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'