I have a Bass Buddy for a fishing boat and I love it.  I run a 34lb Minn Kota trolling motor on it.  I need a fish finder on my boat ,but can I run the trolling motor and fish finder on the same batterie.  the batterie is a Batterie Plus multi-purpose, marine starting, Deep cycle batterie.  or do I need another batterie.  Keep in mind my boat is only 8feet long I need all the space I can get.  I also fish about 6 hours or less at times.  Please help!

The only problem that you may experience would be the possability of electrical interference when you engage the trolling motor. If you have an analog motor, it will have a higher chance of this happening, but doesn't mean that it will. The amount of draw that a LCD will place on your battery will be small. (Less than 1 amp)

Should not be a problem, however the time spent on the water may run the battery down running both equipment. This may also be good, I find that running my batteries down then charging lenghthen the life off the battery.

cabelas sells a small rechargeable deep cycle battery, but think about a portable fishfinder,i fished out of a similar boat for years,the lakes were relatively shallow,i found a fishfinder useless because of the narrow cone angle