I am replacing an 8D battery deep cycle with three Group 24 deep cycle batteries wired in parallel. Total amps will be around the same, but easier to replace down the road (three small batts instead of one monster.) The second bank will be one Group 24 (used as starter)

On my Beneteau, the batt. terminals run thru on/off switches. Two red ones (one for each bank’s + ) and one black for the common ground (-). The battery charger (True Charge 40+) runs thru these switches. The load and charger go thru the same battery terminals for each bank..

Question: With the three batt. bank, Can I connect the terminal to the + on Battery #1 and the negative on Battery #3?

Some drawings I found show the + and – from one batt. Going to the load and the charger connected to + on one battery and – on the other battery. Refer to pages 2 (fig.3) and 7 (Fig.9) of this PDF.

http://www.nyc-arecs.org/Connecting_Batteries_and_Chargers_in_Series_and_Parallel.pdf

Thanks in advance for all the help this forum provides!! Marc