It is just as it says. It is a battery maintainer. And yes you have to have power to it from the MH. I had the wire already ran on my MH. I pulled a dolly and had to have a hot wire to keep the battery up on the dolly. Just tied into that wire. You can get these at amazon on sell for 20 $. They work good.
2008 Gulf Stream BT Cruiser
Wisdom is not a product of schooling, but of a lifelong attempt to acquire it.