I just received a Humminbird PiranhaMAX 220 for Christmas. Okay, I bought it, handed it to my wife and said, "Here, wrap this." On Christmas Day, she handed it back, unwrapped! Anyway, I know that there are various options available for power, from a slew of AA cells to lantern cells to motorcycle batteries. Each have their advantages and drawbacks. For you guys who have already tricked your yaks, what do you use for power and why? I'm leaning toward the motorcycle battery since I have a good enough charger, but I don't want acid everywhere if I get upsot. Thanks, and Happy New Year!