The professional battery charger and maintainer has all the features that you need, whether you are a pro or a beginner. Just connect the clamps to the battery terminal. The reverse polarity alarm will alert you when there is an improper connection. Once connected, the bench battery charger automatically does the rest for optimum performance. Fully automatic high frequency charging delivers 5 stage charging, automatically switching from fast charge, to top-off, to trickle charge. Multiple protection + pulse repair, let you quickly start your machines.