I know the starting battery is not designed for use with trolling motors or other uses that draw the battery down, however, my situation makes this setup desireable. Am I asking for trouble? Here are the details:

I have a 24 volt trolling motor setup but rarely use the 24 volts. My motor runs exclusively on 12 volts (low) and offers adequate power. Occassionally, I use high which kicks it into 24 volts. Since space is limited, I am drawing off a large deep cycle for my 12 volt needs and when i need 24, I tap into the adjacent 12 volt starting battery (plus the deep cycle).

Will I damage the starting battery? I don' t draw on it for extended periods of time.

I' m no expert, but from what I' ve seen, a car battery is not meant to be drawn down and recharged all the time like a deep cycle batt. I think this is the biggest difference in the two types of batteries.

I' ve been using car battery' s to run my trolling motor for over 10 years I just got my 2nd battery. I also have a small boat but I still drain the battery down all the time and recharge it NO PRBLEMS here.

I' m not real sure of your type of problem so maybe some one else can be of more help.

Your definetely going to be disappointed teal. If space is a problem they make deep cycle in different sizes.

we got a new marine starting battery for our mariner. We thaught that the old starting battery would be good for the trolling motor in the canoe. We were wrong and at its highest speed the motor did not push the canoe. so now i just take the trolling motor battery out of the big boat when we need it for the canoe. so to answere your question, a car battery will probably be worse than a marine starting battery, which did not prove to be effective

They make a dual purpose starting and deep cycle that would be the way to go. Anyone useing a car battery for deep cycle is pretty lucky if it lasts four of five cycles. I tried them at first before I knew what I was doing. Niether of them lasted three months.