Thread: Powering your sonar off the boat.

I had a few people ask me how I power my sonar units while they are off the boat.

Let me back up a minute.
While talking to people at various fishing events this winter the conversation always turns to research in the winter. We talk about Google Earth, google maps, and Lake chips. We also talk about AutoChart on and off the water. Without getting into the whole conversation, most are curious as to how I power my sonar units while they are off the boat, say from the comfort of my recliner (which is where I am while typing this up). I also hook it up while in the mancave doing research, or working on man type stuff. lol

I made a power source from an old 12 volt power supply. I think it was used to power our old wireless router. I usually get the look. Like what the heck do you mean you use an old power source? And then the next question is always, HOW?

Simple.
Your sonar unit has power requirements. For this post I will use my HumminBird 899HD SI head unit.
Power requirements can be found in the owners manual. We all know they run off 12volt. Most AC/DC power supplies used for cell phones, wireless routers, laptops, kids games/toys, etc. provide 12volts.

The key question is how many amps does your sonar unit need to run (draw) and how many amps does the power supply provide? The sonar unit will only draw as many amps as it needs to operate. If your sonar unit needs 1 amp and your power supply provides 5 amps, it will work, provided it meets the voltage (12) requirements. If your power supply provides 1amp, it will still work.
See pictures below.
My 899 specifications as found in the owners manual, free download from HumminBird. I need 1 amp and 10-20volts.



My power supply OUTPUTS 12 and 1 amp.



As for hooking it up. Figure out which is positive and which is negative coming off the power supply. Generally the stripped wire is positive. Typically the red wire coming off the power lead for the sonar unit is positive, splice in a fuse and hook up positive to positive. The other two wires are neutral, splice them together. Plug it in. If you have the wiring reversed, the sonar unit won't power up. I think HB built in protection in case of reversed polarity connections to protect your investment, but don't quote me on that. A voltage tester is cheap compared to a new unit.
Picture of my wiring below.



Fire up the unit. Since I research specific lakes on my sonar unit. I install my map chip.
Set the unit to SIMULATION.
Scroll through the VIEWS until I get to a lake view.
MENU button twice, scroll to CHART, scroll through list to LAKE LIST, scroll through list until I find the lake I want to research and select it.

Image below is Sangchris Lake in Illinois. Our first Crappie tournament is there in 3 weeks.




Remember my sonar unit is in simulation mode. So all the displays are incorrect, time, temp, depth, speed, distance, bearing, are incorrect. But the lake map on screen is Sangchris. I can scroll around on the lake, zoom in, zoom out, find the creek channel, find likely spots to fish. Say I am looking for water 10-20' deep near a creek channel. Everything highlighted in green on the screen is water 10-20' deep. Everything in red is 5' or less. The dark blue is the creek channel.

IF I had created this map using AutoChart, I could overlay side imaging and see cover (trees, brushpiles, etc.) and structure (rocks, ledges, points, etc.) in that target area, 10-20' of water.

I'd be interested in hearing how others research lakes using their map chips.

One word of caution would add a fuse on positive side of power supply. A 3 amp fuse would protect the vast majority of units being made.

Don't ignore the fuse advice by OP.