Need help with Fishfinder

Sunfish,   

If your battery shopping and anywhere near the Beaverton area,  I can get you batteries for around 1/2 that of retail sources.   We use them a great bit in my industry and I have a distributor down that way.
http://www.tri-ed.com/BranchLocation.aspx?id=298

thanks. 
Possibly this Thursday I will stop by with my many questions.

If you have questions regarding battery info and how they will relate to fish finders, they will just give you blank stares in return. 
If you know you will be by there, I can call and let them know I have someone coming by.   Being that they are a distributor of security and CCTV systems, they only deal with authorized contractors and not consumers.   You could make up your mind which battery you want when there and pay at the counter.  Just PM me if I can help you out.

I have the Eagle Cuda 350 S/Map which is basically the B/W version of the Lowrance.   Specification wise it draws the same.   I am using a small 12v 2.4ah battery and have ran 3 consecutive 8 hour days with no problem.   This is without utilizing the back light which will reduce the run time a good bit.  Since I doubt I will ever be out more than 2 days without means of recharging, I want to keep the weight to a minimum.   

I have a Eagle Cuda 350 FF.

How is that working out for you? I am targeting that FF for my my yak, and am interested in hearing pluses and minuses.

Sherm So far so good. I have not used it much yet and have just scratched the surface of what it can do. I like the features that it has, it gives you a very good picture of bottom structure. When I was using it yesterday I noticed that I could tell where the edge of a weed bed was and the hard bottom.  It worked well for trolling along the edge of the weed bed without getting fouled up on millfoil. The screen is very clear. I have not used it yet on gps so I cant say as to how good the internal maps are. Jammer has the same FF as I do and he has way more hours on it than I do. Drop him a line and I am sure he will be a wealth of information.  If you want to check mine out before you buy one let me know and we can get together and you can check it out PM me if you want to set something up.

To determine the theoretical battery life you need to know the power draw of the M68C.  Your battery system will be rated in amp-hours (aH) and the power draw in milliamps (mA).  Convert milliamps to amps and divide amp-hours by amps to yield hours.  Then expect something less.

If you are a camper and traveler who will be taking multi-day trips in which you will be separated from a power source for recharging, the AA battery systems could keep your system going for as many days as you need given enough fresh batteries.  You may also consider getting an inverter to charge your kayak battery from your vehicle. 

thanks for all the replies and advices.  I am leaning towards the Cuda300 or the 350.  I like the idea of the AA battery pack.   And for my 1st FF, thought it was wise to not spend too much.   

CraigVM62,  thanks for the offer.  I'm still doing research and will be away this weekend.  I'll pm your if I decide to go with a single battery vs the AA battery pack.   

I am trying to learn everything I can, and appreciates all the responds.   
 

 

Who is going to be the first to try a Lipo battery    

Sun here is a cool link for you. On the eagle web site they have product emulators. You can download a active simulator to your laptop and manipulate any and all setting on their FF. They don't have the 350s but they do have the 240S/gps which is almost identical to the 350 cuda in function. I downloaded it to my laptop so I can learn all the setting while sitting in my recliner in my livingroom. Here is the link. http://www.eaglenav.com/Downloads/Product-Emulators/

thanks for all the replies and advices.  I am leaning towards the Cuda300 or the 350.  I like the idea of the AA battery pack.   And for my 1st FF, thought it was wise to not spend too much.   

CraigVM62,  thanks for the offer.  I'm still doing research and will be away this weekend.  I'll pm your if I decide to go with a single battery vs the AA battery pack.   

I am trying to learn everything I can, and appreciates all the responds.   
 

While I was up at NAVSTA EVERETT for meetings I stopped by a battery store on my way to I-5 and picked up a 12ah battery for my HB 597.  My digital charger brought it up to 100% and I began testing.  I quit after three total hours and measured voltage drop at one tenth of a volt.  Think it will do just fine.  Good thing too as it barely fits in the T-13's battery bag!  LOL.

The 597 has a 615 mA draw.  You're not going to see appreciable voltage drop on a 12 aH battery after only 3 hours.  Battery voltage drop is a non-linear function over time.  It will remain relatively flat for almost the rated time, then drop sharply after that.

Battery ratings are not consistent.  The rated time on a battery assumes a particular current draw.  You draw anything other than that and you can have shorter or longer battery life.  The rated time on a battery also assumes a particular voltage drop.  The rated time on a battery also changes over lifespan, and that also depends on usage and charging scenarios.  Bottom line, plan to get 50% of the rated time on a batter and be happy if/when you get more.

-Allen

This setup has worked for me for years; in and out of the surf, stored out in the sun, etc. Burned out a couple fishfinders but the transducer is still good and so is the battery.
AA batteries may be more convenient, but they won't last as long as a lead acid battery. The 1.3 amp battery I use lasts about eight hours.
Not a big fan of expensive fishfinders. Like computer hard drives, they all die eventually, dunking them in salt water probably doesn't prolong their life either. Give me an inexpensive fishfinder that locates fish(I've had good luck with Eagle, not so much with Hummingbird) and a handheld GPS instead of a combo unit.

thanks for all the replies and advices.  I am leaning towards the Cuda300 or the 350.  I like the idea of the AA battery pack.   And for my 1st FF, thought it was wise to not spend too much.   

