The boat's "fuel tank" is 16 AGM (absorbed glass mat) 12-volt batteries wired to generate 48 volts with a total of 400 amphours. The batteries are in continual use, balancing incoming current with outgoing electrical needs. These batteries have a 500-cycle span. That means you can deplete one battery 500 times, drain it halfway 1,000 times, or anything in between the two. Then it's off to a certified recycling facility. Better batteries are on the way. The boat's builder plans to install smaller, lighter, lithium-ion batteries that have a lifespan of 2,000 cycles and double the amphours.