went a bit much on overkill on my onboard charger but found a screaming deal on a ProMariner Pro Nautic 50 amp charger and got it. The 50amp charger also gives me the headroom when I add a 4th battery this year for LED's and an extra monoblock amp for my new sub. Using the 10% amp hour rule is safe to decide on what size charger you need. I would put money that the most popular charger is the ProMariner 20amp for dual or triple battery set ups. Anything more than 3 large capacity batteries and you'll need to step up the charger beyond the common 20amp charger in my opinion to feel safe and to adequately desulfate a depleted bank of batteries.

Edited by AJWest

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David

Adding to what AJ stated about shore chargers selected at 10 to 15% of the collective batteries A/Hs, view the amperage capacity of a charger as the total and not the individual banks. So for example, don't try and run one bank of a 2-bank 20 amp charger to two 6-volt batteries in series with 225 A/Hs for those two batteries. Consider the capacity of that 20 amp charger to be 10 amps per bank.

One size of charger does not fit all. Selecting a charger is about several factors. One, the collective battery(s) A/Hs. Two, your usage in how far down you normally deplete your batteries. Three, do you occasionally use the charger also as a power supply at a slip for instance. In addition to a few other factors.

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jsmail

So if I was going to use two AGM batteries on one bank with 120A/Hs & 2400 watts and a starter battery on the other bank, would a ProMariner 20amp triple bank setup work? I will not be running the batteries completely dead and really the only time I think I will need to use the charger is when we are ending the night floating with the music on and making the short trip back to the dock.

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David

Yes, that charger would work.

Two of the three banks would be wired individually to the two batteries that are in parallel on the stereo bank. In this case the two charger banks would behave (profile and charge) as a single bank, which is fine because the two batteries fixed in parallel are functioning as a single battery. That's making use of all the chargers internal drivers with an effective 60 A/Hs per each charger bank. Just try and keep from depleting your stereo bank below 12.0 volts. The starting battery bank of the charger should never get much of a workload. Even if you run the stereo bank down at rest, combine the two banks on a short trip back home, and moderately play the system on the way back, the starter battery won't be syphoned too much, as long as you keep the voltage threshold from falling below 12.0V.

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NCSurfing

Yes, that charger would work.

Two of the three banks would be wired individually to the two batteries that are in parallel on the stereo bank. In this case the two charger banks would behave (profile and charge) as a single bank, which is fine because the two batteries fixed in parallel are functioning as a single battery. That's making use of all the chargers internal drivers with an effective 60 A/Hs per each charger bank. Just try and keep from depleting your stereo bank below 12.0 volts. The starting battery bank of the charger should never get much of a workload. Even if you run the stereo bank down at rest, combine the two banks on a short trip back home, and moderately play the system on the way back, the starter battery won't be syphoned too much, as long as you keep the voltage threshold from falling below 12.0V.

David - what's the best way of monitoring your stereo bank voltage? My setup is exactly as jsmail is considering his. I have an AGM start battery on #1 and 2 XS Power AGM batteries in parallel on #2 for stereo. I start and run the boat on 1+2 and switch to 2 when idle and listening to tunes. At night, I hookup my XS Power Intellicharger (HF 1215 = 15V) to the bank and top them off. Any changes to consider? Main thing is that I have not (nor previously understood) the importance of not letting them drop under 12V...

Thx in advance!

Edited by NCSurfing

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