CraigVM62,  thanks for the offer.  I'm still doing research and will be away this weekend.  I'll pm your if I decide to go with a single battery vs the AA battery pack.   

I am trying to learn everything I can, and appreciates all the responds.   

I use the Cuda 300 and love it.  I also have a separate handheld GPS though like ronbo just mentioned.  I would suggest checking out Fry's in Wilsonville for batteries if you get a chance.  They have many different sizes of sealed lead acid batteries in stock as well as NiMH AA's.  Browse their website and call ahead if you're looking for something specific.  They also, sometimes, have the 8 cell AA holders but they rarely have the 9V snap connectors you need to connect the battery pack to the wires of your sounder.  I have easy access to the cell holders and 9V snap connectors though so let me know if you can't find them.

Another thing I wanted to add about rechargeable batteries, expanding on what polepole said eariler, is that different chemical compositions have different charge curves.  Here's what the charge curve of a lead acid battery looks like:



This is nice because you can just remember a couple of points and if your sounder shows you the current voltage of your battery, you know about how much charge you have left.

This is what a NiMH cell's charge curve looks like: (U means voltage and %C means percent remaining of a full charge)



This may look like it would be tough to determine how much charge you have left by knowing what voltage you're at, but I've been using NiMH AA cells for a while now and after seeing how the voltage level drops on your sounder a couple of times, you can get a feel for how much charge you have left.  Like polepole mentioned, the drop is not linear, but with NiMH batteries throughout most of the discharge, it's close enough until you get to the end. 

And why are you all using 8 AA batteries?  That's fine for Alkaline batteries which are 1.5V each, or 8*1.5=12V in total.  But for NiMH batteries which are 1.25V each, that's only 10V.   You should be using 10 batteries to get 12V.  This will be fine if you use Alkalines in a pinch because most FF can run in excess of 15V (check your first before doing so).

Note that AA batteries are specified at a capacity under 500mA drain.  So if you're using a FF that draws more (like a 597 with high res screen, colored screen, and GPS), your mileage may vary.

Jeff, what do you do that enables you to nerd out with me on batteries?   

-Allen

Jeff, what do you do that enables you to nerd out with me on batteries?   

HAHA!! I'd better be learning something that applies to kayak fishing in my electrical engineering classes or else what the hell good are they? 

Using 8 AA's is actually better for lower drain sounders(like the Cuda 300) while only doing one-day outings here and there IMO.  True, with the NiMH batteries you only get a nominal voltage of 1.25 through out the discharge.  When I fire my sounder up after a fresh charge I'm getting somewhere in the neighborhood of 10.8 volts.  The important thing with NiMH cells is you do not want to over-discharge them past 1.1 volts(polarity reversal is a bad thing).  That means at 8.8 volts, you want your sounder to shut down.  My Cuda 300's cutoff voltage is somewhere around 7 volts so even at 8 volts it'll still run just fine.  One can set the low battery alarm to sound at 9V and shut it down after it dips below that.  I can easily get two trips out of my 8 AA setup and that's really all I need for most of the year.  For long trips I bust out the SLA battery.  NiMH are cheap, light weight and easy to find. 

Alkaline batteries do say they are 1.5 volts, but that's their full charge voltage - their nominal voltage under load is actually around 1.3 or something.  They are better for low-drain, intermittent use because they hold their voltage very well when not in use.

I used a 10 pack of rechargable AA's in a pelican box for years.  I loved it but I could only get 1 trip per charge.  Finally found a good source of cheap 7ah lead acids this year and haven't looked back.  I've managed 3 trips on a charge and had plenty of juice to spare. 

When it comes to chargers, shop around.  I found a huge range of both prices and features.  Finally settled on a motorcyle/ATV charger from Ace Hardware.  It's a floating charger that does a diagnostic on cell condition before charging.  According to the docs, the charger re-conditions bad cells when required.  What does that mean?  I don't know.  But, it was only $18.99 and I don't have to unplug it when it's done charging. 

-Spot-

But, it was only $18.99 and I don't have to unplug it when it's done charging. 

Umm... where can I buy this magical device?!  That's a deal!  EDIT: oh, you said it in your post... thank you. D'oh!

Good point.  With SLA batteries, you want a charger that is specifically made for SLA batteries if you want to get the longest possible life out of the battery.  I learned that the hard way.   

Jeff, what do you do that enables you to nerd out with me on batteries?   

HAHA!! I'd better be learning something that applies to kayak fishing in my electrical engineering classes or else what the hell good are they? 

That explains it.  I'm an electrical engineer myself and have had to deal with battery usage and charging scenarios on the job.

-Allen