Lead is a heavy, non-radioactive metal that has been used in batteries for many decades. In fact, lead acid batteries are still widely used to run trolling motors, usually by connecting three 12V of those in a series. But there are newer and better options these days—particularly lithium iron phosphate batteries for trolling motor applications. And certain types — like the 36V LiFePO4 battery — has proven itself capable of powering a motor as efficiently as three 12V lead acid batteries.