KEVIN TATE The Old Man looked at the meter on the trolling motor and breathed a deep sigh. Our battery had just enough juice to lift the needle clear of the leftmost peg, at least, while the motor was off. Switched on, the needle hit bottom and the propeller turned a few sad and useless laps before oozing to a halt. The previous day had been windy, so we’d used the motor and its battery a great deal, sometimes without stopping for nearly a half hour at a time.