I have a battery/power question. (Marine Head unit install)

I recently picked up a Fusion waterproof marine head unit and installed it into the Kayak. Along with a set of waterproof speakers. I need to power this unit efficiently. I have been reading about using Lipo batteries to power a fish finder so, I figured it could also be used to power a headunit as such. Does anyone have any insight on this?

General specifications
Operating voltage 10.2–16 VDC negative ground
Fuse rating 7.5 amp

Thanks,

Jared

http://www.fusionelectronics.com/marine/products/head-units-50-series/ms-ra50

 

You will be able to power it via a battery ....  one Big Battery   

Fish finders draw fairly little amperage.   Typically starting around 1/5  of an amp,  up to a little over 1/2 an amp.    The specs for that unit from your link gives no mention of minimal amp draw only that it needs a 10 amp fuse.  If your hoping to have a Party Barge Kayak allowing all around you to enjoy your tunes for hours on end,  it will surely take a battery many times larger than most of use are utilizing for our Fish Finders so to achieve even moderate listening levels. 

 For example,  a very efficient IC Tripath TA2021 digital stereo amp will draw in the ball park of 5 amps driving 4 ohm speakers at 25 watts per channel.

What kind of run time and volume levels are you hoping to achieve before hitting the battery charger


 

I wonder how blasting music into the water will affect the fish?

http://www.ebay.com/itm/Ballistic-Performance-Motorcycle-Battery-Dry-Lithium-12V-Volt-16-Cell-EVO-2-EVO2-/350848445587?pt=Motorcycles_Parts_Accessories&hash=item51b0326c93&vxp=mtr#ht_1325wt_1161


You can try something like this, I used a similar one on my boat. Hefty price to pay for tunes though. And you will have to keep it on a maintainer when not using it.

Did anyone else read "marine head" and think of something totally different?

I wonder how blasting music into the water will affect the fish?

Maybe somewhere out there you can download a recording for a school of bait fish / baitball.

Play it back and hope you don't see a big ring of air bubbles coming up from the depths around your kayak   


in relating to real world applications.... I think we have all seen the "Job Site Radio's" being sold by Makita, Dewalt ....     They can also run off of the batteries they charge but for how long I don't know.  I have been on several jobs where contractors are blasting music from them,  running strictly off a 18 volt battery pack. 
Back in my day,  Boom Boxes could provide hours of high volume listening running off 8 or so D batteries. 
 
Personally I would run a test setup before doing any cutting on the Kayak.   If you don't have one,  borrow a battery similar to what you would consider running and do a temp wire up.  Crank it up to near the volume levels you would hope for and see how long it lasts.   

I like to spend some time on the water with the family too. So when I am not fishing I would like to have some music. Here is more information.

Standby, Current Ignition OFF – 6mA
Standby, Current Ignition ON, Stereo OFF via power button – 6mA
Stereo ON, No volume 0.6A
Stereo ON, Average comfortable listening volume – 3A
Maximum Current Draw – 15A

If you have a 12 or 14 volt drill,  you could experiment with one of it's batteries to test for run times.    I have seen many get old, dead drill battery chargers, gut them so they now just act as a base to plug battery packs into to provide cordless power for other devices. 

I have also thought of installing speakers and even a Sub as a just for fun project.   

So... I been doing some more research.. If the unit will draw on average 3A, that is roughly 3000mAh. which will give me roughly 1 hour of play on a 11.1v 3000mAh lipo battery. So, If I was to take two 11.1v 6000mAh and put them into a parallel configuration, I would end up with a 11.1v 12000mAh pack. Which in theory would give me roughly 4 hours of constant playing. Of course this would be saying I was draining the battery 100% which I know not to do with a Lipo battery. Therefor, even at 80% I could still get a good 3.75 hours of play on this setup.  This setup would weight in at about 2.5lbs vs. 30+ lbs auto battery which would give me hours and hours of play. Weight isn't all the big of an issue either, my Yak is rated at 450lbs carrying load.

Did anyone else read "marine head" and think of something totally different?

YES!

I am somewhat confused when you state 11.1 volt battery vs. those typically declared as 12 volt versions.   Guessing you have been looking at those designed for the RC world
    If I am reading your numbers correctly,  you are essentially looking to double up with 2 batteries similar to these 68000 mAh Lithium-Ion backs which are kind of the starting point for use with fish finders or other low draw electronics.
 


Personally,  I would be looking at batteries rated in Ah vs mAh like this motorcycle battery.



Remember that you need a battery that can provide 3 amps of continuous current just to accommodate your lower volume listening levels besides when your favorite song comes on crying to be turned up much louder.   You may be getting close to it's 15 amp maximum draw rating at that point.   

Yeah. The 11.1v are designed for rc use. However at a full charge they are actually 12.6v. They are 3.7v per cell. I found some 12v 9000mAh batteries that belong in a UPC (battery backup units). I am thinking two of them or going with something like a small motorcycle style or 12v lawn battery which are both rated in the AH.