Fish come in all kinds of sizes, so why can't your battery chargers? Minn Kota attempts to solve that problem with four new on-board chargers, from heavy demands to light duty. Match the chargers to meet your power management needs. Output ranges from 6 to 30 amps depending on your wants, but all chargers carry a three-year warranty. Prices start at $109.99 for a MK 210 with 10 amps total output, with a $259.99 price for a MK 330 with 30 amps of total output.