Finned rectifier isolators, cotton cord tires with tubes and a floorboard starter button work well together. Most finned isolators use rectifiers with 50-volt ratings and reverse leakage through the diodes is atrocious new out of the box and only get worse until they fail. This includes the Sure Power blue anodized brand finned rectifier isolators. They are JUNK!
Using a hugely over-rated isolation relay is a wise alternative. A 200 amp rated isolator working in a 100 amp environment will last 5+ times as long as a 100 amp isolation relay. This is one area I heavily favor the use of automatic switching charge isolators.
