Well I took your advice, and heres what I got. Initially, battery B (trolling motor battery) was charged and green on the charger, and bank 3 was hooked up to battery C and was alternating red and green. I switched the leads between the two trolling batteries, and after doing so, bank 3 was STILL blinking. Now correct me if Im wrong, but if battery C was bad and I switched the leads from bank 2 to it, bank 2 would blink–but it doesnt, and bank 3 still blinks. All the wires are tight, and I checked the water in both batteries, and they were fine.Thanks for the help.