very curious to hear what people say. I am running two 31 series on my 2008 Cougar FTD. At first I thought my batteries had gone bad because the light would show green but my batteries had very little juice. I hooked them up on manual charge and have not had any problems since. I thought their was a problem maybe with the on board charger. I have still not had a chance to bring in the boat to have the charger tested and looked at.