Upgrading Stereo, need help on battary power req.

[Limited-Time]

I am doing a stereo system upgrade and need help/info on the additional batteries required, like how many, (1 or 2 additional) what type, (reg. vs. Deep cycle) and, installation configuration. I will be adding a total of 580 watts RMS of amplification using 3 separate amps. Thanks in advance. BTW the boat is powered by a '92 Merc 200 HP OB, I am not sure of the alt. output.

 

[vipzach]

Re: Upgrading Stereo, need help on battary power req.

That sounds like fun! I would put in two batteries if you have room. I would also use deep cycle batteries, they last alot longer just running the stereo. Use a seperate battery for starting(reg/starting battery). Why are you using three aeperate amps though? My boat has one battery batt for stereo, the other for starting. One 4 channel amp, powering a 10" sub and a setup speakers. It all sounds really good and loud.

 

[Limited-Time]

Re: Upgrading Stereo, need help on battary power req.

vipzach,<br />Thanks for the reply. The reason for 3 amps is I want to run 6 speakers and supply all 6 with 80 watts of power, so I got 1 80 X 2 channel amp, 1 80 X 4 channel amp along with a powered sub woofer (10" with a 100 watt Amp) that makes 3. We plan on rock'n the lake this summer.

 

[ZmOz]

Re: Upgrading Stereo, need help on battary power req.

Geez...I hope you don't go to any of the lakes by me...

 

[cuzner]

Re: Upgrading Stereo, need help on battary power req.

Dude I'll hear ya up here in Canada!..Get 2 batteries and a switch. Your up close to 50 amps If you crank it up. You will probably be averaging about half that (or you'll be deaf).You will be better off with deep cycle.I would suggest To run a seperate set of wires, from your house (not starting) battery. And instal a fuse panel dedicated to your electronics.50 amps is alot for factory wiring, and maybe too much.<br /><br /> Jim

 

[18rabbit]

Re: Upgrading Stereo, need help on battary power req.

Yeah, I estimated close to 48-1/3 amps at 12vdc. But you won’t be running all of the amplifiers at full power, i.e. clipping. That sub amp may go near full power. When a subwoofer’s motor and supporting amp are matched, the speaker often bottoms out before the amp clips.<br /><br />A deep cycle will only give you about 1/2 of its rated capacity. A 100hr battery has 50amps available for you. Also keep in mind the bigger the percentage of demand from a battery, the less overall capacity the battery will have. That 100aHr, group 27 battery with a 25amp demand is good for about 1hr and 8mins. You won’t get 50amps out of it. With two batteries you half the demand on the battery, but get more than twice the energy from it. Ideally you do not want the drain on a battery to exceed 5% of its capacity. In reality, we always exceed that 5%.<br /><br />I’ll give you an 8amp demand for the subwoofer amplifier, and I will guess about 30% (12amps) on the other two amplifiers. 8+12=20amps/12vdc. Vipzach is right on with the suggestion of two, group-27, deep-cycle batteries wired in parallel. That’s about a 10% drain on the bats, should keep your floating discothèque noisy for about 4 to 5hrs, not considering any juice put back into the bats from the alternator.

 

[amirm]

Re: Upgrading Stereo, need help on battary power req.

Actually, the typical car amplifier uses a "class AB" design that is only 50% efficient. The switching power supply that feeds the amp is 80% efficient (12v input is boosted to a higher voltage to get higher power). This means that you get only 40% total efficiency out of the amplifier forgetting losses in the power lines. Using your 580W RMS, this means that power consumption on the input will be 1480 watts or a whopping 120 amps! <br /><br />Of course, it is hard to imagine that you will drive the amps at full capacity all the time. But you are talking huge power consumption here. You will be able to raise the temperature of the lake a couple of degrees with heat generated in this setup .<br /><br />You did not say anything about whether you are running the stereo with the engine on or off. If it is off, you better get a couple of batteries as one may not last long at all. Standby current (i.e. with zero volume) alone is bound to be over 10 to 15 amps in such a setup. I would definitely have a separate starting battery as otherwise, you may get stranded. If you are running the engine, then you may be better off assuming you have a beefy alternator.<br /><br />Your other consideration needs to be charging. If you run the stereo without the engine, you will need to run your boat quite a while to replenish the batteries. Otherwise, you will destroy the batteries after a while from undercharging.<br /><br />My advice, back down from your power requirement . You can easily share multiple speakers on the same amp, assuming the impedance on the speakers is not too low. Boost the sub power to 200 watts and then back off the satellites down to 40 watts. That should be plenty. 100 watts is really not that much for the sub and you are going to get fair amount of distortion out of it. Higher wattage lets you concentrate the power where you need it: scaring off the fish from the bottom of the lake .<br /><br />Amir

 

[18rabbit]

Re: Upgrading Stereo, need help on battary power req.

If you are serious about a constant 120amp/12vdc load, he’s looking at a minimum of three group-8D batteries, 160lbs…each! Even then you are looking at a load that is close to 17% of the battery bank’s capacity, about 240a/hrs each, 720a/hrs total. The next discussion should be on how to get 360a/hrs back into those batteries.

 

[Limited-Time]

Re: Upgrading Stereo, need help on battary power req.

Thanks, you guys rock!! The set up will be run both at rest, lower (normal) volume setting longer playing times, and under way, higher (gotta be able to hear the music while buzzing across the lake) volume but shorter playing times. We'll go with twin deep cycle batteries and use a battery switch to isolate the cranking battery.<br /><br /> Is there a system that will automatically isolate the cranking battery when the engine is turned off, and switch back over and charge all the batteries when restarted, or do I have to use a manual switch? I'm also planning on adding a 110 volt shore powered battery charger set up similar to those used on fishing boats with trolling motors to recharge the batteries when the boats no in use.<br /><br /> Is there a battery monitoring system available that indicate the batteries “current state/charge level” so I’ll know when the batteries are low enough to recharge? I know you can trash a deep cycle battery if you do not drain and charge them correctly. Again, thanks for all the input.

 

[vipzach]

Re: Upgrading Stereo, need help on battary power req.

Here is a link to a "auto" switch, it is similar to the one I use. I think they have a 50A and a 150A version. I like it because you don't have to remember to turn the switch after the boat is started. Should also prevent the huge power transfer that may happen when you move the selector on a manuel switch. Sea Sense also makes one. There are battery indicators that you can hookup to watch what is left in each battery. <br />I would be interested to know the proper way to charge/rechrge a deep cycle battery. I haven't had mine long, but would like to keep it as long as possible.

 

[vipzach]

Re: Upgrading Stereo, need help on battary power req.

Sorry, forgot the link!<br /> http://www.bluesea.com/product.asp?Product_id=53476

 

[Limited-Time]

Re: Upgrading Stereo, need help on battary power req.

Thanks vipzach. I know you can short charge NiCad and reduce it holding cap. And I think you can do the same with a deep cycle. I'm sure some one here on iboats knows.

 

[vipzach]

Re: Upgrading Stereo, need help on battary power req.

Hope it helps you. I always charge mine up when I get home using a uatomatic charger that I think is a 2A charger. Maybe I should not be.

 

[cuzner]

Re: Upgrading Stereo, need help on battary power req.

You can get some good quality 4 stage chargers.bought mine at Cabbella's, less than 100$ for 12 amp 2 bank version.You'll need alot more amps for your floating sound system,at least 20. Only instaled mine this year, but reports on them is great.Just plug in and it does all the thinking for you.<br /><br /> Jim