JEM Watercraft

Where would it be best to make or attach a battery compartment for my fishfinder? Should it be watertight? The battery is 12v.

Find the best spot where it doesn't impact the trim of the boat.

Hi Louis,

I use a small, closed cell motorcycle battery. Only weighs about a kilo or so and just put it somewhere out of the way.

BTW, I have also used a 12 volt battery drill battery and that works very well.

Thanks guys, so I guess that means no special considerations.

You got me thinking Mick. I had a 12-volt motorcycle battery in my mind also. However now that you mention it, 12-volt power tool batteries (NiCd) would do much better because they are built for what is called "deep discharge" whereas the motorcycle (car) batteries don't like being discharged. On the other hand, Cd in the water is NOT a good idea. Think tupperware!

Get yourself a water-tight container for the battery and then just strap that in place somewhere.

Easier and less obtrusive than building a box as part of the boat.

If you aren't using a sealed battery then I would suggest some form of ventilation for the case or it might get explosive from the fumes discharged from the battery when you open the container near a spark.

Chuck

Hairymick, how would you suggest hooking up a 12-V power tool battery? Wouldn't you have to have the fish finder power connector mate with the battery, and still take it out to charge it? Any photos? Thanks

Hi MK,

I cut the positice power wire and inserted an inline fuse holder.

I crimped a spade terminal on he end of each wire leading to the terminal and, being careful to align the positive wire with the positive outlet of the battery held them in place with one of the plasticspring clamps I use to build my boats.

Some power tool batteries connections have a gap between the connection points and the battery body. On these, the spade bits can simply be inserted into the caps

I will try to get a piccie or two tomorrow mate.

There are also sealed 12V batteries that are used in buildings for emergency lights. These batteries are lead acid but, are completely sealed and won't spill. They only weigh a couple pounds and that could be another option as well. The ones we have in our office are 7 amp hour.

Hey Surfman, those sound like deer feeder batteries. Might be the way to go. MK