powering a fishfinder up north...

I just got a little Garmin 90 to put in a 14ft Lund that does not yet have batteries/electronics. I'm going to use it in Northern Ontario where I will have no electricity and where the battery will have to stay through freezing winters without charging. I am hoping the charging cables on a new 15 horse honda 4-stroke will be enough to charge a battery? If not, are solar panel chargers the only other option? Do they make gel marine batteries that survive freezing? And is there a very small battery that can do all of this? Space is at a premium and the fishfinder shouldn't take much current.

I have never run any electronics in my boats, so I am pretty much new to most of the technology. Any help would be really appreciated

Re: powering a fishfinder up north...

the pwcJetSki battery would probably be fine use to have a 6hp honda on a sail boat, that maintained the battery fine. as far as lasting all winter without charging, i don't think you will find one, they need a float charger to maintain them. why not bring it home.

Re: powering a fishfinder up north...

thanks for the reply. How many ah (amp hours?) should I look for? Could I get away with very few if the motor is charging the battery for a couple hours a day anyways? Will I need anything more than the wires that came with my motor to charge it?

Also, do you guys recommend lead acid or gel or what for this application, and is there any sort of housing I will need for the battery?

Sorry for all of the questions...im still a little clueless and I'll be out of luck if i get all the way up there missing a part...

Re: powering a fishfinder up north...

Is the Honda electric start? The reason I ask is that would determine how large the battery needs to be. If is rope start but with a charging system, the wires from the engine simply attach to the battery and by all means OBSERVE POLARITY. Any home improvement store, auto parts store, or farm store carries garden tractor batteries. These run from 175 to about 350 cold cranking amps (CCA). A 175 or 250 CCA will do nicely and your engine will have no trouble keeping it charged if you make a fairly long run now and then. If you attach alligator clips to your locator wires you will be all set. I use a garden tractor battery to run lights, a fan and my locator in my ice fishing house. If you plan to leave the battery over the winter, either bring it home with you, or a small solar panel can be used to keep it topped off. They are available for less than $20 bucks. I have one in my shed to keep my garden tractor battery alive. Works well and the small ones don't need a controller as the output is so low.

Re: powering a fishfinder up north...

The motor is rope start but it came with charging cables.

What is the difference between a law mower battery and a small marine battery? I was just reading that some of the kayaking guys use 12v 5ah-7ah sealed marine lead acid batteries (http://shopping.microbattery.com/s.nl/it.A/id.6431/.f?sc=2&category=622 ) for their finders but I am really not sure if 5ah is the right size, or how that would correlate to CCA's.

Thanks for all the help and thanks for the solar panel trickle idea! would that work with lead acid and gel? I thought gel was more resistant to freezing...

Re: powering a fishfinder up north...

A five AH battery is about the size of four packs of cigarettes placed back to back. Kayakers use gel cells or sealed batteries because they can get upside down and flooded battery would spill its contents and the also have weight and space considerations.. In my view, that battery is too small for any sustained fishing. Look at it this way -- if your locator used 1 amp of current per hour, the battery would not last five hours. A marine battery is built slightly different than a conventional car or garden tractor battery as it needs to withstand more vibration and pounding. A marine "deep cycle" battery would be even better in your application as they are designed to deliver a smaller amount of current over a longer time and withstand deep discharging better than conventional or marine starting batteries. In your situation here's what I would do. Garden tractor batteries are about half the size of a car battery. They are also less than $20 at any farm store. I'd buy two of them and one solar panel. Put the solar panel in a window that gets lots of sunlight. Put one battery on the solar panel and the other in the boat. Swap the batteries every two or threee days days.

Re: powering a fishfinder up north...

The Garmin 90 says it uses 3.5 watts max and has a nominal of 12V @ 0.15 Amps. Does this mean that a 5ah battery would last (ideally) more than 36 hours on a single charge, plus whatever the honda is putting out (more than 0.15 amps?)?

Thank you very much for the info on different battery types. I did not know there was a difference.

Re: powering a fishfinder up north...

Yes it would. However, if you look at the battery specs, they usually have a maximum charge rate which is about 1.5 Amps. The engine will very likely cook (overcharge)the battery in a very short time. I'm wondering why you are so concerned about the physical size of the battery. If the locator only draws .15A, a garden tractor battery would probably run it all summer without charging. You can also buy the small gel cell batteries in much larger capacities if you indeed have some sort of size restriction we don't know about. The larger the capacity the higher the charge rate it will tolerate. I suspect the charge rate on the engine is about 6A and it's very likely unregulated which also presents a charging issue for certain batteries. I stand by the $20 garden tractor battery.

Re: powering a fishfinder up north...

Hmm...the lawn tractor battery is starting to look pretty good...

It just seemed like overkill when a tiny 5ah would run that long, and I'd rather not carry a heavier battery back and forth every year.

Is there any way to add a regulator to what the motor is putting out? Would it overcharge the lawn tractor eventually if the honda charges it much faster than the finder uncharges?

again, thanks for your help

Re: powering a fishfinder up north...

I've had a number of lawn tractors and none of them overcharged the battery and the system is not regulated nor would I expect your outboard to overcharge it. I made a box for the battery I use for ice fishing. The box is 10 inches wide, 9 inches high, and 7 inches wide so the 275 CCA battery iteself is 1-1/2 inches less in width and length and only about 5-1/2 inches high. They weight probably 10 pounds so this is not a big package. Again, the inexpensive solar panel would keep it topped off during the winter months. In fact I went out this morning and my tractor popped off like it was summer. It hasn't been run since last fall and has been on a solar panel since then. By the way, a charged battery will not freeze. If they did every car in the northern tier of states would need a new battery every day throughout the winter if the car sat outside overnight.

Re: powering a fishfinder up north...

What about a battery for a wheelchair. My brother in law used one of those in his kid's battery powered jeep. It worked very well and lasted a long time. I don't think it would like to be frozen, but most batteries will not last through a winter.

Re: powering a fishfinder up north...

Howdy from Canada!

testy...

Good advise from Silvertip! Sounds like you have much the same set-up that I do on my little 13-ft aluminum. I too have a 15/hp Honda (mid-90's), except mine didn't come with the charge-kit. I found one on ebay and am about to install it on my engine to run my fish-finder AND a Mincota elec/trolling motor.

Depending on which year your engine is, it could have either a 6/amp or a 10/amp charger on it. If it's only a 6, you may be able to upgrade to a 10/amp if you choose. Possibly you could hook an ammeter up to see what amperage yours is putting out.


I run a Trojan RV/deep cycle battery which I previously charged almost every day with a generator while at the lake. The charger will somewhat reduce the amount of generator charging I need to do.

You certainly won't use that much juice to run a small fish-finder so you'd do well with a more compact battery.

Good luck with your set-up and fishin'...

Cheers,
Terry

Re: powering a fishfinder up north...

Vexilar batteries might be a viable option for you. They weigh about 5 lb, They are gell packs and sealed so they wont spill and will run a flasher for 16 hours so it will probably run a LCD fish finder for 30 plus hours. Here is a link
http://www.vexilar.com/products/power.html

Re: powering a fishfinder up north...

another (cheap) option would be to use 2 6V alkaline lantern batteries jumped together in series to make 12V .... I would think they'd run a fishfinder for a long time.