Hmm, that's interesting. If that is the case then all those small solar chargers are not a good idea. And the California Emissions Control (CEC) ProMariner chargers serve a purpose beyond cutting emissions, as they have shorter run times.The whole point is not the charger, but exercising the batteries. Continuous small charge currents to replace natural discharge are reported to allow for some sulfating. (I guess a stronger current is needed to combat sulfation) To be truthful I have never been able to tell the difference but like I said we use the boat frequently enough that it would not come into play. Know some folks that run the charger 24/7 for a few month at a time and they have no complaints. Do not know at what length of time the effect would significantly affect battery performance. For me I personally value convenience over $$(battery life); if it is inconvenient to cycle the charger I would leave them charging 24/7.