be huge to a small boat owner who doesn't have an inverter on board! I can see the drill sitting, unused for a year, then something brakes and needs fixing on the run. Here you are under sail in rough seas and you find out two of the four rivits that are holding your goose neck have fallen out. The threads are stripped out. You have the two bolts you would need but the battery in the drill is dead. A storm is coming and your wife called on the cell phone that the house next door is on fire threatening to make the jump over to yours. Also she said your dog is dying. Man, you really need to get home and you have a dead drill battery! Why didn't you buy the one that you could plug into 12 volts that would have saved your sorry ass? That would have been me I was talking to of course.