fishfinder mounting

Cabelas has a battery and charger for fairly cheap.

link to the cabelas battery.

I have this, and it performs well.  I also have a frys battery and it is the same, just didn't come with a charger.

MolBasser

Sean,
I wish I could provide a photo of the install on my Prowler 15 but this may give you some more ideas.  My Humminbird Pirhana Max 15 came with a base mount that I installed on the sloped portion between my feet but I rotated the base 180 degrees to keep the profile as low as possible.  I initially thought that this would allow me to tilt the unit forward to allow hatch access but it turns out that is exactly where my butt needs to go.  So I remove the head from the mount to get at the hatch, no big deal.  The cables come through the hull under the base and loop out on the bottom side of it leaving enought slack the keep the cable routing casual and allow removal while remaining plugged in.
I got lots of advice from this site regarding the proper adhesive to mount the transducer inside the hull, even went to Ocean Kayak and it turns out that nothing bonds to polyethylene but Goop is the best thing available.  I had a piece of my hull that I had remove to install a hatch between my legs which I used to test lots of adhesives and nothing really bonds.
So far, my goal in adding goodies to my yak is to keep it as uncluttered as possible since I'm prone to clumsiness and can tangle up anything with hardly trying.
Good Luck.

Pete

You can read most FFs datasheets and see what kind of current they draw.   Humminbird doesn't list the power of their piranhas, but it did say that 8 AA batteris would last 60 hours with no backlight, and alkaline AAs run about 2800mAh - which implies the piranha only draws about 50mA.   The eagle fisheasy 2 draws 350mA, fisheasy 240 draws 170mA, and cuda 128 only draws 110mA according to their datasheets - depending on your choice you can get by with 1/3 the battery.

Ah ... so battery life is something I know a little about as I design portable video recorders for a living and I'm working on a project that runs off AA batteries.

You need to be careful with the mAH ratings.  I don't have the battery datasheets handy right now, but I'll give an example that comes to mind.  The Duracell AA Coppertops have a rating of 2850 mAH, but you need to be careful with how they measure that depending on how low the voltage drops  for that measurement.  At a current drain of 500 mA, you'll get about 3 hours before the battery drains to 1.0V. That means that if I have a device that can't run below 1.0V, I effectively get 1500 mAH (500x3).  It's somewhat non-linear depending on how much current you draw.  At 750 mA you get about 1125 mAH (or 1.5 hours) before the battery drops to 1.0V.  At 250 I think (not sure on this one) that you get ~7.5 hours before dropping to 1.0V.  I can look up the plots tomorrow when I get into work.

What does this mean?  Well, my Matrix 17 can run down to 10V.  With 8 AA batteries in series on a 250 mA drain, you'd be able to run 7.5 hours before the voltage drops to 8V ... too low to operate.  So in reality you get <7.5 hours before the voltage drops to levels that you wouldn't be able to run at.  I'm guessing you'd get ~4 hours before it drops to 10V, maybe a bit more as the voltage drops faster as it gets lower.  At any rate, you get the picture.  Note that in addition to battery performance changing depending on what mA you draw, battery performance also differs depending on what type of battery you use.  Also backlight makes a huge difference.  It is probably the single largest current drain on a system.  So I definitely can believe the 5-6 hours on a 3-4 Ah battery for a FF/GPS combo.

Hope I didn't bore y'all.

-Allen

Allen is right.  The good news is that a Matrix can run on up to 19V.  When I build my AA battery packs I use a 10 cell holder so I start out at 15V with regular batts or a full 12V with recharg batts.  They last quite a while, definitely at least 8-10 hours.

The famous Cabelas batt. is cheap, but it is also big.  It is a 7ah which is overkill for a ff.  They make AGM batteries that are half the weight that will still run a 250 ma ff for hours and save you 4 or 5 lbs. Something in the 2-4 ah size is plenty.  Try  http://www.batterymart.com for a good inexpensive assortment of AGM batts and chargers.  Straight to the 12v's...http://www.batterymart.com/battery.mv?c=sla-12volt

HELLO ALL I JUST BOUGHT A MATRIX 25 IN IWAS THINK ABOUT POWER THE   THE I LOOK AT MY 18 V DRILL AIN SAY WAIT A MIN THAT DRILL IS 18 VOTE I NEED 12 SO HOW ABOUT A IN LINE FUSE JUST IN CASE   DO I REALY WANT TO DO THIS
OH WELL.
I HOOK IT UP IN IT WORK WILL RUN SOME RUN TIME TEST WILL POST BACK
KAYAK TARPON 140 RUDDER
MARIN COUNTY
FISH BAY AREA SAN PABLO BAY

I have mine set up so the entire mount comes right off when I am not using it. It takes about 2 seconds to take off and about 3 to put on. I went to Home Depot and bought a 9'' x 9'' drainage grate, cut it to the size I wanted, then bolted the base to it. A short shock cord and 2 eye hooks keep it in place perfectly.
You can check it out by going to the 'Rigged Kayaks' section then "Mike's (TOTE) kayak trolling rig....". Mooch was kind enough to post a few pics of it. I also used the same grate concept for my downrigger. The material is impervious to the elements, even salt water, and is very easy to work with.
Tote

My setup is basically the same as Art's picture, only I have the battery in a tupperware, right underneath the wood and installed bungies to hold it in place.  The transducer is mounted inside and the cable comes through the hatch.

Josh,
You are the GHETTO king.  The jigs look sweet, but the leash needs an upgrade.

Stuart