The charger on my boat can charge 3 battery banks but I only have 2 battery banks. What happens with the extra set of cables? Can you double-up the charging cables to one of the banks? - Brent
It depends on the model of the charger, some manufacturers want the 3rd lead unterminated and others want the leads doubled-up. You’ll need to read the manual to confirm how the 3rd lead should be wired.