Remember that 24v pulls equally from both batteries. Whatever you run down on the one battery will not be made up by the other. Your TM will only run until one battery is dead, then its done. So running down one battery with electronics and livewell pumps is not good on your system. A better idea would be to get a dual purpose battery for your starting battery, with around 100ah in a 27 dual purpose there is little chance of running it down to where your motor wont start. Ive ran mine on electric only lakes for a week, then started the motor just fine.