[eagle801st]

I got my first pontoon boat last year and took the batteries out to charge during the winter. How do I reconnect them.

[MikeBear]

You connect them the reverse of how you disconnected them. RED wire goes to + (Positive) on the battery, and BLACK wire goes to - Negative.

We would need more details to narrow it down anymore than that. Name and model of pontoon boat, is it a gas motor, or electric motors, etc.

[MI-Roger]

Since your original posting title said you need 48 volts, and most car/marine batteries are 12 volt, I am guessing you have four batteries.

To achieve 48 volts from these four 12 volt batteries you must connect them in series. Positive on battery #1 to negative on battery #2, positive on battery #2 to negative on battery #3, positive on battery #3 to negative on battery #4.

Then you connect the positive on battery #4 to the red wire, and the negative on battery #1 to the black wire.

I would install a switch rated at 48 volts DC or greater so that you can make the final connections with an open circuit. Closing this switch will then safely (no arcing) power up your boat.