Will I need another battery?

[Shooter]

I currently have two Optima blue tops running two amps (170x4 watt ZXi6406 for the 6.5 in boat speakers & 1000x1 Watt BXi16060 for a large Boston SPG55 sub).

The system works well, but I would like to add 2 Wet sounds pro80 tower speakers (maybe even 4). I will probably purchase Wet sounds Syn2 (2x200 watt) to push the tower speakers.

This sounds like a lot of power running off of two batteries, especially when the alternator isn’t running. I don’t want to install a third battery. Do you think I could get by without? How many batteries are people running with similar systems and how long can you keep the system running without the boat running?

[EarmarkMarine]

RE: Will I need another battery?

Shooter,

Play time will depend on how hard you play your system at rest. Even with your dual battery set up its important to have a shore AC charger so you're not solely dependent on the alternator for restoration. If you go from two batteries to a total of three, I would switch over from a battery switch to an automatic combiner/separator for the protection and preservation of your alternator.

David
Earmark Marine

[99ProAir]

RE: Will I need another battery?

I have two amps powering a sub and Pro 80's. I run on two batteries like you. I purchased a shore AC charger from Earmark and it has been great. I have run my stereo at the sandbar for 8 hours with no issues at all. When the boat is on the lift at the end of the day, I just plug into the charger overnight and the batteries are all charged the next morning. I also have an automatic combiner/separator to protect my alternator as David suggested.

[Mikeski]

RE: Will I need another battery?

as seen elsewhere...

Shooter, you might considering dumping those low amp-hour blue tops as many other WW'ers have done and going with something a little more stout. For comparison purposes a group 34 blue top is only rated at 55 amp hours. There are several group 31 AGM batteries putting out in excess of 100 amp hours each. You could also go with two golf cart batteries, that would bet you up to 225 amp hours for the cost of one blue top with the equivalent output of four group 34 blue tops.

The system you describe will probably run 2-4 hours off a 200+ amp hour battery bank depending on how hard you drive the bass. If you turn your sub down you can probably run the system more than 6 hours.

Battery = Gas Tank
Volume control = throttle

Get yourself a digital voltmeter so you can watch the battery levels.

[Socbum]

Re: RE: Will I need another battery?

as seen elsewhere...

Shooter, you might considering dumping those low amp-hour blue tops as many other WW'ers have done and going with something a little more stout. For comparison purposes a group 34 blue top is only rated at 55 amp hours. There are several group 31 AGM batteries putting out in excess of 100 amp hours each. You could also go with two golf cart batteries, that would bet you up to 225 amp hours for the cost of one blue top with the equivalent output of four group 34 blue tops.

The system you describe will probably run 2-4 hours off a 200+ amp hour battery bank depending on how hard you drive the bass. If you turn your sub down you can probably run the system more than 6 hours.

Battery = Gas Tank
Volume control = throttle

Get yourself a digital voltmeter so you can watch the battery levels.

Great advice from the local expert!

Seriously consider the dual golf cart configuration. More "play time", easy to implement and much lower cost to maintain.

[AuMDLST]

RE: Re: RE: Will I need another battery?

I would look at the group 31 AGM's before getting into golf cart batteries. GC Batteries are not maintenance free - therefore constantly needing to check
water/acid level. Besides that, you are already wired for dual batteries (12v). In order to use the GC batteries you will need to rewire your battery connections
to allow for a series connection rather than the parallel you currently have.

[ZANDERSANTE]

I'm not following everyone on the advice of the battery automatic combiner/seperator to protect and preserve my alternator..? I have one standard marine battery on one bank and 2 optima yellow tops in parallel on the other bank.. When boarding I turn the selector to both, and when I'm sitting around blasting my stereo I run it off the yellow tops.. I keep the standard for a starting battery if needed and I plug the yellow tops in when I go into dock..

Dave, can you elaborate alittle more on the alternator issue?

Thanks!

Neil

[EarmarkMarine]

Neil,

Your situation provides a good example. With your set-up its possible for your alternator to simultaneously see two depleted batteries (initially pulling 50 amps to recharge) plus a 50 amp stereo draw plus 15 amps or so for boat operations without DC lighting. This would exceed your alternator's capacity thereby creating alot of stress and heat. An alternator that runs twice as hard and hot may only last half as long.

An automatic combiner/separator (Sure Power, Blue Sea, Yandina, etc.) automatically isolates the two banks once the voltage drops below a predetermined threshold. More importantly, it automatically combines the two banks once a separate voltage threshold is reached. But it won't combine until a number of conditions are met including adequeate charging system RPM, voltage of starting battery and voltage of overall charging system. If you overtax the alternator by continuing to hammer the stereo off depleted batteries, the combiner/separator maintains isolation between the banks until the situation is corrected. A timed delay keeps the device from frequent responses to temporary conditions.

With independent meters and manual switching you could monitor your conditions and take the same alternator preserving precautions. The automatic combiner/separator is simply more concise and convenient.

We like the SurePower device in particuluar and represent it within our on-line store at www.earmarkmarine.com.

For more product details read http://www.surepower.com/pdf/separatorinterconnect.pdf

Also, I want to reiterate that none of this including an upgrade alternator can replace the benefits of a shore AC multi-bank multi-phase charger.

David
Earmark Marine