Fish finder

Looking for recommendations for a fish finder or my sea kayak.  Well, actually I see plenty of small units, but not sure how to deal with the battery issue. Also thinking that some kind of solar recharger might be useful if the battery is small.

Ideas?

Tia,

-Steve

Most 800w grey screen fish finders can be powered for 12-14 hours on 8 AA batteries.  More powerful units with GPS or color screens greatly reduce the run time on AA batts.   I use a 7.2Ah 12v that will power my Eagle Cuda 350 FF+GPS and LED lights for 40+ hours on a charge.  Haven't played much with solar stuff, but I imagine it would greatly extend battery life.

 

  Solar would be a nice thing, however, keep in mind that the solar panel would have to supply enough current to replace the load (Current draw from everything connected to what ever battery you choose)If the load on the battery is greater than the solar panels output, sadly the battery won't charge. (Until the load is shut off)
  The size of a panel that will be big enough to power a FF, you'll need one that can supply about 1amp (1000ma)of current or around 12-15 watts.  The physical size of a 15 watt panel is not that big, but to have it mounted on a kayak, it'll take up some space.
  Back at camp on the other hand, you could set up a large (Regular size) say 60 watt panel (Unregulated voltage of around 19vdv ) would supply about 3 amps of current in direct sun, that would be enough supply a charge on a typcal 7ah gel cell.
P=V*I P=power in watts, V= voltage, and I=Current in amps

Careful with charging those SLA batteries, especially from unregulated sources.  They will charge, but you're likely to decrease battery life.  SLA's should be charged with constant voltage and at a charge current of about 1/10 the total capacity.  That means if you have a 7Ah battery, you should charge at 0.7A source.  Constant voltage impies auto-shutoff as well since when the battery approaches fully charged, the current source will decrease, until the battery is fully charged and the current is shut off completely.

-Allen

Excellent info, thanks all. Where did you get the battery pack? Looking for a part #

I use a standard sealed 12v 7.5AH sealed lead acid (SLA) battery commonly used for alarm systems.  You can find them pretty much anywhere.

http://www.batterysharks.com/Casil-CA1270-p/CA1270_B12-7.htm?gclid=CK7E25reha0CFcoaQgodQ0IVRg

Google:
12v SLA battery

Most auto parts stores carry the SLA batteries at a cost of around 20  - 25 bucks. Then get a small trickle charger like Allen pointed out. Another 20-25 bucks. So much less hassle than smaller battery systems. Weight? 5 lbs. Ocean Kayak makes  a battery bag you can mount in various locations in the kayak.

Awesome replies all, thank-you so much!  Hope to see you out there, Happy Holidays.

Kayakfishingsupplies.com has a good selection of batteries.

http://www.kayakfishingsupplies.com/servlet/the-364/12v-7-Amp-kayak/Detail

SLA battery velcro mounted in the front hatch is the best way to go... Most reliable... Don't forget to put an inline fuse on that bad boy!!!!

If you are close to a computer supply check out replacement UPS(uninterrupted power supply) batteries,motorcycle batteries, electric scooter,etc.

A crude formula for battery life, divide the battery size by the FF power draw for hours of use.
Example  7amp battery=7000mah, FF power draw 350mah,   7000/350=20hrs

What size inline fuse is reccomended?

What size inline fuse is reccomended?

 Most FF ask for a 3amp fuse to be installed.... as close to the battery as possable.

Thanks FishBucket.  This forum beats reading the manual.

So I spent a little money and tricked the yak.  Fish finder and rod holder, power source .  I have a list of every part I used and it was quite easy to DIY with some guidance. Should I post pics, steps, and parts on my experience or is there plenty here?

I was going to attach a pic, but it won't work on this site with  iPad, will do so when I get back to a desktop.