I purchased two units to maintain the batteries in my motorcycle, home backup generator, lawn tractor and tractor. The provided cables with the 2 units made it possible to set up "permanent" connections to each of them. All that I need to do is to plug the chargers into the units that are not in operation and everything stays charged full-time. After about 10 days of constant use, one of the units failed. I contacted the company, and they very quickly sent a replacement. Any electronic device can fail, and I appreciate the company's quick and courteous response to my problem.