This is a great tool to have around the home. It has some neat things built in to charge and recharge the battery. In the old style, they had switches that you had to adjust for the amperage of the battery. It has a built in microprocessor to read the battery charge and adjust accordingly. Another nice feature I like is that if you accidentally plug the wrong wire into the wrong post, the charger will stop so you don't ruin your battery. It's pretty easy to use. Just plug it into any 110V outlet, connect red to plus, black to minus and you're done.