Let me start by saying that I installed this charger on April 27th a whole week ago. I haven't moved my car since, but my car has On BoardDiagnostics installed for State Farm. Leaving my car for a full week without starting and running triggers more than a few emails telling me the voltage is low. This hasn't happened and a trip to my State Farm site shows Green and OK on the battery. For me this is great news. It works out.