So I went ahead and purchased a Battery Tender Junior to keep the battery charged over winter. The instructions for connecting the battery tender with the battery installed are to connect the positive clip to positive battery terminal and the the negative to the chassis or engine block and the plug in to wall socket. My question is will I be doing any harm with the negative connected to the negative terminal of the battery? I installed it after the car was parked so access to engine and battery is limited and this was the only connection I could see and reach. I am trying to avoid pulling the car out of the garage but will if I am doing any harm with the way it's connected now. Any help is appreciated. Thanks.