Sonar power question...

I am looking to instal a new sonar unit in the bow of my boat. I don't want to run the power to my main battery out of concern that it will put an undue drain on it (I already have one unit running to it). I have an aux. battery I use for my trolling motor, but again i don't want to prematurely drain it as the day goes on. Since space is at a premium in my small boat I am wanting know if anyone knows of a small battery that could be used to operate a sonar unit, preferably rechargeable.

Thanks

Keep on chuckin'

Putting another sonar unit on your cranking battery should not drain it enough for you to notice over a day's fishing.

Dave is correct. You will not pull enough with the second sonar to cause you to run down your cranking battery.

Tight Lines

I've been using a small sealed, rechargable battery that is made to power one of those toy jeeps that kids drive around in. It works great and is about 1/4 the size (or smaller) of a car battery. Can go several days without charging, no acid to spill, etc... If you want an independent power suply look into it. Or you could just use two lantern batteries, they'll run a fishfinder for several days as well, but get expensive.

I purchased a battery that sounds much like you described with a charger in Cabelas for about $20. I picked it up to be able to take my sonar up to Canada and mount it portably on what-ever boat we ended up in while portaging. Worked great and as you said would run the battery for several days.

kc

Yeah, you definitely do not want to connect it to your trolling battery/batteries because it will cause a voltage drop that will effect the display, when cranking full throttle. The starting battery is fine, as the other 2 guys stated. The boat I just bought was wired that way and I need to rewire to the starting battery.