Im looking for a light weight 12volt battery?

You need to select a battery that meets the specifications of the trolling motor. A deep cycle battery is the appropriate type for steady long term use. You also need to match the the amps per hour requirements. Many of the light weight batteries are made for automotive starting. They provide a high current for very short periods of time, cranking the engine. Then are recharged. They would not be appropriate for trolling motors of boat house batteries.

I understand your question, but the amount of power required is at a "cross purpose", Lighter batteries are available but cost several times that of the one you have. Smaller "lead acid" wet cell batteries will not provide the power you need. It's just a matter of Physics. The charge available is determined in part by the weight of the lead of each plate, thus each cell is heavier......this also improves how quickly the battery recharges. I don't know how a "gel-cell" would work, and very high tech battery( s) run several hundred dollars. If you are now using a group 27 battery it's a good choice. If you go to a group 24, it would reduce the power available by about 40%.

aircraft battery.

Group 27 or 37