Seaslug,
Yes, I have a dedicated/separate 4ah 12volt battery I use for my Fish Finder. That's a really handy feature on your FF that allows you to set an alarm for low supply voltage, very very nice. Also, Thanks for letting me know about the memory clarification. I'm going to look into it in detail with a few of the manufacturers and make what corrections are necessary for accuracy. Again,
THANK YOU! 
Perry