Minn Kota 315 d 3 bank charger .. #1 and 3 banks go green light saying the batteries are charged the # 2 bank stays yellow then goes to yellow with a red light .. I can then swap the charger leads with the # 1 bank and battery with the # 2 bank and battery within a few minutes the #2 and # 3 will go geen light and the #1 bank stays yellow then finally goes red and yellow this sounds confusion but the problem is changeing batteries when I swap the leads can any one make any sense of this and tell me what's going on ? It sound charger related but it's doing the same thing with 2 different chargers ,.. Batteries are about 3 years old