Floating Power Supply
Submitted by coosbayyaker
A forum thread discussing this article is here.
I saw this article http://www.norcalkayakanglers.com/index.php?page=19 even before I bought my fish finder. I figured this would be the best way to go for a Kayak setup. So the idea comes from there, I just tried to do it with some stuff I had around the garage already.
The bonus that I didn't even think about when I put it together is that it floats.
I started out with a cheap container that is pictured in the first pic and soon decided it was not up to the job. Luckily I managed to find some Lock&Lock containers like in the original article, they are very nice and if you can find them, there a good way to go. I'm sure a good Tupperware or Rubbermaid container would work just fine.
Parts List
Container (5inch square is perfect)
10 2000 MAH or higher AA batteries
8 Battery holder w/9 Volt type plug
2 Battery holder w/9 Volt type plug
2 9 volt type plugs
Shrink wrap
Rubber Grommet
yellow butt connector or similar tube that fits grommet tight
Fuse holder (I used the one that came with the fish finder)
a little padding of your choice
a couple paper towels
NOTE: disregard container and foam in first pic:
Below is the nice Lock&Lock container with a rubber gasket and four latches. Very sturdy construction.
I got all the electrical parts at Radio Shack. I couldn't find a ten batterry holder so I used the two holders. I glued the holders together with 6 minute epoxy. I used the type with the 9 volt type connectors.You could use the ones without connectors and just solder the wire to the proper terminals. Would save a bit of weight. I thought it was cool with the plugs.
While the epoxy is setting on the battery holders, you can prepare the container. Cut one bell off the yellow butt connector if you are using one It's a good length..Drill a proper size hole in the top of the container to fit the grommet and make a nice snug fit for the tube you are using.Push the grommet in the hole and slide the tube in. If you drill a nice snug hole no silicone should be needed here:
Now go back to the now dry battery holder. I love that 6 minute epoxy!! connect the two plugs to the battery holder. Now cut one RED WIRE and one BLACK WIRE short to directly connect to eachother wiring the holders together in series. Slide a piece of shrink wrap over one end of the wire and solder the two together. Slide the shrink over the bare wire and shrink with heat.
Now you have your RED and your black wire for power. Strip the red wire and one end of the fuse holder.slide a small piece of shrink wrap over one end and solder the wires together. Shrink wrap as before.
Now push the wires up through the tube. Pull them out through an extra inch.Use some goop or other silicone and dab some where the wires come out, pull the wires back a bit and dab some more silicone until the tube is full of silicon. Let dry for 24 hours at this step so you get a good seal.
Put a couple folded up paper towels in the bottom of the container.It will soak any moisture that may develop in the container and make a snug fit for the batteries so the wont slide around. I also use a small piece os bubble wrap to cushion the top and complete the snug fit. Load up the batteries and make sure you have a fuse in the holder. Put the lid on and do a test float.....There ya go..12 volt power to go and it floats. I had no idea it would float but it's pretty cool. For the connections to the fish finder im just gonna use two waterproof bullet connectors and a little dialectric grease.
NOTE: When I mount my transducer im gonna glue a large enough piece of foam to cut a square behind the transducer to fit the container tight so it doesn't slide around.
Hope you enjoyed this how-to. You could make it with a 4X4 container, but I Idont think it would float..