I AGREE THAT OPTIMA BLUE TOPS ARE THE BEST. I DISAGREE THAT THEY ARE A GELL CELL. THEY ARE AGM. ADVANCED GLASS MAT. COMPLETELY DIFFERENT FROM A GELL CELL. IF YOU DECIDE ON GELL CELL, YOU MUST CHANGE THE SWITCHES ON YOUR CHARGER TO ACCOMODATE A GELL BATTERY. AGM SHOULD STILL USE THE LEAD ACID SETTING. GOOD LUCK.