Re: Charging Two Batteries at the Same Time
You don't have to disconnect anything on the 24V battery bank to charge each battery. Connect the charger + & - to the first battery's + & - until it's charged, then place the chargers + & - on the second battery's + & - and charge.
IF you have an onboard charger with independent outputs you can connect the charger to both batteries at the same time, a pair of charger outputs go to each battery, so you can charge both batteries at the same time. (Don't do this with an automotive charger.)
An onboard charger is a good idea with trolling motor batteries as it's one heck of a lot easier to plug an extension cord into the charger and let it do it's thing,,, opposed to dragging the charger out, charging the first batt, then charging the second batt. Batteries left discharged will have a short life span, if it's easy charge them it will get done often, if it's difficult to charge them,,,, they will get neglected. The batteries should be charged as soon as you get home from fishing, not right before your next trip.